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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 1,639 records · Page 91
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

A global database of dissolved organic matter (DOM) concentration measurements in coastal waters (CoastDOM v1)

Abstract. Measurements of dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) concentrations are used to characterize the dissolved organic matter (DOM) pool and are important components of biogeochemical cycling in the coastal ocean. Here, we present the first edition of a global database (CoastDOM v1; available at https://doi.org/10.1594/PANGAEA.964012, Lønborg et al., 2023) compiling previously published and unpublished measurements of DOC, DON, and DOP in coastal waters. These data are complemented by hydrographic data such as temperature and salinity and, to the extent possible, other biogeochemical variables (e.g. chlorophyll a, inorganic nutrients) and the inorganic carbon system (e.g. dissolved inorganic carbon and total alkalinity). Overall, CoastDOM v1 includes observations of concentrations from all continents. However, most data were collected in the Northern Hemisphere, with a clear gap in DOM measurements from the Southern Hemisphere. The data included were collected from 1978 to 2022 and consist of 62 338 data points for DOC, 20 356 for DON, and 13 533 for DOP. The number of measurements decreases progressively in the sequence DOC > DON > DOP, reflecting both differences in the maturity of the analytical methods and the greater focus on carbon cycling by the aquatic science community. The global database shows that the average DOC concentration in coastal waters (average ± standard deviation (SD): 182±314 µmol C L−1; median: 103 µmol C L−1) is 13-fold higher than the average coastal DON concentration (13.6±30.4 µmol N L−1; median: 8.0 µmol N L−1), which is itself 39-fold higher than the average coastal DOP concentration (0.34±1.11 µmol P L−1; median: 0.18 µmol P L−1). This dataset will be useful for identifying global spatial and temporal patterns in DOM and will help facilitate the reuse of DOC, DON, and DOP data in studies aimed at better characterizing local biogeochemical processes; closing nutrient budgets; estimating carbon, nitrogen, and phosphorous pools; and establishing a baseline for modelling future changes in coastal waters.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1971

Piping and tubing technology: A compilation

A compilation on the devices, techniques, and methods used in piping and tubing technology is presented. Data cover the following: (1) a number of fittings, couplings, and connectors that are useful in joining tubing and piping and various systems, (2) a family of devices used where flexibility and/or vibration damping are necessary, (3) a number of devices found useful in the regulation and control of fluid flow, and (4) shop hints to aid in maintenance and repair procedures such as cleaning, flaring, and swaging of tubes.

Source record↗
NASA NTRS1972

FGRAAL: Technical documentation

Implementation of FGRAAL, a FORTRAN-extended graph algorithmic language for the Univac 1108 is described. The report contains the description of the implemented data structures for sets, lists and graphs. It summarizes the changes made for the RALPH compiler to accommodate the special statements of FGRAAL; gives the calling sequences generated by the changed compiler; and describes the object time subroutine package.

Mesztenyi, C. K.↗
NASA NTRS1974

Cables and connectors: A compilation

A technological compilation on devices and techniques for various types of electrical cables and connections is presented. Data are reported under three sections: flat conductor cable technology, newly developed electrical connectors, and miscellaneous articles and information on cables and connector techniques.

Source record↗
NASA NTRS1978

The composition of Phobos - Evidence for carbonaceous chondrite surface from spectral analysis

In connection with a need for more definitive information concerning the composition of Phobos in a study of its origin, an ultraviolet-visible-infrared reflectance spectrum of the Martian satellite was compiled from the Mariner 9 ultraviolet spectrometer, Viking lander imaging, and ground-based photometric data. The probable surface composition of Phobos was deduced by comparing the obtained spectrum with the spectra of asteroids of known composition. The considered data show that the reflectivity of Phobos is flat from 1100 to 400 nm but decreases sharply in the ultraviolet to about 1 percent at 212 nm. The reflectance spectrum is similar to the spectra of asteroids Ceres and Pallas which were found to have surface compositions similar to that of carbonaceous chondrites. It is concluded that the surface composition of Phobos is also similar to that of carbonaceous chondrites. The results of the investigation point to different modes of origin for Mars and Phobos.

Pang, K. D.↗
NASA NTRS1982

Documentation for the machine-readable version of the general catalogue of trigonometric stellar parallaxes and supplement

The machine-readable version of the General Catalog of Trigonometric Stellar parallaxes as distributed by the Astronomical Data Center is described. It is intended to enable users to read and process the data without problems and guesswork. The source reference should be consulted for details concerning the compilation of the main catalogue and supplement, the probable errors, and the weighting system used to combine determinations from different observatories.

Warren, W. H., Jr.↗
NASA NTRS1987

Down-to-earth supercomputing at NASA Ames

The requirements for computers for aerospace vehicle design problems, in particular fluid dynamics, are examined. The levels of approximation to Navier-Stokes equations are: (1) linearized inviscid form, (2) nonlinear inviscid equation, (3) Reynolds-averaged Navier-Stokes equation, (4) large eddy simulation with models for subgrid scale turbulence, and (5) full Navier-Stokes equations to calculate laminar/turbulent transition and turbulence dissipation. The Cray 2 with 256 megaword memory and 4.1 nsec clock and the Cray X-MP/48 with a 128 megaword memory and a 9.5 nsec clock of the Ames facility are described, and an example revealing their applicability is presented. The use of zonal methods to simulate aerodynamic flow fields numerically is discussed. Consideration is given to the development of a program for simulation of aerodynamic flow fields, the compilers, symbolic debuggers, the scheduling of multiple CPUs, and the analysis and storage of the data.

Stevens, Kenneth G., Jr.↗
NASA NTRS1988

Intrinsic integrated UBVRI colors of Galactic globular clusters

Published observational data on 50 Galactic globular clusters, including spectral classifications, homogenized colors, and color excesses, are compiled in extensive tables, graphs, and diagrams and analyzed to determine the intrinsic-color/integrated-spectral-type relationship in the UBVRI system. These relationships are found to exhibit significant slopes, although the RI colors do not contribute substantially to the intrinsic-color determination. The values of a(B-V) for the northern and southern Galactic hemispheres are found to be 0.068 + or - 0.006 and 0.039 + or - 0.003 mag, respectively.

Reed, B. Cameron↗
NASA NTRS1988

Critical velocity experiments in space

Published data from active space experiments designed to demonstrate the Alfven critical-velocity effect are compiled in graphs and compared with the predictions of numerical simulations. It is found that the discrepancies in the ionization yields obtained in shaped-charge releases of alkali metals are related to the macroscopic limits of time and energy in such releases. It is argued that the total ionization yield is an inadequate measure of the critical-velocity effect, and a new criterion based on eta, the efficiency of energy transfer from the recently ionized neutrals to a heated electron population, is proposed: the effect would be verified if eta values of 10 percent or greater were observed.

Torbert, R. B.↗
NASA NTRS1991

Attitude profile design program

The Attitude Profile Design (APD) Program was designed to be used as a stand-alone addition to the Simplex Computation of Optimum Orbital Trajectories (SCOOT). The program uses information from a SCOOT output file and the user defined attitude profile to produce time histories of attitude, angular body rates, and accelerations. The APD program is written in standard FORTRAN77 and should be portable to any machine that has an appropriate compiler. The input and output are through formatted files. The program reads the basic flight data, such as the states of the vehicles, acceleration profiles, and burn information, from the SCOOT output file. The user inputs information about the desired attitude profile during coasts in a high level manner. The program then takes these high level commands and executes the maneuvers, outputting the desired information.

Source record↗
NASA NTRS1989

Prediction of the He distribution at the lunar surface

Data on the contents of He and TiO2 and the maturity index, Is/FeO have been compiled, for all lunar soils for which measurements have been reported, in order to quantitatively asses the relationship between these parameters. The He content in lunar soils correlates approximately linearly with the product (Is/FeO)(TiO2 wt pct) over the range of measured values. The advantage of such a trend is the assistance it may provide in mapping the lunar surface for He and other solar-wind volatiles in a quantitative manner. A remote means of assessing Is/FeO in addition to TiO2 will be required.

Jordan, J. L.↗
NASA NTRS1998

Enhancement to Hitran to Support the NASA EOS Program

The HITRAN molecular database has been enhanced with the object of providing improved capabilities for the EOS program scientists. HITRAN itself is the database of high-resolution line parameters of gaseous species expected to be observed by the EOS program in its remote sensing activities. The database is part of a larger compilation that includes IR cross-sections, aerosol indices of refraction, and software for filtering and plotting portions of the database. These properties have also been improved. The software has been advanced in order to work on multiple platforms. Besides the delivery of the compilation on CD-ROM, the effort has been directed toward making timely access of data and software on the world wide web.

Kirby, Kate P.↗
NASA NTRS1999

Enhancement to HITRAN to Support the NASA EOS Program

The HITRAN molecular database has been enhanced with the object of providing improved capabilities for the EOS program scientists. HITRAN itself is the database of high-resolution line parameters of gaseous species expected to be observed by the EOS program in its remote sensing activities. The database is part of a larger compilation that includes IR cross-sections, aerosol indices of refraction, and software for filtering and plotting portions of the database. These properties have also been improved. The software has been advanced in order to work on multiple platforms. Besides the delivery of the compilation on CD-ROM, the effort has been directed toward making timely access of data and software on the world wide web.

Kirby, Kate P.↗
NASA NTRS2010

Lunar Meteorites: What They Tell us About the Spatial and Temporal Distribution of Mare Basalts

Here we analyze the chronology and statistical distribution of lunar meteorites with emphasis on the spatial and temporal distribution of lunar mare basalts. The data are mostly from the Lunar Meteorite Compendium (http://www-curator.jsc.nasa.gov/ antmet/ lmc/contents.cfm cited hereafter as Compendium) compiled by Kevin Righter, NASA Johnson Space Center, and from the associated literature. The Compendium was last modified on May 12, 2008.

Basilevsky, A. T.↗
DOE OSTI2026

Ecological Insights from Transferable Plant Biomass Mapping across the Arctic using High-resolution Structure-from-Motion and LiDAR Data

Warmer temperatures, permafrost thaw, and increased wildfire activity are driving rapid ecological change across the Arctic, significantly altering plant productivity and aboveground biomass (AGB). These rapid changes highlight the urgent need to improve monitoring of vegetation dynamics in the Earth’s northern ecosystems, where high spatiotemporal heterogeneity occurs at scales finer than those captured by traditional satellite observations. The growing use of Unoccupied Aerial Systems (UASs) presents an opportunity to overcome this limitation. Yet, the diversity of UAS platforms, sensors, and data collection and processing workflows presents challenges for developing standardized, generalizable approaches. To address this challenge, we compiled 672 AGB plots co-located with 183 UAS-based Structure-from-Motion (SfM) or Light Detection and Ranging (LiDAR) surveys collected across the Arctic. Here, we: (1) evaluated the generalizability of UAS-derived canopy structure derived from high-resolution SfM and LiDAR for estimating AGB, (2) assessed scaling errors and their sources in two recent satellite-based AGB products derived from Landsat and MODIS, and (3) demonstrated the use of high-resolution AGB maps to quantify biomass variation across tundra plant functional types (PFTs) and to monitor post-fire recovery. Our results show that both SfM and LiDAR accurately captured AGB and its variability across tundra PFTs using a Random Forest (RF) model (overall RMSE: 0.336 kg/m2), with mapping performance varying slightly by region and data source. Using UAS-derived AGB maps as a benchmark, we identified systematic biases in satellite-derived AGB products, largely attributable to the magnitude of AGB and structural heterogeneity within coarse-resolution pixels. Applying our model to repeat UAS surveys following a tundra fire on Seward Peninsula, we observed rapid AGB recovery in non-shrub patches, with biomass recovering to pre-fire levels within 2 years. In contrast, shrub patches recovered more slowly, with AGB gains continuing over 2–4 years through both in-patch growth and lateral expansion (via dispersal) into remaining burned areas. Overall, these findings demonstrate the generalizability of UAS-based SfM and LiDAR data for estimating tundra AGB and highlight the potential of our approach to be broadly applied to generate high-quality AGB data for ecological monitoring and model benchmarking across the Arctic.

Yang, Daryl [ORNL] (ORCID:0000000317057823)↗
NASA NTRS2014

Maneuver Acoustic Flight Test of the Bell 430 Helicopter Data Report

A cooperative ight test by NASA, Bell Helicopter and the U.S. Army to characterize the steady state acoustics and measure the maneuver noise of a Bell Helicopter 430 aircraft was accomplished. The test occurred during June/July 2011 at Eglin Air Force Base, Florida. This test gathered a total of 410 test points over 10 test days and compiled an extensive database of dynamic maneuver measurements. Three microphone arrays with up to 31 microphon. es in each were used to acquire acoustic data. Aircraft data included Differential Global Positioning System, aircraft state and rotor state information. This paper provides an overview of the test and documents the data acquired.

Watts, Michael E.↗
NASA NTRS2016

Features of the Upgraded Imaging for Hypersonic Experimental Aeroheating Testing (IHEAT) Software

The Imaging for Hypersonic Experimental Aeroheating Testing (IHEAT) software is used at the NASA Langley Research Center to analyze global aeroheating data on wind tunnel models tested in the Langley Aerothermodynamics Laboratory. One-dimensional, semi-infinite heating data derived from IHEAT are used in the design of thermal protection systems for hypersonic vehicles that are exposed to severe aeroheating loads, such as reentry vehicles during descent and landing procedures. This software program originally was written in the PV-WAVE(Registered Trademark) programming language to analyze phosphor thermography data from the two-color, relative-intensity system developed at Langley. To increase the efficiency, functionality, and reliability of IHEAT, the program was migrated to MATLAB(Registered Trademark) syntax and compiled as a stand-alone executable file labeled version 4.0. New features of IHEAT 4.0 include the options to perform diagnostic checks of the accuracy of the acquired data during a wind tunnel test, to extract data along a specified multi-segment line following a feature such as a leading edge or a streamline, and to batch process all of the temporal frame data from a wind tunnel run. Results from IHEAT 4.0 were compared on a pixel level to the output images from the legacy software to validate the program. The absolute differences between the heat transfer data output from the two programs were on the order of 10(exp -5) to 10(exp -7). IHEAT 4.0 replaces the PV-WAVE(Registered Trademark) version as the production software for aeroheating experiments conducted in the hypersonic facilities at NASA Langley.

Mason, Michelle L.↗