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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 1,513 records · Page 84
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Mshock, a thin layer Richtmyer-Meshkov instability experiment

The Mshock campaign is studying the feed through of the Richtmyer-Meshkov instability (RMI) in a thin layer in the high energy density (HED) regime. Experiments utilize a beryllium shock tube filled with low density foam and a high density plastic to study the instability. Initial experiments were performed at the OMEGA laser facility and recently at the National Ignition facility. While the basic design of the experiment is the same, critical components were changed to optimize the data quantity and clarity for the more energetic NIF.

42 ENGINEERING↗
DOE OSTI2021

Release of the NDI 2.2.0

The Nuclear Data Interface 2.2.0 has been released. It includes the addition of charged particle dE/dx (stopping power) data, the ability to read in NDI-formatted binary data, corrections to TN data, and other minor changes and bug fixes.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

Release of the NDI 2.2.0alpha

The Nuclear Data Interface 2.2.0alpha has been released. It includes the addition of charged particle dE/dx (stopping power) data, the ability to read in NDI-formatted binary data, corrections to TN data, CP 2011 and CP 2020 data, and other minor changes and bug fixes.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2023

High-Temperature Mobility of Tungsten Grain Boundaries

The objective of this study is to assess the effect of hydrogen isotopes on mechanical properties of tungsten relevant to first-wall applications in a tokamak. We report progress on calculation of the mobility of tungsten grain boundaries at high temperature, a key property in the process of recrystallization. In prior work we studied tungsten grain boundary properties such as the energies of boundaries with various orientations and misorientations, including energies of grain boundary phases that differ in structure from those at low temperature. We have calculated properties associated with the grain boundary mobility including the response of grain boundaries to applied shear stress. Here we report direct calculation of the motion of curved grain boundaries at high temperature using molecular dynamics. We compute how the mobility increases with temperature and how the mobility depends on the grain boundary misorientation. These calculations form baseline data to calculate the change when hydrogen or other defects are present.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Corrective Action Decision Document/Corrective Action Plan for Corrective Action Units 101 and 102: Central and Western Pahute Mesa Nevada National Security Site, Nevada, Revision 2

This revision was prepared to document changes to the data-collection activities. Specifically, the drilling and completion of the wells have been revised, and enhancements to the surface geophysics measurements have been included. Corrective action is needed because underground radioactive contamination exists in these areas resulting from historic underground nuclear testing. The PM CAUs are located in the northwestern portion of the Nevada National Security Site and comprise 82 corrective action sites. A total of 85 underground nuclear detonations took place within the area covered by the PM CAUs between 1965 and 1992 and resulted in the release of radionuclides in the subsurface in the vicinity of the test cavities.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Burleyson et al. 2020 Energy

Raw and processed data associated with the Burleyson et al. 2020 paper in Energy. The data needed to reproduce all figures in the paper is also included.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2021

Precise Dynamical Masses and Orbital Fits for β Pic b and β Pic c

We present a comprehensive orbital analysis to the exoplanets β Pictoris b and c that resolves previously reported tensions between the dynamical and evolutionary mass constraints on β Pic b. We use the Markov Chain Monte Carlo orbit code orvara to fit 15 years of radial velocities and relative astrometry (including recent GRAVITY measurements), absolute astrometry from Hipparcos and Gaia, and a single relative radial velocity measurement between β Pic A and b. We measure model-independent masses of 9.3{sub −2.5}{sup +2.6} M {sub Jup} for β Pic b and 8.3 ± 1.0 M {sub Jup} for β Pic c. These masses are robust to modest changes to the input data selection. We find a well-constrained eccentricity of 0.119 ± 0.008 for β Pic b, and an eccentricity of 0.21{sub −0.09}{sup +0.16} for β Pic c, with the two orbital planes aligned to within ∼05. Both planets’ masses are within ∼1σ of the predictions of hot-start evolutionary models and exclude cold starts. We validate our approach on N-body synthetic data integrated using REBOUND. We show that orvara can account for three-body effects in the β Pic system down to a level ∼5 times smaller than the GRAVITY uncertainties. Systematics in the masses and orbital parameters from orvara’s approximate treatment of multiplanet orbits are a factor of ∼5 smaller than the uncertainties we derive here. Future GRAVITY observations will improve the constraints on β Pic c’s mass and (especially) eccentricity, but improved constraints on the mass of β Pic b will likely require years of additional radial velocity monitoring and improved precision from future Gaia data releases.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1972

Importance of the splanchnic vascular bed in human blood pressure regulation.

Three-part experiment in which five subjects were exposed to lower body negative pressure (LBNP) at -50 mm Hg below the iliac crests. Duration of LBNP to earliest vagal symptoms was 7 to 21 min; all data are expressed as changes from control period to the last measurements before these symptoms. In part I, forearm blood flow (by Whitney gauge) fell 45% during LBNP. In part II, splanchnic blood flow (from arterial clearance hepatic extraction of indocyanine green) fell 32% and splanchnic vascular resistance rose 30%. In part III, cardiac output fell 28%, stroke volume 51%, and central blood volume 21%. Total peripheral resistance and heart rate rose 19% and 52%. Of the reduction in total vascular conductance, decreased splanchnic conductance accounted for approximately 33%; skin plus muscle conductance decreased similarly.

Rowell, L. B.↗
NASA NTRS1973

Additional thermal fatigue data on nickel- and cobalt-base superalloys, part 1

The fluidized bed technique was used to measure the relative thermal fatigue resistance of twenty-one superalloys. Among the thirty-six variations of composition, solidification method, and surface protection the cycles to cracking differed by two to three orders of magnitude. Some alloys suffered serious weight losses and oxidation. Thermal fatigue data, oxidation, and dimensional changes are reported. The types of superalloys are identified.

Howes, M. A. H.↗
NASA NTRS1973

Development of a rotating gravity gradiometer for earth orbit applications (AAFE)

Some preliminary mission studies are described along with the design, fabrication, and test of a breadboard model of an earth orbital, rotating gravity gradiometer with a design goal of 10 to the minus 11th power/sec sq (0.01 EU) in a 35-sec integration time. The proposed mission uses a Scout vehicle to launch one (or two orthogonally oriented) spin-stabilized satellites into a 330-km circular polar orbit some 20 days before an equinox. During the short orbital lifetime, the experiment would obtain two complete maps of the gravity gradient field with a resolution approaching 270 km (degree 75). The breadboard model of the gradiometer demonstrated a combined thermal and electronic noise threshold of 0.015 EU per data channel. The design changes needed to reduce the noise to less than 0.01 EU were identified. Variations of the sensor output signal with temperature were experimentally determined and a suitable method of temperature compensation was developed and tested. Other possible error sources, such as sensor interaction with satellite dynamics and magnetic fields, were studied analytically and shown to be small.

Forward, R. L.↗
NASA NTRS1973

Facilitating the exploitation of ERTS-1 imagery using snow enhancement techniques

The author has identified the following significant results. The applications of ERTS-1 imagery for geological fracture mapping regardless of season has been repeatedly confirmed. The enhancement provided by a differential cover of snow increases the number and length of fracture-lineaments which can be detected with ERTS-1 data and accelerates the fracture mapping process for a variety of practical applications. The geological mapping benefits of the program will be realized in geographic areas where data are most needed - complex glaciated terrain and areas of deep residual soils. ERTS-1 derived fracture-lineament maps which provide detail well in excess of existing geological maps are not available in the Massachusetts-Connecticut area. The large quantity of new data provided by ERTS-1 may accelerate and improve field mapping now in progress in the area. Numerous other user groups have requested data on the techniques. This represents a major change in operating philosophy for groups who to data judged that snow obscured geological detail.

Wobber, F. J.↗
NASA NTRS1973

Transport improvement, commuting costs, and residential location

A theoretical framework for evaluating the effects of introducing new transportation on residential travel patterns is presented. Data are based on changes in residential location of urban commuters that alter the mode and length of work trips as well as economic factors.

Stucker, J. P.↗
NASA NTRS1974

Interaction of gases with lunar materials

Quantitative efforts to assess the surface properties of lunar fines, particularly water induced porosity are discussed. Data show that: (1) changes induced in lunar fines are not visible in high energy electron micrographs, (2) scanning micrographs show no change in particle size distribution as a result of reaction with water, (3) water induced changes are internal to the particles themselves, (4) normal laboratory atmosphere blocks alteration reaction with water, and (5) surface properties of mature lunar soils appear to be almost independent of chemical composition and mineralogy, but there are some variations in their reactivity toward water.

Holmes, H. F.↗
NASA NTRS1973

The effect of bedrest on adrenal function

Eight male subjects were subjected to continuous bedrest for 24-80 weeks for the purpose of studying metabolic responses. Three of the subjects did supine exercises daily during part of the study. Adrenal function was examined in relation to adrenal cortical and medullary excretions. The results reveal an increase in hydrocortisone throughout the test period, a decrease in norepinephrine and no change in epinephrine. These data suggest that exercise could decrease the severity of deconditioning caused by bedrest.

Leach, C. S.↗
NASA NTRS1974

Inventory and monitoring of natural vegetation and related resources in an arid environment: A comprehensive evaluation of ERTS-1 imagery

The author has identified the following significant results. A vegetation classification, with 31 types and compatible with remote sensing applications, was developed for the test site. Terrain features can be used to discriminate vegetation types. Elevation and macrorelief interpretations were successful on ERTS photos, although for macrorelief, high sun angle stereoscopic interpretations were better than low sun angle monoscopic interpretations. Using spectral reflectivity, several vegetation types were characterized in terms of patterns of signature change. ERTS MSS digital data were used to discriminate vegetation classes at the association level and at the alliance level when image contrasts were high or low, respectively. An imagery comparison technique was developed to test image complexity and image groupability. In two stage sampling of vegetation types, ERTS plus high altitude photos were highly satisfactory for estimating kind and extent of types present, and for providing a mapping base.

Schrumpf, B. J.↗
NASA NTRS1975

Lunar heat-flow experiment: Long term temperature observations on the lunar surface at Apollo sites 15 and 17

Several investigators of the Apollo lunar experiments have observed gradual increases in the mean temperatures recorded by various surface thermometers. Similar effects were noticed in the temperatures of the thermometers of the Apollo 15 and 17 Heat Flow Experiments. An analysis of the long term temperature histories of the heat flow experiment thermometers is presented. These data show that no change in mean surface temperature at the Apollo 15 and 17 sites has occurred, and suggest that the slow increase in mean temperatures of thermometers in the electronics housing are due to changes in radiative properties of the housing's surfaces.

Peters, K.↗
NASA NTRS1975

An overview of NASA's space program

During the last several years, the NASA space program entered a new era. With the completion of the Apollo and Skylab programs, NASA places emphasis within its space effort on three main objectives: (1) improving the access to space and the ability to capitalize on this new capability; (2) developing the space and ground systems that will collect and interpret data related to the changing nature of the earth's natural and cultural resources to aid in solving resource and environmental problems facing the entire world; and (3) adding to the storehouse of knowledge through the continued exploration of our solar system and the universe. The paper discusses the importance of the joint USA/USSR Apollo-Soyuz Test Project (ASTP), describes the capability and status of the Space Shuttle, and outlines the important role that these two programs played in extending our ability to make more effective use of this space environment. It also summarizes the capability and the plans for satellites to monitor the earth's natural and cultural resources and to assess environmental quality. The NASA programs for exploring the solar system and the universe is reviewed.

Thome, P. G.↗