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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 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Analysis of surfaces from the LDEF A0114, phase 2

During the reporting period, work continued on profilometry measurements of eroded and corroded sample surfaces, optical transmission measurements, analysis of the pinhole camera, and x-ray photoelectron spectroscopy (XPS) analysis of some samples. Among metal samples, copper showed some interesting new results. There were two forms of copper samples: a thin film sputter-coated on fused silica and a solid piece of OFHC copper. They were characterized by x-ray and Auger electron spectroscopies, x-ray diffraction, and high resolution profilometry. Cu 2p core level spectra were used to demonstrate the presence of Cu2O and CuO and to determine the oxidation states.

Gregory, John C.↗
DOE OSTI2020

Hyporheic, Floodplain, and Surface Water (on Floodplain and River) Geochemical Datasets, and Shapefiles on Meander C at the East River, Colorado

The purpose of this dataset was to sample surface water and groundwater geochemistry at random locations in the East River, Colorado to provide a broad spatial dataset of geochemistry. The East River is part of the Watershed Function Scientific Focus Area (WFSFA) located in the Upper Colorado River Basin, United States. We conducted this random sampling at multiple time points including during the snowmelt flooding stage, during peak flood, during the falling limb of flood, and during baseflow. This datasets contain many datafiles. We include flat text files of surface water geochemistry including surface water on the floodplain and surface water in the river, geochemistry of floodplain pore-water samples, and geochemistry of hyporheic pore-water samples. All datasets are also included as shapefiles so location geochemistry is co-located with sampling locations and sampling depths. This datasets also has the locations of small channels, and hollows that are on top of floodplain Meander C. These small channels funnel surface water from the hillslope through the floodplain and out to the river. All text datasets can be analyzed with software such as Excel or R. All shapefiles can be viewed with freely available R packages such as Leaflet.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Spin-polarized scanning tunneling microscopy experiments on the rough surface of a polycrystalline NiFe film with a fine magnetic tip sensitive to a well-defined magnetization component

We developed a micrometer-sized magnetic tip integrated onto the write head of a hard disk drive for spin-polarized scanning tunneling microscopy (SP-STM) in the modulated tip magnetization mode. Using SP-STM, we measured a well-defined in-plane spin-component of the tunneling current of the rough surface of a polycrystalline NiFe film. The spin asymmetry of the NiFe film was about 1.3% within the bias voltage range of -3 to 1 V. We obtained the local spin component image of the sample surface, switching the magnetic field of the sample to reverse the sample magnetization during scanning. We also obtained a spin image of the rough surface of a polycrystalline NiFe film evaporated on the recording medium of a hard disk drive.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1991

Analysis of surfaces from the LDEF A0114, phase 4

Progress made from 1 Mar. to 31 Aug. 1991 is presented. The work concentrated on profilometry measurements of eroded and corroded sample surfaces, optical transmission measurements, analysis of the pinhole camera, and x-ray photoelectron spectroscopic (XPS) analysis of some samples. The following papers are presented: (1) observation of Be-7 on the surface of the Long Duration Exposure Facility (LDEF) Spacecraft; (2) measurement of the passive attitude control performance of a recovered spacecraft; (3) effects on LDEF exposed copper flim and bulk; (4) measurements of erosion characteristics for metal and polymer surfaces using profilometry; (5) the interactions of atmospheric cosmogenic radionuclides with spacecraft surfaces; (6) pinhole cameras as sensors for atomic oxygen in orbit; and (7) interaction of atomic oxygen with solid surfaces in low earth orbit- results from LDEF experiment A0114.

Gregory, John C.↗
DOE OSTI2022

Degradation mechanism of blended cement pastes in sulfate-bearing environments under applied electric fields: Sulfate attack vs. decalcification

Applied electric fields, the reason behind stray currents, accelerate the ingress of sulfate into cementitious materials. To identify mitigation approaches, this study investigates the effects of slag and fly ash on sodium sulfate attacks of cement pastes under a constant electric current. The mineralogical alterations induced by the attacks were analyzed using X-ray diffractometry, thermogravimetric analysis, scanning electron microscopy, and thermodynamic modeling. The dissolution of aluminates in the slag and fly ash induced a monosulfate-rich area (>~20 mm from the cathode surface) to form next to the ettringite-rich area on the sample surface (<~20 mm). This effect reduced the availability of SO 4 2– in the pore solution, thereby hindering the penetration of sulfate. Meanwhile, the consumption of portlandite by the pozzolanic reaction lowered the decalcification resistance of the materials. This produced a wide area that endured the decomposition of portlandite and carbonate-AFm. Altogether, blending 30% fly ash did not improve the resistance of the material to either sulfate attacks or decalcification; blending 50% slag can effectively mitigate sulfate ingress, though decalcification may become a governing mechanism in the degradation process.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Chemical treatment effects on Schottky contacts to metalorganic chemical vapor deposited n-type N-polar GaN

In this article, we investigate the effect of different chemical treatments, such as solvents, bases, and acids, on the surface properties and electrical behavior of Schottky diodes fabricated on metalorganic chemical vapor deposition-grown, n-type, N-polar GaN. The I–V and C–V barrier heights of the as-grown Schottky diodes are found to be 0.40 eV and 0.60 eV, respectively, with an ideality factor n = 1.07. It is found that the solvent treatments neither change the surface nor the electrical performance of the Schottky diodes, as expected. However, the treatments by the alkaline photolithography developer and acid—the latter of which is often used to clean the surface of Ga-polar GaN films prior to metal contact deposition—degrade the performance of N-polar GaN. These base and acid treatments severely roughen the surface by creating triangular/hexagonal crystallographic facets. The I–V and C–V barrier heights of these base- and acid-treated diodes are increased to 0.63 eV and 1.00 eV, respectively, with ideality factor values n < 1.2. X-ray photoelectron spectroscopy studies indicate that base- and acid-treated surfaces have lower oxygen content as compared to the as-grown sample surface. It is understood that the increment in the barrier height for base- and acid-treated diodes could be due to the change in polarity, from N-polar to semi-polar/non-polar, on these crystallographic features. All these results demonstrate that, unlike for Ga-polar GaN, the N-polar GaN surface is highly reactive to bases and acids.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2012

Electric Propulsion Induced Secondary Mass Spectroscopy

A document highlights a means to complement remote spectroscopy while also providing in situ surface samples without a landed system. Historically, most compositional analysis of small body surfaces has been done remotely by analyzing reflection or nuclear spectra. However, neither provides direct measurement that can unambiguously constrain the global surface composition and most importantly, the nature of trace composition and second-phase impurities. Recently, missions such as Deep Space 1 and Dawn have utilized electric propulsion (EP) accelerated, high-energy collimated beam of Xe+ ions to propel deep space missions to their target bodies. The energies of the Xe+ are sufficient to cause sputtering interactions, which eject material from the top microns of a targeted surface. Using a mass spectrometer, the sputtered material can be determined. The sputtering properties of EP exhaust can be used to determine detailed surface composition of atmosphereless bodies by electric propulsion induced secondary mass spectroscopy (EPI-SMS). EPI-SMS operation has three high-level requirements: EP system, mass spectrometer, and altitude of about 10 km. Approximately 1 keV Xe+ has been studied and proven to generate high sputtering yields in metallic substrates. Using these yields, first-order calculations predict that EPI-SMS will yield high signal-to-noise at altitudes greater than 10 km with both electrostatic and Hall thrusters.

Amini, Rashied↗
DOE OSTI2014

Hierarchical Na-doped cubic ZrO{sub 2} synthesis by a simple hydrothermal route and its application in biodiesel production

Hierarchical growth of cubic ZrO{sub 2} phase was successfully synthesized via a simple hydrothermal process in the presence of different surfactants (cationic, non-ionic and anionic) and sodium hydroxide. The structural and microstructural characterizations of different ZrO{sub 2} powders were performed using various techniques, such as X-ray diffraction, transmission electron microscopy, N{sub 2} adsorption–desorption, scanning electron microscopy and infrared. Results indicated that sodium addition stabilized the cubic ZrO{sub 2} phase by a Na-doping process, independently of the surfactant used. In contrast, microstructural characteristics varied as a function of the surfactant and sodium presence. In addition, water vapor (H{sub 2}O) and carbon dioxide (CO{sub 2}) sorption properties were evaluated on ZrO{sub 2} samples. Results evidenced that sample surface reactivity changed as a function of the sodium content. Finally, this surface reactivity was evaluated on the biodiesel transesterification reaction using the different synthesized samples, obtaining yields of 93%. - Graphical abstract: Hierarchical growth of cubic Na-ZrO{sub 2} phase was synthesized by hydrothermal processes in the presence of surfactants and sodium. Sodium addition stabilized the cubic phase by a Na-doping process, while the microstructural characteristics varied with surfactants. Finally, this surface reactivity was evaluated on the biodiesel transesterification reaction. - Highlights: • Cubic-ZrO{sub 2} phase was synthesized via a simple hydrothermal process. • ZrO{sub 2} structure and microstructures changed as a function of the surfactant. • Cubic-ZrO{sub 2} phase was evaluated on the biodiesel transesterification reaction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2000

Microbiological Contamination of Spacecraft

The International Space Station (ISS) Phase1 Program resulted in seven US astronauts residing aboard the Russian Space Station Mir between March 1995 and May 1998. Collaboration between U.S. and Russian scientists consisted of collection and analyses of samples from the crewmembers and the Mir and Shuttle environments before, during, and after missions that lasted from 75 to 209 days in duration. The effects of long-duration space flight on the microbial characteristics of closed life support systems and the interactions of microbes with the spacecraft environment and crewmembers were investigated. Air samples were collected using a Russian or U.S.-supplied sampler (SAS, RCS, or Burkard,) while surface samples were collected using contact slides (Hycon) or swabs. Mir recycled condensate and stored potable water sources were analyzed using the U.S.-supplied Water Experiment Kit. In-flight analysis consisted of enumeration of levels of bacteria and fungi. Amounts of microorganisms seen in the air and on surfaces were mostly within acceptability lin1its; observed temporal fluctuations in levels of microbes probably reflect changes in environmental conditions (e.g., humidity). All Mir galley hot water samples were within the standards set for Mir and the ISS. Microbial isolates were returned to Earth for identification of bacterial and fungal isolates. Crew samples (nose, throat, skin, urine, and feces) were analyzed using methods approved for the medical evaluations of Shuttle flight crews. No significant changes in crew microbiota were found during space flight or upon return relative to preflight results. Dissemination of microbes between the crew and environment was demonstrated by D A fingerprinting. Some biodegradation of spacecraft materials was observed. Accumulation of condensate allowed for the recovery of a wide range of bacteria and fungi as well as some protozoa and dust mites.

Pierson, D. L.↗
DOE OSTI2011

Combined Atomic Force Microscope-Based Topographical Imaging and Nanometer Scale Resolved Proximal Probe Thermal Desorption/Electrospray Ionization-Mass Spectrometry

Nanometer scale proximal probe thermal desorption/electrospray ionization mass spectrometry (TD/ESI-MS) was demonstrated for molecular surface sampling of caffeine from a thin film using a 30 nm diameter nano-thermal analysis (nano-TA) probe tip in an atomic force microscope (AFM) coupled via a vapor transfer line and ESI interface to a MS detection platform. Using a probe temperature of 350 C and a spot sampling time of 30 s, conical desorption craters 250 nm in diameter and 100 nm deep were created as shown through subsequent topographical imaging of the surface within the same system. Automated sampling of a 5 x 2 array of spots, with 2 m spacing between spots, and real time selective detection of the desorbed caffeine using tandem mass spectrometry was also demonstrated. Estimated from the crater volume (~2x106 nm3), only about 10 amol (2 fg) of caffeine was liberated from each thermal desorption crater in the thin film. These results illustrate a relatively simple experimental setup and means to acquire in automated fashion sub-micrometer scale spatial sampling resolution and mass spectral detection of materials amenable to TD. The ability to achieve MS-based chemical imaging with 250 nm scale spatial resolution with this system is anticipated.

atomic force microscope↗
NASA NTRS1972

Luminescence petrography of lunar samples

Light-colored metaclastic rock fragments, mainly anorthositic breccias, are dominant in the lithic clasts of rock 14321 and constitute about 25% of the Apollo 14 soils. Concentration of anorthositic breccias is less in the Apollo 15 soils, but is higher in the Front samples. The Rille edge soils are rich in basalt fragments. The Apollo 15 soils are also rich in green glasses. True anorthosites in the Hadley region were found only at the St. George Crater site. Varying degrees of metamorphism were found in the anorthositic fragments, and luminescence zonations give independent evidence of metamorphism. Compositional zoning verifies the interpretation of luminescence. Rock 14321 gives evidence of modest annealing, but the light metaclastic fragments were metamorphosed before incorporation into the rock. Reaction rimming on plagioclase results in mosaicism and preferentially affects grains. The spectral analysis of luminescence in plagioclase shows that a red-infrared emission band is present in a small fraction of plagioclase grains. Samples from trench bottoms and from beneath a large boulder were compared with surface samples. Large variations in soil composition indicate marked layering in the Apollo 15 soils.

Source record↗
NASA NTRS1981

Containerless undercooling and solidification in drop tubes

A containerless low-gravity environment, produced within a 32 m drop tube apparatus, has been used to undercool and solidify metals, alloys or glasses by eliminating crucible induced nucleation processes. Niobium droplets with diameters in the range of 2 to 5 mm have been undercooled by 525 K which corresponds to the maximum undercooling reported by Turnbull and others on fine dispersions of low melting point metals. Solidification at large undercooling resulted in single crystalline spheres with the formation of interdendritic shrinkage channels on the sample surface rather than interior shrinkage cavities. The grain refinement as observed for Ni samples undercooled and solidified in fused silica crucibles does not occur in free-falling drops of Nb. A calculated solidification speed of undercooled Nb is compared to Ni. A solidification speed of 320 m/s is found for the Nb drops. This solidification speed is greater than or comparable to the solidification speeds calculated in splat cooled samples. Thus, a drop tube apparatus can be useful in the preparation and study of high temperature metastable compounds or alloys in bulk form.

Lacy, L. L.↗
NASA NTRS2007

Visual Inspection of Surfaces

This presentation evaluates the parameters that affect visual inspection of cleanliness. Factors tested include surface reflectance, surface roughness, size of the largest particle, exposure time, inspector and distance from sample surface. It is concluded that distance predictions were not great, particularly because the distance at which contamination is seen may depend on more variables than those tested. Most parameters estimates had confidence of 95% or better, except for exposure and reflectance. Additionally, the distance at which surface is visibly contaminated decreases with increasing reflectance, roughness, and exposure. The distance at which the surface is visually contaminated increased with the largest particle size. These variables were only slightly affected the observer.

Hughes, David↗
NASA NTRS2016

The Mapping X-Ray Fluorescence Spectrometer (MAPX)

MapX will provide elemental imaging at ≤100 micron spatial resolution over 2.5 X 2.5 centimeter areas, yielding elemental chemistry at or below the scale length where many relict physical, chemical, and biological features can be imaged and interpreted in ancient rocks. MapX is a full-frame spectroscopic imager positioned on soil or regolith with touch sensors. During an analysis, an X-ray source (tube or radioisotope) bombards the sample surface with X-rays or αlpha-particles / gamma rays, resulting in sample X-ray Fluorescence (XRF). Fluoresced X-rays pass through an X-ray lens (X-ray μ-Pore Optic, "MPO") that projects a spatially resolved image of the X-rays onto a CCD. The CCD is operated in single photon counting mode so that the positions and energies of individual photons are retained. In a single analysis, several thousand frames are stored and processed. A MapX experiment provides elemental maps having a spatial resolution of ≤100 micron and quantitative XRF spectra from Regions of Interest (ROI) 2 centimers ≤ x ≤ 100 micron. ROI are compared with known rock and mineral compositions to extrapolate the data to rock types and putative mineralogies. The MapX geometry is being refined with ray-tracing simulations and with synchrotron experiments at SLAC. Source requirements are being determined through Monte Carlo modeling and experiment using XMIMSIM [1], GEANT4 [2] and PyMca [3] and a dedicated XRF test fixture. A flow-down of requirements for both tube and radioisotope sources is being developed from these experiments. In addition to Mars lander and rover missions, MapX could be used for landed science on other airless bodies (Phobos/Deimos, Comet nucleus, asteroids, the Earth's moon, and the icy satellites of the outer planets, including Europa.

Blake, David↗
DOE OSTI2026

Post-fire time series of sensor and geochemistry sample data from surface water, groundwater, precipitation, soil, and vegetation across Oak Creek watershed, Washington

This dataset supports a broader study examining wildfire impacts on hydrologic connectivity across 5 sites within the Oak Creek watershed and the resulting biogeochemical impacts. Stream sites were selected using the Advanced Terrestrial Simulator (ATS) hydrologic model to identify locations with varying groundwater contributions and hydrologic responses across different burn severity scenarios. The Retreat Fire burned from July 23 to August 2 in 2024, affecting the five study sites at varying burn severities. Each site is equipped with YSI EXO2 sondes logging sub-hourly throughout the year, and grab samples are collected approximately every six weeks. YSI sondes are used to measure temporally resolved proxies for groundwater inputs (specific conductivity) and organic matter (fluorescent dissolved organic matter; fDOM) along with basic water quality and depth. Grab samples of surface water, groundwater, and precipitation are analyzed for water stable isotopes and conductivity to understand endmembers for hydrologic mixing Grab samples of surface water, groundwater, soil water, and litter/vegetation/soil leachates are analyzed for organic matter composition measured by Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS) to understand organic matter dynamics. Game camera photos are provided in a separate data package available at https://data.ess-dive.lbl.gov/datasets/doi:10.15485/3018598. Future versions of this dataset will include time series data from YSI EXO2 sondes (fDOM, dissolved oxygen, temperature, depth, specific conductance, turbidity, pH), BaroTROLL sensors (air temperature and barometric pressure), rain gauges (precipitation), and data from the soil and vegetation samples. Because this study is ongoing, this data package will be updated regularly to include newly collected data and the additional data types. For details on how to navigate data packages generated by this project, see https://data.ess-dive.lbl.gov/portals/PNNLRiverCorridorSFA/About. In addition to a readme, this data package also includes a file-level metadata (FLMD) file that describes each file and a data dictionary (DD) that describes all column/row headers and variable definitions. This dataset is comprised of (1) a folder of field photos; (2) a folder of surface water sample data; (3) a folder of raw Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) data; (4) a data checks report; (5) file-level metadata; (6) data dictionary; (7) field metadata; (8) readme; (9) international generic sample number (IGSN) mapping file; and (10) field protocols. The sample data subfolder contains (1) dissolved organic carbon (DOC, measured as non-purgeable organic carbon, NPOC) data and averages; (2) total dissolved nitrogen data and averages; (3) stable water isotopes and averages; (4) methods codes; (5) FTICR-MS methods; and (15) a subfolder of 9.4 Tesla (9.4T) FTICR-MS data. This folder contains the processed data and three subfolders, one containing the .xml files, one containing the water CoreMS output files, and the other containing instructions and scripts for processing the files in CoreMS (https://github.com/EMSL-Computing/CoreMS). All files are .csv, .pdf, .R, .xml, .d, .html, .Rmd, .py, .cal, .json, .jpg, .jpeg, .png, .mov, or .mp4.

Biogeochemistry↗