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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 1,063 records · Page 59
All sourcesNASA NTRSDOE OSTI
NASA NTRS2010

Resonant difference-frequency atomic force ultrasonic microscope

A scanning probe microscope and methodology called resonant difference-frequency atomic force ultrasonic microscopy (RDF-AFUM), employs an ultrasonic wave launched from the bottom of a sample while the cantilever of an atomic force microscope, driven at a frequency differing from the ultrasonic frequency by one of the contact resonance frequencies of the cantilever, engages the sample top surface. The nonlinear mixing of the oscillating cantilever and the ultrasonic wave in the region defined by the cantilever tip-sample surface interaction force generates difference-frequency oscillations at the cantilever contact resonance. The resonance-enhanced difference-frequency signals are used to create images of nanoscale near-surface and subsurface features.

Cantrell, John H.↗
NASA NTRS2017

Osiris-REx Spacecraft Current Status and Forward Plans

The NASA New Frontiers OSIRIS-REx spacecraft executed a flawless launch on September 8, 2016 to begin its 23-month journey to near-Earth asteroid (101955). The primary objective of the OSIRIS-REx mission is to collect and return to Earth a pristine sample of regolith from the asteroid surface. The sampling event will occur after a two-year period of remote sensing that will ensure a high probability of successful sampling of a region on the asteroid surface having high science value and within well-defined geological context. The OSIRIS-REx instrument payload includes three high-resolution cameras (OCAMS), a visible and near-infrared spectrometer (OVIRS), a thermal imaging spectrometer (OTES), an X-ray imaging spectrometer (REXIS), and a laser altimeter (OLA). As the spacecraft follows its nominal outbound-cruise trajectory, the propulsion, power, communications, and science instruments have undergone basic functional tests, with no major issues. Outbound cruise science investigations include a search for Earth Trojan asteroids as the spacecraft approaches the Sun-Earth L4 Lagrangian point in February 2017. Additional instrument checkouts and calibrations will be carried out during the Earth gravity assist maneuver in September 2017. During the Earth-moon flyby, visual and spectral images will be acquired to validate instrument command sequences planned for Bennu remote sensing. The asteroid Bennu remote sensing campaign will yield high resolution maps of the temperature and thermal inertia, distributions of major minerals and concentrations of organic matter across the asteroid surface. A high resolution 3d shape model including local surface slopes and a high-resolution gravity field will also be determined. Together, these data will be used to generate four separate maps that will be used to select the sampling site(s). The Safety map will identify hazardous and safe operational regions on the asteroid surface. The Deliverability map will quantify the accuracy with which the navigation team can deliver the spacecraft to and from specific sites on the asteroid surface. The Sampleability map quantifies the regolith properties, providing an estimation of how much material would be sampled at different points on the surface. The final Science Value map synthesizes the chemical, mineralogical, and geological, observations to identify the areas of the asteroid surface with the highest science value. Here, priority is given to organic, water-rich regions that have been minimally altered by surface processes. Asteroid surface samples will be acquired with a touch-and-go sample acquisition system (TAGSAM) that uses high purity pressurized N2 gas to mobilize regolith into a stainless steel canister. Although the mission requirement is to collect at least 60 g of material, tests of the TAGSAM routinely exceeded 300 g of simulant in micro-gravity tests. After acquiring the sample, the spacecraft will depart Bennu in 2021 to begin its return journey, with the sample return capsule landing at the Utah Test and Training Range on September 23, 2023. The OSIRIS-REx science team will carry out a series of detailed chemical, mineralogical, isotopic, and spectral studies that will be used to determine the origin and history of Bennu and to relate high spatial resolution sample studies to the global geological context from remote sensing. The outline of the sample analysis plan is described in a companion abstract.

Messenger, Scott↗
DOE OSTI2017

Analysis of Samples Collected from the Surface of Interim Storage Canisters at Calvert Cliffs in June 2017: Revision 01.

In June 2017, dust and salt samples were collected from the surface of Spent Nuclear Fuel (SNF) dry storage canisters at the Calvert Cliffs Nuclear Power Plant. The samples were delivered to Sandia National laboratories for analysis. Two types of samples were collected: filter-backed Scotch-Brite TM pads were used to collect dry dust samples for characterization of salt and dust morphologies and distributions; and Saltsmart TM test strips were used to collect soluble salts for determining salt surface loadings per unit area. After collection, the samples were sealed into plastic sleeves for shipping. Condensation within the sleeves containing the Scotch-Brite TM samples remobilized the salts, rendering them ineffective for the intended purpose, and also led to mold growth, further compromising the samples; for these reasons, the samples were not analyzed. The SaltSmart TM samples were unaffected and were analyzed by ion chromatography for major anions and cations. The results of those analyses are presented here.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRS2011

Space Weathering Impact on Solar System Surfaces and Planetary Mission Science

We often look "through a glass, darkly" at solar system bodies with tenuous atmospheres and direct surface exposure to the local space environment. Space weathering exposure acts via universal space-surface interaction processes to produce a thin patina of outer material covering, potentially obscuring endogenic surface materials of greatest interest for understanding origins and interior evolution. Examples of obscuring exogenic layers are radiation crusts on cometary nuclei and iogenic components of sulfate hydrate deposits on the trailing hemisphere of Europa. Weathering processes include plasma ion implantation into surfaces, sputtering by charged particles and solar ultraviolet photons, photolytic chemistry driven by UV irradiation, and radiolytic chemistry evolving from products of charged particle irradiation. Regolith structure from impacts, and underlying deeper structures from internal evolution, affects efficacy of certain surface interactions, e.g. sputtering as affected by porosity and surface irradiation dosage as partly attenuated by local topographic shielding. These processes should be regarded for mission science planning as potentially enabling, e.g. since direct surface sputtering, and resultant surface-bound exospheres, can provide in-situ samples of surface composition to ion and neutral mass spectrometers on orbital spacecraft. Sample return for highest sensitivity compOSitional and structural analyses at Earth will usually be precluded by limited range of surface sampling, long times for return, and high cost. Targeted advancements in instrument technology would be more cost efficient for local remote and in-situ sample analysis. More realistic laboratory simulations, e.g. for bulk samples, are needed to interpret mission science observations of weathered surfaces. Space environment effects on mission spacecraft and science operations must also be specified and mitigated from the hourly to monthly changes in space weather and from longer term (e.g., solar cycle) evolution of space climate. Capable instrumentation on planetary missions can and should be planned to contribute to knowledge of interplanetary space environments. Evolving data system technologies such as virtual observatories should be explored for more interdisciplinary application to the science of planetary surface, atmospheric, magnetospheric, and interplanetary interactions.

Cooper, John F.↗
DOE OSTI2010

Surface characterization of Nb samples electropolished together with real superconducting rf accelerator cavities

Here, we report the results of surface characterizations of niobium (Nb) samples electropolished together with a single cell superconducting radio-frequency accelerator cavity. These witness samples were located in three regions of the cavity, namely at the equator, the iris and the beam-pipe. Auger electron spectroscopy (AES) was utilized to probe the chemical composition of the topmost four atomic layers. Scanning electron microscopy with energy dispersive X-ray for elemental analysis (SEM/EDX) was used to observe the surface topography and chemical composition at the micrometer scale. A few atomic layers of sulfur (S) were found covering the samples non-uniformly. Niobium oxide granules with a sharp geometry were observed on every sample. Some Nb-O granules appeared to also contain sulfur.

43 PARTICLE ACCELERATORS↗
DOE OSTI2012

Electrical and optical characteristics of surface treated ZnO nanotubes

Highlights: ► ZnO nanotubes were formed onto an ITO glass and were surface treated. ► Photoluminescence and fluorescence imaging for ZnO nanotubes showed blue emission. ► Surface treated samples that showed green emissions. ► Lifetime measurements showed higher excitonic times in surface treated samples. ► Conductance measurements showed significant improvement for the treated samples. -- Abstract: Vertical ZnO nanotubes were electrochemically deposited onto an indium doped tin oxide glass substrate. These nanotubes were surface treated with zinc acetate and annealed at 450 °C, resulting in a nanotubes/nanoparticles composite layer. Scanning electron microscopy of the surface treated samples showed nanoparticles been dispersed uniformly along the ZnO tubular matrix, which was confirmed by X-ray diffractrometry. Photoluminescence and fluorescence microscopy showed untreated ZnO nanotubes exhibiting blue emission, while the treated samples exhibited green emissions. Ultra-violet spectroscopy of treated samples revealed lower band gap values compare to their untreated counterparts. Lifetime measurements showed higher excitonic lifetimes in treated samples. Conductance studies using atomic force microscopy showed significant improvement in the conductance values for the treated samples. A significant increase in photocurrent was observed in treated samples when used as photo-anodes in dye sensitized solar cells.

36 MATERIALS SCIENCE↗
NASA NTRS2007

Nanoscale Subsurface Imaging of Nanocomposites via Resonant Difference-Frequency Atomic Force Ultrasonic Microscopy

A scanning probe microscope methodology, called resonant difference-frequency atomic force ultrasonic microscopy (RDF-AFUM), has been developed. The method employs an ultrasonic wave launched from the bottom of a sample while the cantilever of an atomic force microscope engages the sample top surface. The cantilever is driven at a frequency differing from the ultrasonic frequency by one of the contact resonance frequencies of the cantilever. The nonlinear mixing of the oscillating cantilever and the ultrasonic wave at the sample surface generates difference-frequency oscillations at the cantilever contact resonance. The resonance-enhanced difference-frequency signals are used to create amplitude and phase-generated images of nanoscale near-surface and subsurface features. RDF-AFUM phase images of LaRC-CP2 polyimide polymer containing embedded nanostructures are presented. A RDF-AFUM micrograph of a 12.7 micrometer thick film of LaRC-CP2 containing a monolayer of gold nanoparticles embedded 7 micrometers below the specimen surface reveals the occurrence of contiguous amorphous and crystalline phases within the bulk of the polymer and a preferential growth of the crystalline phase in the vicinity of the gold nanoparticles. A RDF-AFUM micrograph of LaRC-CP2 film containing randomly dispersed carbon nanotubes reveals the growth of an interphase region at certain nanotube-polymer interfaces.

Cantrell, Sean A.↗
DOE OSTI2014

Microwave magnetic dynamics in highly conducting magnetic nanostructures

We performed low-noise broadband microstrip ferromagnetic resonance (FMR) measurements of the resonant modes of an array of metallic ferromagnetic nanostripes. In addition to a strong signal of the fundamental mode, we observed up to five weak-amplitude peaks in the field-resolved FMR traces, depending on the frequency. These higher-order absorption peaks have been theoretically identified as due to resonant excitation of odd and even standing spin waves across the direction of confinement in array plane (i.e., across the stripe width). The theory we developed suggests that the odd modes become excited in the spatially uniform microwave field of the FMR setup due to the large conductivity of metals. This promotes excitation of large-amplitude eddy currents in the sample by the incident microwave magnetic field and ultimately results in excitation of these modes. Following this theory, we found that the eddy current contribution is present only for patterned materials and when the microwave magnetic field is incident on one surface of sample surface, as it is in the case of a microstrip FMR.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1976

The surface chemical composition of lunar samples and its significance for optical properties

The surface Fe, Ti, Ca, and Si concentrations in a variety of soil and rock samples from all the Apollo sites are determined using an Auger spectrometer plus a single-pass cylindrical-mirror analyzer with a standard 15-stage BeCu electron multiplier. It is found that there are no great differences between the surface and bulk concentrations of any of the four elements in the rock samples, but the surface Fe and Ti concentrations in soil samples are higher than the bulk concentrations. Results are also reported for solar-wind simulation experiments in which a pulverized rock sample was bombarded with 2-keV alpha-particles corresponding to about a 30,000-yr dose of the solar-wind proton component. These results indicate that the chemical change induced on the surface of a rock powder by positive-ion bombardment is similar to the change from bulk to surface chemical composition in lunar soil samples. A clear correlation is observed between the surface Fe concentration and albedo of the soil samples.

Gold, T.↗
NASA NTRS2022

Assessing the Sampleability of Bennu’s Surface for the OSIRIS-REx Asteroid Sample Return Mission

NASA’s first asteroid sample return mission, OSIRIS-REx, collected a sample from the surface of near-Earth asteroid Bennu in October 2020 and will deliver it to Earth in September 2023. Selecting a sample collection site on Bennu’s surface was challenging due to the surprising lack of large ponded deposits of regolith particles exclusively fine enough (≤ 2 cm diameter) to be ingested by the spacecraft’s Touch-and-Go Sample Acquisition Mechanism (TAGSAM). Here we describe the Sampleability Map of Bennu, which was constructed to aid in the selection of candidate sampling sites and to estimate the probability of collecting sufficient sample. “Sampleability” is a numeric score that expresses the compatibility of a given area’s surface properties with the sampling mechanism. The algorithm that determines sampleability is a best fit functional form to an extensive suite of laboratory testing outcomes tracking the TAGSAM performance as a function of four observable properties of the target asteroid. The algorithm and testing were designed to measure and subsequently predict TAGSAM collection amounts as a function of the minimum particle size, maximum particle size, particle size frequency distribution, and the tilt of the TAGSAM head off the surface. The sampleability algorithm operated at two general scales, consistent with the resolution and coverage of data collected during the mission. The first scale was global and evaluated nearly the full surface. Due to Bennu’s unexpected boulder coverage and lack of ponded regolith deposits, the global sampleability efforts relied heavily on additional strategies to find and characterize regions of interest based on quantifying and avoiding areas heavily covered by material too large to be collected. The second scale was site-specific and used higher-resolution data to predict collected mass at a given contact location. The rigorous sampleability assessments gave the mission confidence to select the best possible sample collection site and directly enabled successful collection of hundreds of grams of material.

Asteroid exploration↗
DOE OSTI2022

Super resolution for magneto-optical microscopy

Sub-diffraction limited magneto-optical microscopy, such as Kerr or Faraday effect microscopy, provide many advantages to fields of science and technology for measuring, or imaging, the magnetization structures and magnetization domains of materials. Disclosed is a method and system for performing sub-diffraction limited magneto-optic microscopy. The method includes positioning a microlens or microlens layer relative to a surface of a sample to image the surface of the sample, forming a photonic nanojet to probe the surface of the sample, and receiving light reflected by the surface of the sample or transmitted through the sample at an imaging sensor. The methods and associated systems and devices enable sub-diffraction limited imaging of magnetic domains at resolutions 2 to 8 times the classical diffraction limit.

te Velthuis, Suzanne Gabriëlle Everdine↗
DOE OSTI2017

Laser-driven hydrothermal process studied with excimer laser pulses

Previously, we discovered [Mariella et al., J. Appl. Phys. 114, 014904 (2013)] that modest-fluence/modest-intensity 351-nm laser pulses, with insufficient fluence/intensity to ablate rock, mineral, or concrete samples via surface vaporization, still removed the surface material from water-submerged target samples with confinement of the removed material, and then dispersed at least some of the removed material into the water as a long-lived suspension of nanoparticles. We called this new process, which appears to include the generation of larger colorless particles, “laser-driven hydrothermal processing” (LDHP) [Mariella et al., J. Appl. Phys. 114, 014904 (2013)]. Now, we report that we have studied this process using 248-nm and 193-nm laser light on submerged concrete, quartzite, and obsidian, and, even though light at these wavelengths is more strongly absorbed than at 351 nm, we found that the overall efficiency of LDHP, in terms of the mass of the target removed per Joule of laser-pulse energy, is lower with 248-nm and 193-nm laser pulses than with 351-nm laser pulses. Given that stronger absorption creates higher peak surface temperatures for comparable laser fluence and intensity, it was surprising to observe reduced efficiencies for material removal. We also measured the nascent particle-size distributions that LDHP creates in the submerging water and found that they do not display the long tail towards larger particle sizes that we had observed when there had been a multi-week delay between experiments and the date of measuring the size distributions. This is consistent with transient dissolution of the solid surface, followed by diffusion-limited kinetics of nucleation and growth of particles from the resulting thin layer of supersaturated solution at the sample surface.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Recovery Efficiency, False Negative Rate, and Limit of Detection Performance of a Validated Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates

The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in × 2 in) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on recovery efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS, 40.2% with BG) and the highest for glass (92.8% with BAS, 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG, with values increasing as concentration decreased in the range tested (0.078 to 19.375 CFU/cm2, where CFU denotes ‘colony forming units’). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended to be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results are discussed in a separate report.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1972

Laboratory and airborne techniques for measuring fluoresence of natural surfaces

Techniques are described for obtaining fluorescence spectra from samples of natural surfaces that can be used to predict spectral regions in which these surfaces would emit solar-stimulated or laser-stimulated fluorescence detectable by remote sensor. Scattered or reflected stray light caused large errors in spectrofluorometer analysis or natural sample surfaces. Most spurious light components can be eliminated by recording successive fluorescence spectra for each sample, using identical instrument settings, first with an appropriate glass or gelatin filter on the excitation side of the sample, and subsequently with the same filter on the emission side of the sample. This technique appears more accurate than any alternative technique for testing the fluorescence of natural surfaces.

Stoertz, G. E.↗
DOE OSTI2015

Recovery Efficiency, False Negative Rate, and Limit of Detection Performance of a Validated Macrofoam-Swab Sampling Method with Low Surface Concentrations of Two Bacillus anthracis Surrogates

The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target amounts (2-500 spores) to positive-control plates and test coupons (2 in. × 2 in.) of four surface materials (glass, stainless steel, vinyl tile, and plastic). Test results from cultured samples were used to evaluate the effects of surrogate, surface concentration, and surface material on recovery efficiency (RE), false negative rate (FNR), and limit of detection. For RE, surrogate and surface material had statistically significant effects, but concentration did not. Mean REs were the lowest for vinyl tile (50.8% with BAS, 40.2% with BG) and the highest for glass (92.8% with BAS, 71.4% with BG). FNR values ranged from 0 to 0.833 for BAS and 0 to 0.806 for BG, with values increasing as concentration decreased in the range tested (0.078 to 19.375 CFU/cm 2 , where CFU denotes ‘colony forming units’). Surface material also had a statistically significant effect. A FNR-concentration curve was fit for each combination of surrogate and surface material. For both surrogates, the FNR curves tended to be the lowest for glass and highest for vinyl title. The FNR curves for BG tended to be higher than for BAS at lower concentrations, especially for glass. Results using a modified Rapid Viability-Polymerase Chain Reaction (mRV-PCR) analysis method were also obtained. The mRV-PCR results and comparisons to the culture results will be discussed in a subsequent report.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2014

Learning from the past: Rare ε-Fe2O3 in the ancient black-glazed Jian (Tenmoku) wares

Ancient Jian wares are famous for their lustrous black glaze that exhibits unique colored patterns. Some striking examples include the brownish colored ‘‘Hare’s Fur’’ (HF) strips and the silvery ‘‘Oil Spot’’ (OS) patterns. Herein, we investigated the glaze surface of HF and OS samples using a variety of characterization methods. Contrary to the commonly accepted theory, we identified the presence of e-Fe2O3, a rare metastable polymorph of Fe2O3 with unique magnetic properties, in both HF and OS samples. We found that surface crystals of OS samples are up to several micrometers in size and exclusively made of e-Fe2O3. Interestingly, these e-Fe2O3 crystals on the OS sample surface are organized in a periodic two dimensional fashion. These results shed new lights on the actual mechanisms and kinetics of polymorphous transitions of Fe2O3. Deciphering technologies behind the fabrication of ancient Jian wares can thus potentially help researchers improve the e-Fe2O3 synthesis.

ARCHAEOMETRY↗
DOE OSTI2017

Process-based approach for the detection of CO2 injectate leakage

The present invention includes a method for distinguishing between a natural source of deep gas and gas leaking from a CO.sub.2 storage reservoir at a near surface formation comprising: obtaining one or more surface or near surface geological samples; measuring a CO.sub.2, an O.sub.2, a CH.sub.4, and an N.sub.2 level from the surface or near surface geological sample; determining the water vapor content at or above the surface or near surface geological samples; normalizing the gas mixture of the CO.sub.2, the O.sub.2, the CH.sub.4, the N.sub.2 and the water vapor content to 100% by volume or 1 atmospheric total pressure; determining: a ratio of CO.sub.2 versus N.sub.2; and a ratio of CO.sub.2 to N.sub.2, wherein if the ratio is greater than that produced by a natural source of deep gas CO.sub.2 or deep gas methane oxidizing to CO.sub.2, the ratio is indicative of gas leaking from a CO.sub.2 storage reservoir.

58 GEOSCIENCES↗
DOE OSTI2015

Analysis of Tank 39H (HTF-39-15-61, 62) Surface and Subsurface Supernatant Samples in Support of Corrosion Control Program

This report provides the results of analyses on Tanks 39H surface and subsurface supernatant liquid samples in support of the Corrosion Control Program. Analyses included warm acid strike preparation followed by analysis for silicon, aluminum, and sodium and water dilution preparation followed by analysis for anions. Other reported analytical results include analyses results for uranium, Pu-241 and Pu-239.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗