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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 1,423 records · Page 79
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Deployment of Water-Based Liquid Scintillator in ANNIE

ANNIE is a 26-ton water Cherenkov detector at Fermilab. Its main physics goals are to perform a measurement of the neutron yield from neutrino-nucleus interactions, as well as a measurement of the charged-current cross section of muon neutrinos. An equally important focus is the research and development of new detector technologies and target media. Specifically, water-based liquid scintillator (WbLS) is of interest as a novel detector medium, as it allows for the simultaneous detection of Cherenkov light and scintillation. This poster discusses the deployment of a WbLS filled vessel SANDI in ANNIE and the detection of both Cherenkov light and scintillation from the WbLS.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

ARES. II. Characterizing the Hot Jupiters WASP-127 b, WASP-79 b, and WASP-62b with the Hubble Space Telescope

This paper presents the atmospheric characterization of three large, gaseous planets: WASP-127 b, WASP-79 b, and WASP-62 b. We analyzed spectroscopic data obtained with the G141 grism (1.088–1.68 μm) of the Wide Field Camera 3 on board the Hubble Space Telescope using the Iraclis pipeline and the TauREx3 retrieval code, both of which are publicly available. For WASP-127 b, which is the least dense planet discovered so far and is located in the short-period Neptune desert, our retrieval results found strong water absorption corresponding to an abundance of log(H{sub 2}O) = −2.71{sub −1.05}{sup +0.78} and absorption compatible with an iron hydride abundance of log(FeH) = −5.25{sub −1.10}{sup +0.88}, with an extended cloudy atmosphere. We also detected water vapor in the atmospheres of WASP-79 b and WASP-62 b, with best-fit models indicating the presence of iron hydride, too. We used the Atmospheric Detectability Index as well as Bayesian log evidence to quantify the strength of the detection and compared our results to the hot Jupiter population study by Tsiaras et al. While all the planets studied here are suitable targets for characterization with upcoming facilities such as the James Webb Space Telescope and Ariel, WASP-127 b is of particular interest due to its low density, and a thorough atmospheric study would develop our understanding of planet formation and migration.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

XMM and NuSTAR Observations of an Optically Quiescent Quasar

Optically quiescent quasars (OQQs) represent a recently systematized class of infrared-luminous active galactic nuclei (AGNs) that have galaxy-like optical continua. They may represent an interesting, brief phase in the AGN life cycle, e.g., either cocooned within high-covering-factor media or indicative of recent triggering, though their nature remains unclear. Here, we present the first targeted simultaneous X-ray observations of an OQQ, our previously identified prototype, SDSS J075139.06+402811.2 at z = 0.587. The source is significantly detected over 0.5–16 keV with XMM-Newton and NuSTAR, unambiguously confirming the presence of current accretion activity. Spectral modeling yields an intrinsic luminosity L 2–10 keV ≈ 4.4 × 10 43 erg s -1 , well within the AGN regime, but underluminous relative to its infrared power. It is lightly obscured, with log N H [cm -2 ] ≈ 22.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1967

Thermal neutron image intensifier tube provides brightly visible radiographic pattern

Vacuum-type neutron image intensifier tube improves image detection in thermal neutron radiographic inspection. This system converts images to an electron image, and with electron acceleration and demagnification between the input target and output screen, produces a bright image viewed through a closed circuit television system.

Berger, H.↗
NASA NTRS1980

The use of radar and LANDSAT data for mineral and petroleum exploration in the Los Andes region, Venezuela

A geological study of a 27,500 sq km area in the Los Andes region of northwestern Venezuela was performed which employed both X-band radar mosaics and computer processed Landsat images. The 3.12 cm wavelength radar data were collected with horizontal-horizontal polarization and 10 meter spatial resolution by an Aeroservices SAR system at an altitude of 12,000 meters. The radar images increased the number of observable suspected fractures by 27 percent over what could be mapped by LANDSAT alone, owing mostly to the cloud cover penetration capabilities of radar. The approximate eight fold greater spatial resolution of the radar images made possible the identification of shorter, narrower fractures than could be detected with LANDSAT data alone, resulting in the discovery of a low relief anticline that could not be observed in LANDSAT data. Exploration targets for petroleum, copper, and uranium were identified for further geophysical work.

Vincent, R. K.↗
NASA NTRS1981

Observations of interstellar zinc

The International Ultraviolet Explorer observations of interstellar zinc toward 10 stars are examined. It is found that zinc is at most only slightly depleted in the interstellar medium; its abundance may serve as a tracer of the true metallicity in the gas. The local interstellar medium has abundances that apparently are homogeneous to within a factor of two, when integrated over paths of about 500 pc, and this result is important for understanding the history of nucleosynthesis in the solar neighborhood. The intrinsic errors in detecting weak interstellar lines are analyzed and suggestions are made as to how this error limit may be lowered to 5 mA per target observation.

Jura, M.↗
NASA NTRS1985

Development of an apparatus for obtaining molecular beams in the energy range from 2 to 200 eV

The formation and detection of molecular beams obtained by charge exchange from a low-energy ion source is discussed. Dispersion in energy of the ion source was measured and problems concerning detection of neutral beams were studied. Various methods were used, specifically secondary electron emissivity of a metallic surface and ionization of a gas target with a low ionization voltage. The intensities of neutral beams as low as 10 eV are measured by a tubular electron multiplier and a lock-in amplifier.

Clapier, R.↗
NASA NTRS1986

Analysis of AIS radiometry at Mono Lake, California

Airborne imaging spectrometer (AIS) data were studied to establish absolute instrumental calibration and to provide atmospheric corrections. Good agreement is found between calculated and measured radiances for uniform surface targets (beaches), but simulations of atmospheric properties with LOWTRAN lead to unreasonably low values of atmospheric precipitable water. Absorptions from CO2 are not detected in the AIS data, but are strongly present in the LOWTRAN model. The apparent low contrast of all atmospheric absorption bands leads to a study of contamination from overlapping spectral orders in the AIS data. The suspected contamination is shown unambiguously to be present beyond 1500 nm. The magnitude remains uncertain. Spectral band filling at 1400 nm cannot be accounted for by order mixing because of the 800 nm blocking filter used. Rough corrections for short wavelength mode observations might be possible if an after-the-fact radiometric calibration of the instrument can be developed.

Conel, J. E.↗
NASA NTRS1996

Relativity effects for space-based coherent lidar experiments

An effort was initiated last year in the Astrionics Laboratory at Marshall Space Flight Center to examine and incorporate, if necessary, the effects of relativity in the design of space-based lidar systems. A space-based lidar system, named AEOLUS, is under development at Marshall Space Flight Center and it will be used to accurately measure atmospheric wind profiles. Effects of relativity were also observed in the performance of space-based systems, for example in case of global positioning systems, and corrections were incorporated into the design of instruments. During the last summer, the effects of special relativity on the design of space-based lidar systems were studied in detail, by analyzing the problem of laser scattering off a fixed target when the source and a co-located receiver are moving on a spacecraft. Since the proposed lidar system uses a coherent detection system, errors even in the order of a few microradians must be corrected to achieve a good signal-to-noise ratio. Previous analysis assumed that the ground is flat and the spacecraft is moving parallel to the ground, and developed analytical expressions for the location, direction and Doppler shift of the returning radiation. Because of the assumptions used in that analysis, only special relativity effects were involved. In this report, that analysis is extended to include general relativity and calculate its effects on the design.

Gudimetla, V. S. Rao↗
NASA NTRS1998

SPARCLE: Validation of Observing System Simulations (SPace Readiness Coherent Lidar Experiment)

NASA recently approved a mission to fly a Doppler Wind Lidar (DWL) on a U.S. Space Shuttle. SPARCLE, managed by Marshall Space Flight Center in Huntsville, AL, is targeted for launch in March 2001. This mission is viewed as a necessary demonstration of a solid state (2 micron) lidar using coherent detection before committing resources to a 3-5 year research or operational mission. While, to many, this shuttle mission is seen as the first step in a series leading to a fully operational wind observing system, to others, it is a chance to validate predictions of performance based upon theoretical models, analyses of airborne and ground-based data, and sophisticated observing system simulation experiments. This paper will be presented in two parts: first a brief overview of the SPARCLE mission and second, a summary of current performance predictions and key contributions from ground- based and airborne DWL research. The SPARCLE instrument is a 100 mJ, 6 Hz, diode-pumped 2-micron laser with a .25 m telescope using heterodyne mixing in a fiber and an InGaAs detector. A 25 cm silicon wedge scanner will be used in step-stare modes with dwells ranging from 60 seconds to .5 seconds. Pointing knowledge is achieved with a dedicated GPS/INS mounted close to the lidar. NASA's Hitchhiker program is providing the instrument enclosures (2 cans) and mission logistics support. An on-board data system is sized to record 150 Gbytes of raw signal from a two 400 MHZ A/D converters. On-board signal processing will be used to control the frequency of the Local Oscillator. SPARCLE is predicted to have a single shot backscatter sensitivity near 1x10(exp -6) m-1 sr-1, To achieve higher sensitivity, shot accumulation will be employed. Ground-based, 2 micron DWLs have been used to assess the benefits of shot accumulation (approximately SQRT for SNR). Airborne programs like MACAWS have provided good datasets for evaluating various sampling strategies and signal processing algorithms. Using these real data to calibrate our simulation models, we can describe when and how well SPARCLE is expected to preform. Outputs from these performance models will be presented.

Emmitt, G. D.↗
NASA NTRS2004

Volcanic Activity at Tvashtar Catena, Io

Tvashtar Catena (63 N, 120 W) is one of the most interesting features on Io. This chain of large paterae (caldera-like depressions) has exhibited highly variable volcanic activity in a series of observations. Tvashtar is the type example of a style of volcanism seen only at high latitudes, with short-lived Pele-type plumes and short-lived by intense thermal events. Evidence for a hot spot at Tvashtar was first detected in an eclipse observation in April 1997 (orbit G7) by the Solid State Imager (SSI) on the Galileo Spacecraft. Tvashtar was originally targeted for observation at higher resolution in the close flyby in November 1999 (I25) because of its interesting large-scale topography. There are relatively few but generally larger paterae at high latitudes on Io. I25 images revealed a 25 km long, 1-2 km high lava curtain via a pattern of saturation and bleeding in the CCD image, which requires very high temperatures.

Milazzo, M. P.↗
NASA NTRS2001

Routine detection of Epstein-Barr virus specific T-cells in the peripheral blood by flow cytometry

The ability to detect cytomegalovirus-specific T-cells (CD4(+)) in the peripheral blood by flow cytometry has been recently described by Picker et al. In this method, cells are incubated with viral antigen and responding (cytokine producing) T-cells are then identified by flow cytometry. To date, this technique has not been reliably used to detect Epstein-Barr virus (EBV)-specific T-cells primarily due to the superantigen/mitogenic properties of the virus which non-specifically activate T-cells. By modifying culture conditions under which the antigens are presented, we have overcome this limitation and developed an assay to detect and quantitate EBV-specific T-cells. The detection of cytokine producing T-cells by flow cytometry requires an extremely strong signal (such as culture in the presence of PMA and ionomycin). Our data indicate that in modified culture conditions (early removal of viral antigen) the non-specific activation of T-cells by EBV is reduced, but antigen presentation will continue uninhibited. Using this method, EBV-specific T-cells may be legitimately detected using flow cytometry. No reduction in the numbers of antigen-specific T-cells was observed by the early removal of target antigen when verified using cytomegalovirus antigen (a virus with no non-specific T-cell activation properties). In EBV-seropositive individuals, the phenotype of the EBV-specific cytokine producing T-cells was evaluated using four-color flow cytometry and found to be CD45(+), CD3(+), CD4(+), CD45RA(-), CD69(+), CD25(-). This phenotype indicates the stimulation of circulating previously unactivated memory T-cells. No cytokine production was observed in CD4(+) T-cells from EBV-seronegative individuals, confirming the specificity of this assay. In addition, the use of four color cytometry (CD45, CD3, CD69, IFNgamma/IL-2) allows the total quantitative assessment of EBV-specific T-cells while monitoring the interference of EBV non-specific mitogenic activity. This method may have significant utility for the monitoring of the immune response to latent virus infection/reactivation.

Non-NASA Center↗
NASA NTRS2018

The HOSTS Survey-Exozodiacal Dust Measurements for 30 Stars

The Hunt for Observable Signatures of Terrestrial Systems survey searches for dust near the habitable zones (HZs) around nearby, bright main-sequence stars. We use nulling interferometry in the N band to suppress the bright stellar light and to probe for low levels of HZ dust around the 30 stars observed so far. Our overall detection rate is 18%, including four new detections, among which are the first three around Sun-like stars and the first two around stars without any previously known circumstellar dust. The inferred occurrence rates are comparable for early-type and Sun-like stars, but decrease from 60(sup +16)(sub -21)% for stars with previously detected cold dust to 8(sup +10)(sub -3)% for stars without such excess, confirming earlier results at higher sensitivity. For completed observations on individual stars, our sensitivity is five to ten times better than previous results. Assuming a lognormal excess luminosity function, we put upper limits on the median HZ dust level of 13 zodis (95% confidence) for a sample of stars without cold dust and of 26 zodis when focusing on Sun-like stars without cold dust. However, our data suggest that a more complex luminosity function may be more appropriate. For stars without detectable Large Binocular Telescope Interferometer (LBTI) excess, our upper limits are almost reduced by a factor of two, demonstrating the strength of LBTI target vetting for future exo-Earth imaging missions. Our statistics are limited so far, and extending the survey is critical to informing the design of future exo-Earth imaging surveys.

The Hunt for Observable Signatures of Terrestrial ↗
NASA NTRS2022

General Services Administration Reclamation Yard, SWMU 010, 2021 Groundwater Monitoring Report

This report presents a summary of the groundwater monitoring activities that occurred in November and December 2021 at General Services Administration Reclamation Yard, Solid Waste Management Unit 010, located at the John F. Kennedy Space Center (KSC), Florida. The site is monitored under KSC’s Resource Conservation and Recovery Act Corrective Action Program. This approach also meets the requirements of Chapter 62-780, Florida Administrative Code. For the purposes of this report, two separate plumes, known as the Polychlorinated Biphenyl (PCB)/Volatile Organic Aromatic (VOA) Plume and the Chlorinated Volatile Organic Compound (VOC) Plume, were identified for this site. The contaminants of concern (COCs) for the PCB/VOA Plume consists of PCBs, 1,2,4-trichlorobenzene, and breakdown products of 1,2,4-trichlorobenzene. The COCs for the Chlorinated VOC Plume are tetrachloroethene, trichloroethene, cis-1,2-dichloroethene, and vinyl chloride. The activities presented in this report include two field events: (1) November 2021 – PCB/VOA Plume groundwater sampling via Direct Push Technology – 70 groundwater samples were collected from 10 locations at varying intervals; and (2) December 2021 – Site-wide semi-annual water level measurements of 54 monitoring wells, redevelopment of 5 monitoring wells, and sampling of 35 monitoring wells. Results for the PCB/VOA plume demonstrated COCs have not rebounded since the 2018 source removal, with groundwater cleanup target levels (GCTLs) exceeded in the 10-30 ft. below ground surface interval only. In the Chlorinated VOC plume area, there were no detections of COCs above a GCTL for at least the second consecutive sampling event for the sampled wells. Cleanup objectives have been met, and it is recommended that VOC monitoring be discontinued. Underground injection control parameters will continue to be monitored in three wells until those analytes return to background concentrations.

GSA Reclamation Yard↗
NASA NTRS2023

Development of a Photoacoustic Formaldehyde Monitor

Key indoor air quality pollutant formaldehyde (H2CO) is tracked on International Space Station (ISS) using passive badges returned to the ground periodically for analysis. The process is time-consuming both in preparation and for analysis upon return 6-12 months later. Badges also require precious crew time for deploy, retrieval and stow. As NASA’s focus in space exploration shifts to the Moon and Mars, archival sample return becomes increasingly impractical, so the aim of this project is to develop a highly reliable real-time analyzer for H2CO at low concentrations with data downlinked. Potential sources of H2CO include materials off gassing, use of formalin as a tissue fixative in biological payloads and overheating of acetal polymers. The Spacecraft Maximum Allowable Concentration (SMAC) for H2CO is 100 ppb for exposures of 7 days or longer. ISS concentrations recently run only 10 - 30 ppb but have spiked as high as 60 ppb in the past. Gateway real time monitoring requirements call for a range of 8 - 140 ppb. For this project, a concentration range of 5 - 500 ppb H2CO is targeted. The core tunable diode laser spectroscopy (TDLS) technology was developed by Vista Photonics through the NASA and US Navy Small Business Innovation Research (SBIR) programs. Monitors based on this technology have been demonstrated on ISS, trialed on a nuclear submarine and are in production as Anomaly Gas Analyzers for both ISS and Orion. Initially, direct absorption TDLS was used exclusively in these monitors, however, the H2CO target concentration is much lower, and a longer wavelength required, so a photoacoustic spectroscopy (PAS) technique was adapted, where the laser excitation is detected by a sensitive microphone vs. a conventional photodetector. This paper will discuss the results of NASA-JSC laboratory testing of a prototype PAS based formaldehyde monitor and explore potential adaptations for Gateway missions and beyond.

Paul D Mudgett↗
DOE OSTI2024

Using Fiducial Markers for Pose Estimation of an OSWEC in a Wave Tank: Preprint

In this study, we consider a novel method of sensing the motion of a wave energy converter during testing in a wave flume under the influence of incoming waves. The wave energy converter considered in our research is an oscillating surge wave energy converter, which is a hinged paddle that responds to incoming waves. Motion sensing is normally done with inertial sensors, which can hinder the motion due to suspended cables that carry power and transmit signals. Our proposed method is contactless and can be implemented economically. A camera is used to record different marker patterns affixed to the moving paddle and the motion deduced by pose estimation algorithms. Fiducial markers are commonly used for robot localization and in augmented reality. There are many types of fiducial markers, including ArUco-type markers which are accurate, fast and robust. The system consists of markers attached to the paddle element and recorded using a machine vision camera. A pose estimation algorithm is then applied to the detected markers to estimate the tilt of the paddle. In this work, we examine the challenges of image acquisition and calibration for underwater targets, compare the motion obtained by this new system with a calibrated tilt sensor and identify areas where the new system may be superior.

computer vision↗
DOE OSTI2024

Underwater unexploded ordnance discrimination based on intrinsic target polarizabilities – A case study

Seabed unexploded ordnance that resulted partly from the high failure rate among munitions from more than 80 years ago and from decades of military training and testing of weapons systems poses an increasing concern all around the world. Although existing magnetic systems can detect clusters of debris, they are not able to tell whether a munition is still intact requiring special removal (e.g. in situ detonation) or is harmless scrap metal. The marine environment poses unique challenges, and transferring knowledge and approaches from land to a marine environment has not been easy and straightforward. On land, the background soil conductivity is much lower than the conductivity of the unexploded ordnance and the electromagnetic response of a target is essentially the same as that in free space. For those frequencies required for target characterization in the marine environment, the seawater response must be accounted for and removed from the measurements. The system developed for this study uses fields from three orthogonal transmitters to illuminate the target and four three-component receivers to measure the signal arranged in a configuration that inherently cancels the system's response due to the enclosing seawater, the sea–bottom interface and the air–sea interface for shallow deployments. The system was tested as a cued system on land and underwater in San Francisco Bay – it was mounted on a simple platform on top of a support structure that extended 1 m below and allowed the diver to place metal objects to a specific location even in low-visibility conditions. The measurements were stable and repeatable. Furthermore, target responses estimated from marine measurements matched those from land acquisition, confirming that the seawater and air–sea interface responses were removed successfully. Thirty-six channels of normalized induction responses were used for the classification, which was done by estimating the target principal dipole polarizabilities. Our results demonstrated that the system can resolve the intrinsic polarizabilities of the target, with clear distinctions between those of symmetric intact unexploded ordnance and irregular scrap metal. The prototype system was able to classify an object based on its size, shape and metal content and correctly estimate its location and orientation.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2020

Detection of Head and Neck Cancer Based on Longitudinal Changes in Serum Protein Abundance

Head and Neck Squamous Cell Carcinoma (HNSCC) is significantly represented in the military population with substantial impact on military operations. Two-thirds of new HNSCC cases are first diagnosed at advanced stage III or IV with lymph node metastases. Thus, there is an urgent need of biomarkers for early detection and risk stratification. Archived serum samples from the Department of Defense Serum Repository provide a unique resource for longitudinal studies of HNSCC in the military and the identification of early detection biomarkers. Methods: We identified 175 patients diagnosed with HNSCC with 175 matched healthy controls and retrieved a total of 978 serum samples drawn at the time of diagnosis, 2 and 4 years prior to diagnosis, and 2 years after diagnosis. Following immunoaffinity depletion, serum samples were analyzed by targeted proteomics assays for multiplexed quantification of a panel of 146 candidate protein biomarkers from the curated literature. Results: We derived a 13-protein signature that distinguishes case versus controls based on longitudinal changes in serum protein concentration. The abundances of each of the 13 proteins remain constant over time in control subjects. The area under the curve for the derived random forest classifier was 0.90. Conclusions: This 13-protein classifier is highly promising for detection of HNSCC prior to overt symptoms. Impact: Use of longitudinal samples has significant potential to identify biomarkers for detection and risk stratification.

59 BASIC BIOLOGICAL SCIENCES↗