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NASA NTRS2012

SEVO (Space Environment Viability of Organics) Preliminary Results from Orbit

SEVO (Space Environment Viability of Organics) is one of two astrobiology experiments onboard the NASA Organism/Organics Exposure to Orbital Stresses (O/OREOS) cubesat, launched in November 2010. The satellite is still operational with nominal performance and records data on a regular basis. In the SEVO experiment, four astrobiologically relevant organic thin films are exposed to radiation in low-earth orbit, including the unfiltered solar spectrum from approximately 120 - 2600 nm. The thin films are contained in each of four separate micro-environments: an atmosphere containing CO2, a low relative humidity (approximately 2%) atmosphere, an inert atmosphere representative of interstellar/interplanetary space, and a SiO2 mineral surface to measure the effects of surface catalysis. The UV/Vis spectrum of each sample is monitored in situ, with a spectrometer onboard the satellite.

Cook, A.↗

DOE OSTI2021

Adsorption of Iodine on Metal Coupons in Humid and Dry Environments

In this study, five different metal coupons were evaluated for gaseous iodine [I2(g)] adsorption including two stainless steels (i.e., SS304 and SS316), two Inconel® alloys (i.e., 625 and 718) and pure Ni (i.e., Ni-200) within a dynamic flow-through system where temperature, iodine concentration, flow rate, atmosphere, and relative humidity were controlled. Humidity was shown to be critical to iodine adsorption on SS304 and SS316 and Ni-200 at ambient temperatures. The results presented herein suggest that a moisture mediated reaction is occurring. However, higher humidity levels decrease the adsorption, suggesting an ideal range of humidity for highest corrosion. A comparison of the five metal substrates showed the highest I2(g) adsorption in the following descending order Ni-200 > SS304 > SS316 >718>625.The 625 and 718 Inconel alloys were fairly inert to iodine adsorption under the conditions tested. Characterization by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction of the Ni-200 coupon indicates that NiI2 is formed and flakes off the surface as a black powder. The SS304 and SS316 coupons showed evidence of extensive reactions with I2(g) and formed a much more deliquescent corrosion product, which reacted with air when removed from the flow-through system for weighing on the analytical balance. These findings assist in predicting iodine adsorption behavior on a variety of metal surfaces under various conditions.

Beck, Chelsie L.↗

DOE OSTI2024

Suppressing Atmospheric Degradation of Sulfide-Based Solid Electrolytes via Ultrathin Metal Oxide Layers

Sulfide-based solid-state electrolytes (SSEs) are promising materials with superior Li-ion conductivity; however, their poor atmospheric stability limits commercial manufacturing at scale. Here, we investigate the impact of ultrathin metal oxide layers deposited via atomic layer deposition (ALD) on the stability of Li 6 PS 5 Cl (LPSCl). Al 2 O 3 layers grown directly on LPSCl particles significantly stabilize the surface chemistry and Li-ion transport properties relative to uncoated material upon exposure to both an ambient atmosphere (22% relative humidity, RH) and humidified O 2 (100% RH). Detailed investigations indicate that coatings impede the surface and bulk degradation kinetics of exposed materials, even for coatings as thin as ∼1 Å. Furthermore, this suggests that stabilization is due to more than just a physical barrier. Shifts in valence band edge positions of coated LPSCl indicate that ALD coatings alter the surface electronic structure and resulting oxidation tendency of underlying LPSCl, suggesting new avenues to improving the environmental stability of sulfide SSEs.

Atmospheric chemistry↗

DOE OSTI2021

Upper Troposphere Smoke Injection From Large Areal Fires

Abstract Large areal fires, such as those ignited following a nuclear detonation, can inject smoke into the upper troposphere and lower stratosphere. Detailed fire simulations allow for assessment of how local weather interacts with these fires and affects smoke lofting. In this study, we employ the fire simulation package in the Weather Research and Forecasting (WRF‐Fire) model, Version 4.0.1, to explore how smoke lofting from a fire burning a homogeneous fuel bed changes with varying local winds, relative humidity, and atmospheric boundary‐layer stability for two different‐sized areal fires. The presence of moisture has the greatest influence on the results by raising the altitude of lofting, while faster wind speeds dampen lofting and lower the injection height. Stably stratified conditions inhibit plume propagation compared with neutrally stratified conditions, although the impact of stability is not as strong as that of moisture and winds. These findings highlight the importance of using an appropriate atmospheric profile when simulating large fires, as the local weather can have a meaningful influence on smoke lofting.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2024

WFIP3 - RHOD Site - PNNL Surface Meteorological Suit / Raw Data

This dataset contains raw data from the WFIP3 RHOD site supplementary meteorological sensors: T/RH and barometer; 1-sec average. The supplementary meteorological suite was added to PNNL Surface Flux Station to provide independent measurements of air temperature, relative humidity, and atmospheric pressure.

17 WIND ENERGY↗

DOE OSTI2024

Surface Meteorological Station / Raw Data

17 WIND ENERGY↗

DOE OSTI2025

RHOD Site - Surface Meteorological Station / Processed Data

17 WIND ENERGY↗

NASA NTRS1971

Evaluation program for secondary spacecraft cells: Acceptance test of McDonnell-Douglas, Astropower division, 40.0 ampere hour silver-zinc cells

The development of an inorganic separator material for use in construction of 40 ampere-hour silver zinc cells is discussed. Acceptance tests were conducted to determine real quality, physical defects and ampere-hour capacity. All acceptance tests were performed at an ambient temperature of 23 to 27 C at existing relative humidity and atmospheric pressure. Of the 63 cells tested, only one failed to meet the equipment specifications.

Harkness, J. D.↗

NASA NTRS1981

Stratospheric CCN sampling program

When Mt. St. Helens produced several major eruptions in the late spring of 1980, there was a strong interest in the characterization of the cloud condensation nuclei (CCN) activity of the material that was injected into the troposphere and stratosphere. The scientific value of CCN measurements is two fold: CCN counts may be directly applied to calculations of the interaction of the aerosol (enlargement) at atmospherically-realistic relative humidities or supersaturations; and if the chemical constituency of the aerosol can be assumed, the number-versus-critical supersaturation spectrum may be converted into a dry aerosol size spectrum covering a size region not readily measured by other methods. The sampling method is described along with the instrumentation used in the experiments.

Rogers, C. F.↗

NASA NTRS1983

Friction, wear, transfer and wear surface morphology of ultra-high-molecular-weight polyethylene

Tribological studies at 25 C in a 50-percent-relative-humidity air atmosphere were conducted using hemispherically tipped 440 C HT (high temperature) stainless steel pins sliding against ultra-high-molecular-weight polyethylene (UHMWPE) disks. The results indicate that sliding speed, sliding distance, contact stress and specimen geometry can markedly affect friction, UHMWPE wear, UHMWPE transfer and the type of wear mechanisms that occur. Adhesion appears to be the predominant wear mechanism; but after long sliding distances at slow speeds, heavy ridges of transfer result which can induce fatigue-like wear on the UHMWPE disk wear track. In one instance, abrasive wear to the metallic pin was observed. This was caused by a hard particle embedded in the UHMWPE disk wear track.

Fusaro, R. L.↗

NASA NTRS1985

Friction, wear, transfer, and wear surface morphology of ultrahigh-molecular-weight polyethylene

Fusaro, R. L.↗

NASA NTRS1992

Environmental Tests Of Cesium Frequency Standards

Report describes environmental tests of cesium-beam frequency standards of United States Naval Observatory. Purpose of tests to determine effects of atmospheric temperature, relative humidity, and pressure on frequencies.

Sydnor, Richard L.↗

NASA NTRS1991

Retrieval of surface heat and moisture fluxes from slow-launched radiosondes

A feasibility experiment to determine whether the Bowden ratio (and indirectly moisture fluxes and surface heat) can be reasonably and accurately derived from thermodynamic measurements obtained from balloon-launched radiosondes is presented. This experiment was conducted during July 1988 in Tallahassee, Florida using an airsonde system and a surface radiation and energy budget station. The airsonde system consists of a balloon-launched airsonde, which measures vertical profiles of atmospheric pressure, relative humidity, temperature, and an automatic data acquisition system, which receives and records sensor output from the airsonde package. Intercomparisons were made between Bowen ratios derived from the airsonde profiles and the Bowen ratios measured directly by the energy budget station and the surface radiation.

Smith, Eric A.↗

NASA NTRS2007

Apparatus and method for centrifugation and robotic manipulation of samples

A device for centrifugation and robotic manipulation of specimen samples, including incubating eggs, and uses thereof are provided. The device may advantageously be used for the incubation of avian, reptilian or any type of vertebrate eggs. The apparatus comprises a mechanism for holding samples individually, rotating them individually, rotating them on a centrifuge collectively, injecting them individually with a fixative or other chemical reagent, and maintaining them at controlled temperature, relative humidity and atmospheric composition. The device is applicable to experiments involving entities other than eggs, such as invertebrate specimens, plants, microorganisms and molecular systems.

Vellinger, John C.↗

DOE OSTI2025

AI‐Driven Robot Enables Synthesis‐Property Relation Prediction for Metal Halide Perovskites in Humid Atmosphere

Materials Acceleration Platforms (MAPs) – also known as self-driving laboratories– present a new paradigm for materials science and promise an order of magnitude accelerated materials discovery compared to the traditional trial-and-error approach. Metal halide perovskites (MHPs) are an emerging class of materials for optoelectronic applications but are plagued by irreproducible optoelectronic quality, particularly for films fabricated in a humid atmosphere. Here, in this work, a machine learning (ML)-guided closed-loop platform is developed with a multimodal data fusion approach to predict synthesis–property relations for the optical quality of MHP thin films in relative humidities (RHs) ranging from 5–55%. The efficiency of this approach is confirmed by the fast-dropping learning rate to 2% after experimentally sampling less than 1% of the possible 5,000+ combinations. The prediction of synthesis–property relations is done by optical and imaging characterizations. In situ photoluminescence characterization revealed the origin of thin film quality variation at different RH. These insights provide an avenue for controlling the MHP crystallization by fine-tuning the synthesis parameters and RH for a given chemistry, thus lifting the need for stringent atmosphere control. The MAP enables an accelerated screening and understanding of the synthesis design space, facilitating rational synthesis recipe choice for a wide range of materials.

AI-driven robot↗

NASA NTRS2004

Measuring Humidity in the Charters of Freedom Encasements Using a Moisture Condensation Method

The relative humidity of the atmosphere in the encasements containing the U.S. Constitution Pages 1 and 4, the Declaration of Independence, and the Bill of Rights was measured to be in the range of 55% to 61%. This value is significantly higher than the presumed relative humidity between 25 to 35 %, but is consistent with the measured samples extracted from Pages 2 and 3 of the U.S. Constitution. The cooling/condensation measurement technique used at NARA on July 23, 2001, and described in this paper to measure the water vapor content of the atmosphere in the hermetically sealed encasements containing the U. S. Constitution, the Declaration of Independence, and the Bill of Rights, proved to be a powerful new measurement technique. The cooling/condensation technique developed at NASA LaRC and utilized at NARA has important applications in the non-invasive measurement of relative humidity in the atmospheres of sealed encasements and could become a standard measurement technique in this type of analysis.

Burkett, Cecil G.↗

DOE OSTI2023

Relative humidity threshold for oxygen generation by high-purity plutonium dioxides in 3013 containers

High-purity plutonium dioxide with adsorbed water in a sealed container can generate oxygen, but oxygen will not be generated in low water loading conditions. A threshold for oxygen generation has been observed in the hydrogen generation rate normalized by the specific power for high-purity plutonium dioxide. Normalized hydrogen generation rates above this threshold generate oxygen and below the threshold consume oxygen. The threshold rate is determined by the amount of water adsorbed onto the surface of the oxide. The relative humidity of the atmosphere that the oxide is in equilibrium with determines the amount of physisorbed water adsorbed on the surface. We calculate the relative humidity corresponding to the threshold rate as a function of mass and specific surface area of material stored in 3013 containers. Exceeding the calculated relative humidity may result in flammable gas mixtures of hydrogen and oxygen at some time during storage.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

NASA NTRS2000

Recent Developments and Applications of Quantum Well Infrared Photodetector Focal Plane Arrays

There are many applications that require long wavelength, large, uniform, reproducible, low cost, stable, and radiation-hard infrared (IR) focal plane arrays (FPAs). For example, the absorption lines of many gas molecules, such as ozone, water, carbon monoxide, carbon dioxide, and nitrous oxide occur in the wavelength region from 3 to 18 micron. Thus, IR imaging systems that operate in the long wavelength IR (LWIR) region (6 - 18 micron) are required in many space borne applications such as monitoring the global atmospheric temperature profiles, relative humidity profiles, cloud characteristics, and the distribution of minor constituents in the atmosphere which are being planned for future NASA Earth and planetary remote sensing systems. Due to higher radiation hardness, lower 1/f noise, and larger array size the GaAs based Quantum Well Infrared Photodetector (QWIP) FPAs are very attractive for such space borne applications compared to intrinsic narrow band gap detector arrays. In this presentation we will discuss the optimization of the detector design, material growth and processing that has culminated in realization of large format long-wavelength QWIP FPAs, portable and miniature LWIR cameras, holding forth great promise for myriad applications in 6-18 micron wavelength range in science, medicine, defense and industry. In addition, we will present some system demonstrations using broadband, two-color, and high quantum efficiency long-wavelength QWIP FPAs.

Gunapala, S. D.↗