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At least 973 records · Page 54

All sources NASA NTRS DOE OSTI

DOE OSTI2024

Predicting the Rate of Degradation Related to Oxygen Electrode Delamination in Solid Oxide-Ion Electrolyzers

One of the leading causes for the performance degradation in H 2 -producing solid oxide electrolytic cells (SOECs) is the gradual delamination of oxygen electrode (OE) from the electrolyte under a strong anodic polarization. Identification of the key factor that controls the rate of OE delamination is of paramount importance to achieve long-term stable operation of SOECs. Here we show from thousands of hours of testing data that the exchange current density (i°) of OE can be leveraged as a predictor for the rate of delamination. To obtain i°, we apply DC-biased electrochemical impedance spectroscopy on a three-electrode symmetrical cell to measure polarization resistance (R p ) of OE as a function of current density (i) and time (t). The collected R p -i-t raw data are then converted to overpotential ( η )-i-t, from which i° is extracted from the “low-field” approximation. An analytical relationship between i° and time-to-delamination (TTD) is further established from the established i°-i-t relationship. We show that under a constant anodic polarization current density i, the greater the ratio i/i°, the faster the delamination. Therefore, we conclude that the exchange current density of an OE, i°, can be used to predict the rate of OE degradation in solid oxide-ion electrolyzers.

25 ENERGY STORAGE↗

DOE OSTI2024

Reliability and Durability Testing of Glass Ceramic Seals for Praxair’s Oxygen Transport Membranes

Praxair has been developing Oxygen Transport Membrane (OTM) systems for the efficient conversion of natural gas to syngas which can subsequently be used in chemical synthesis, generation of industrial gases (H2, CO) or synthesis of liquid fuels. One of the technical barriers for commercialization of this technology is the reliability of key components of OTM systems – Seals and Membranes. Praxair has been testing these components at the process conditions expected for commercial systems. However, long-term durability data is currently limited and is not sufficiently available to make well informed predictions of OTM reliability which represents one of the major risks that could prevent the technology from being fully commercialized. Pacific Northwest National Laboratory (PNNL) has been developing high temperature seals and ceramic membranes for applications similar to OTM systems such as Solid Oxide Fuel Cells. The goal of the cooperative development between Praxair and PNNL is to generate long-term data such that there is sufficient confidence in the OTM seal and membrane reliability predictions to enable the process technology to be fully commercialized.

03 NATURAL GAS↗

DOE OSTI2025

Utilization of Carbon Supply Chain Wastes and Byproducts to Manufacture Graphite for Energy Storage Applications

This project explored how coal and waste coal can be transformed into high-value graphite used in batteries for electric vehicles and power grids. A manufacturing technique that converts coal into carbon foam and subsequently graphite was developed and refined to improve the thermal and mechanical properties of the resulting materials. Cost-effectiveness and environmental impacts were also evaluated. Coal-derived graphite, especially when processed at high temperatures, was shown to perform comparably to commercial graphite in battery tests. Advanced computer simulations were used to model battery behavior and predict long-term performance, demonstrating that coal-based graphite has the potential to support electric vehicle deployment while reducing reliance on imported materials. This work offers a promising pathway for cleaner energy storage solutions and creates economic opportunities for coal-reliant communities by generating new uses for mining byproducts.

01 COAL, LIGNITE, AND PEAT↗

DOE OSTI2026

Photon Detection System Calibration for DUNE

Photon Detection System Calibration for DUNE Not scheduled 20m Conference Center (University of California, Irvine) Poster New Technologies for Neutrino Physics Poster session Speaker Denis Torres (South Dakota School of Mines and Technology) Description The Deep Underground Neutrino Experiment (DUNE) is a long baseline neutrino oscillation experiment that relies on a precise Photon Detection System (PDS) to provide accurate timing information, enhance sensitivity to low-energy and non-beam events, and support detector performance studies in liquid argon time projection chambers. Achieving these goals requires a well-understood and stable optical calibration strategy that operates reliably under cryogenic conditions. In this poster, I will present PDS calibration studies performed in ProtoDUNE, focusing on the characterization of the ultraviolet (UV) light calibration system and key optical components in the light-delivery chain. I will discuss measurements of optical fiber transmission, SMA-to-SMA connector and feedthrough interface losses, and diffuser assemblies, emphasizing wavelength dependence, attenuation, and performance under cryogenic thermal cycling and stability tests. These studies provide quantitative inputs for understanding light transport, uniformity, and long-term reliability of the PDS in large-scale liquid argon detectors, and they directly inform calibration strategies for the DUNE Far Detector.

Torres Muñoz, Denis [South Dakota Sch. Mines Tech.↗

DOE OSTI2022

Detecting Coastal Wetland Degradation by Combining Remote Sensing and Hydrologic Modeling

Sea-level rise and climate change stresses pose increasing threats to coastal wetlands that are vital to wildlife habitats, carbon sequestration, water supply, and other ecosystem services with global significance. However, existing studies are limited in individual sites, and large-scale mapping of coastal wetland degradation patterns over a long period is rare. Our study developed a new framework to detect spatial and temporal patterns of coastal wetland degradation by analyzing fine-scale, long-term remotely sensed Normalized Difference Vegetation Index (NDVI) data. Then, this framework was tested to track the degradation of coastal wetlands at the Alligator River National Wildlife Refuge (ARNWR) in North Carolina, United States, during the period from 1995 to 2019. We identified six types of coastal wetland degradation in the study area. Most of the detected degradation was located within 2 km from the shoreline and occurred in the past five years. Further, we used a state-of-the-art coastal hydrologic model, PIHM-Wetland, to investigate key hydrologic processes/variables that control the coastal wetland degradation. The temporal and spatial distributions of simulated coastal flooding and saltwater intrusion confirmed the location and timing of wetland degradation detected by remote sensing. The combined method also quantified the possible critical thresholds of water tables for wetland degradation. The remote sensing–hydrologic model integrated scheme proposed in this study provides a new tool for detecting and understanding coastal wetland degradation mechanisms. Our study approach can also be extended to other coastal wetland regions to understand how climate change and sea-level rise impact wetland transformations.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2024

2024 NSUF User Development Workshop on Irradiation Testing

Monday, May 20 – Thursday, May 23, 2024 at Center for Advanced Energy Studies at Idaho National Laboratory, Idaho Falls, Idaho. This pilot workshop was hosted to expand the NSUF user community and introduce irradiation testing of nuclear fuel and materials to new researchers, and to build long-term relationships between the NSUF program office, NSUF partner facilities, and NSUF university-affiliated users to provide better utilization of NSUF resources in addressing United States energy challenges.

Starks, Alexis↗

NASA NTRS1971

The development of autoclave processable, thermally stable adhesives for titanium alloy and graphite composite structures

The A-type polyimide adhesive resin P11B was modified by use of mixed diamines (thio-dianiline and meta phenylene diamine) which provided the desired autoclave processability. This new resin was termed P11BA. It was shown that copolymeric blends of P11BA and Amoco AI-1137 amide-imide resin provided improved adhesive properties when autoclave processed over the properties obtained previously by press bonding with P11B based copolymeric blended adhesives. Properties of bonded assemblies are presented for long-term aging at both elevated and low temperatures, and also stress-rupture tests at elevated temperature.

Vaughan, R. W.↗

NASA NTRS1975

Advanced water iodinating system

Potable water stores aboard manned spacecraft must remain sterile. Suitable sterilization techniques are needed to prevent microbial growth. The development of an advanced water iodinating system for possible application to the shuttle orbiter and other advanced spacecraft, is considered. The AWIS provides a means of automatically dispensing iodine and controlling iodination levels in potable water stores. In a recirculation mode test, simulating application of the AWIS to a water management system of a long term six man capacity space mission, noniodinated feed water flowing at 32.2 cu cm min was iodinated to 5 + or - ppm concentrations after it was mixed with previously iodinated water recirculating through a potable water storage tank. Also, the AWIS was used to successfully demonstrate its capability to maintain potable water at a desired I2 concentration level while circulating through the water storage tank, but without the addition of noniodinated water.

Davenport, R. J.↗

NASA NTRS1978

Internally and externally caused climate change

A numerical climate model is used to simulate climate change forced only by random fluctuations of the atmospheric heat transport. This short-term natural variability of the atmosphere is shown to be a possible 'cause' not only of the variability of the annual world average temperature about its mean, but also long-term excursions from the mean. Various external causes of climate change are also tested with the model and the results compared with observations for the past 100 years. Volcanic dust is shown to have been an important cause of climate change, while the effects of sunspot-related solar constant variation and anthropogenic forcing are not evident.

Robock, A.↗

NASA NTRS1983

Environmental effects and viscoelastic behavior of laminated graphite/epoxy composites

Primarily because of the polymeric matrix, graphite/epoxy composites are viscoelastic materials which exhibit creep and delayed failures. Guided by the time-temperature superposition principle, the authors are developing accelerated characterization techniques to predict the long term compliance behavior and creep rupture strength of composite materials based on short term tests at elevated temperatures. The effect of a post-cure cycle on the compliance and creep rupture strength of composite materials is discussed. The Zhurkov type failure law is applied to experimental creep rupture data of a typical laminate and is shown to correlate the data. A beneficial mechanical strengthening effect is described which significantly affects the failure strengths of specimens which have been under creep loading for a period of time. This aging effect is reversible if the specimen is allowed to recover before being loaded to failure. Other environmental aspects of composite materials are also reviewed.

Dillard, D. A.↗

NASA NTRS1988

Constructing Gloved wings for aerodynamic studies

Recently, two aircraft from the Dryden Flight Research Facility were used in the general study of natural laminar flow (NLF). The first, an F-14A aircraft on short-term loan from the Navy, was used to investigate transonic natural laminar flow. The second, an F-15A aircraft on long-term loan from the Air Force, was used to examine supersonic NLF. These tests were follow-on experiments to the NASA F-111 NLF experiment conducted in 1979. Both wings of the F-14A were gloved, in a two-phased experiment, with full-span(upper surface only) airfoil shapes constructed primarily of fiberglass, foam, and resin. A small section of the F-15A right wing was gloved in a similar manner. Each glove incorporated provisions for instrumentation to measure surface pressure distributions. The F-14A gloves also had provisions for instrumentation to measure boundary layer profiles, acoustic environments, and surface pitot pressures. Discussions of the techniques used to construct the gloves and to incorporate the required instrumentation are presented.

Bohn-Meyer, Marta R.↗

NASA NTRS1994

Kinetic Study of Methyl Acetate Oxidation in a Pt/Al2O3 Fixed-Bed Reactor

To support technology development for future long-term missions, a metabolic simulator will be used in a closed chamber to test the functions of a Controlled Ecological Life Support System (CELSS). Methyl acetate (MA) was selected as the fuel because its metabolic respiratory quotient is near that of humans. A kinetic study of the catalytic oxidation of MA over Pt/Al203 was then conducted to support the design and operation of the simulator. Kinetic data were obtained as a conversion percentage of MA versus retention time. The reaction was studied at one atmosphere and temperatures from 220 to 340 deg. C. The inlet MA concentration was varied from 100 to 2000 ppm with retention times from 0.01 to 10 sec. A first-order rate law and a Langmuir-Hinshelwood rate equation were tested by nonlinear regression of the kinetic data to estimate rate constants in the rate law. Regression results of the L-H equation explain the kinetic data better than the results of the first-order rate law. A Taguchi experimental design was used to study the effects of temperature, retention time, and concentrations of MA, CO2, and O2 on the conversion of MA. Results indicate that temperature has greatest effect, followed by retention time, and finally MA concentration. It was further determined that the effects of CO2 and O2 concentrations, and the cross effects, are negligible.

Hoy, Michael↗

NASA NTRS2000

Steady State Vacuum Ultraviolet Exposure Facility With Automated Calibration Capability

NASA Glenn Research Center at Lewis Field designed and developed a steady state vacuum ultraviolet automated (SSVUVa) facility with in situ VUV intensity calibration capability. The automated feature enables a constant accelerated VUV radiation exposure over long periods of testing without breaking vacuum. This test facility is designed to simultaneously accommodate four isolated radiation exposure tests within the SSVUVa vacuum chamber. Computer-control of the facility for long, term continuous operation also provides control and recording of thermocouple temperatures, periodic recording of VUV lamp intensity, and monitoring of vacuum facility status. This paper discusses the design and capabilities of the SSVUVa facility.

Stueber, Thomas J.↗

NASA NTRS2003

Stirling Convertor Technologies Being Developed for a Stirling Radioisotope Generator

The Department of Energy, Lockheed Martin, Stirling Technology Company (STC), and the NASA Glenn Research Center are developing a high-efficiency Stirling Radioisotope Generator (SRG) for NASA space science missions. The SRG is being developed for multimission use, including providing electric power for unmanned Mars rovers and deep space missions. On Mars, rovers with SRGs would be used for missions that might not be able to use photovoltaic power systems, such as exploration at high Martian latitudes and missions of long duration. The projected SRG system efficiency of 23 percent will reduce the required amount of radioisotope by a factor of 4 or more in comparison to currently used Radioisotope Thermoelectric Generators. The Department of Energy recently named Lockheed Martin as the system integration contractor. Lockheed Martin has begun to develop the SRG engineering unit under contract to the Department of Energy, and has contract options to develop the qualification unit and the first flight units. The developers expect the SRG to produce about 114 Wdc at the beginning of mission, using two opposed Stirling convertors and two General Purpose Heat Source modules. STC previously developed the Stirling convertor under contract to the Department of Energy and is now providing further development as a subcontractor to Lockheed Martin. Glenn is conducting an in-house technology project to assist in developing the convertor for space qualification and mission implementation. A key milestone was recently reached with the accumulation of 12 000 hr of long-term aging on two types of neodymium-iron boron permanent magnets. These tests are characterizing any possible aging in the strength or demagnetization resistance of the magnets used in the linear alternator. Preparations are underway for a thermal/vacuum system demonstration and unattended operation during endurance testing of the 55-We Technology Demonstration Convertors. In addition, Glenn is developing a charging system for the convertors to ensure clean fills of the helium working fluid and to monitor levels of any possible contaminants at different test intervals. Possible oxidation effects depend on the level of any oxygen contamination-regenerator materials and displacer radiation shields are now being evaluated for possible oxidation effects.

Thieme, Lanny G.↗

NASA NTRS2008

Aspect-Oriented Monitoring of C Programs

The paper presents current work on extending ASPECTC with state machines, resulting in a framework for aspect-oriented monitoring of C programs. Such a framework can be used for testing purposes, or it can be part of a fault protection strategy. The long term goal is to explore the synergy between the fields of runtime verification, focused on program monitoring, and aspect-oriented programming, focused on more general program development issues. The work is inspired by the observation that most work in this direction has been done for JAVA, partly due to the lack of easily accessible extensible compiler frameworks for C. The work is performed using the SILVER extensible attribute grammar compiler framework, in which C has been defined as a host language. Our work consists of extending C with ASPECTC, and subsequently to extend ASPECTC with state machines.

runtime verifications↗

NASA NTRS2012

Science Opportunities with the Near-IR Camera (NIRCam) on the James Webb Space Telescope (JWST)

The Near-Infrared Camera (NIRCam) on the James Webb Space Telescope (JWST) offers revolutionary gains in sensitivity throughout the 1-5 micrometer region. NIRCam will enable great advances in all areas of astrophysics, from the composition of objects in our own Kuiper Belt and the physical properties of planets orbiting nearby stars to the formation of stars and the detection of the youngest galaxies in the Universe. NIRCam also plays an important role in initial alignment of JWST and the long term maintenance of its image quality. NIRCam is presently undergoing instrument Integration and Test in preparation for delivery to the JWST project. Key near-term milestones include the completion of cryogenic testing of the entire instrument; demonstration of scientific and wavefront sensing performance requirements; testing of replacement H2RG detectors arrays; and an analysis of coronagraphic performance in light of measured telescope wavefront characteristics. This paper summarizes the performance of NIRCam, the scientific and education/outreach goals of the science team, and some results of the on-going testing program.

solar system↗

NASA NTRS2015

Thioaptamer Diagnostic System (TDS)

AM Biotechnologies, LLC, in partnership with Sandia National Laboratories, has developed a diagnostic device that quickly detects sampled biomarkers. The TDS quickly quantifies clinically relevant biomarkers using only microliters of a single sample. The system combines ambient-stable, long shelf-life affinity assays with handheld, microfluidic gel electrophoresis affinity assay quantification technology. The TDS is easy to use, operates in microgravity, and permits simultaneous quantification of 32 biomarkers. In Phase I of the project, the partners demonstrated that a thioaptamer assay used in the microfluidic instrument could quantify a specific biomarker in serum in the low nanomolar range. The team also identified novel affinity agents to bone-specific alkaline phosphatase (BAP) and demonstrated their ability to detect BAP with the microfluidic instrument. In Phase II, AM Biotech expanded the number of ambient affinity agents and demonstrated a TDS prototype. In the long term, the clinical version of the TDS will provide a robust, flight-tested diagnostic capability for space exploration missions.

Yang, Xianbin↗

NASA NTRS2017

VIIP 2017 Clinical Update

INTRODUCTION: NASA's Space Medicine community knowledge regarding the "Vision Impairment Intracranial Pressure", or VIIP.has been evolving over time.. Various measures of occupational health related to this condition had to be determined and then plans/processes put into place. The most robust of these processes were inititated in 2010. This presentation will provide a clinic update of the astronaut occupational health data related to VIIP. METHODS: NASA and its international partners require its astronauts to undergo routine health measures deemed important to monitoring VIIP. The concern is that the spaceflight environment aboard ISS could cause some astronauts to have physiologic changes detrimental to either ongoing mission operations or long-term health related to the ocular system and possibly the CNS. Specific medical tests include but are not limited to brain/orbit MRI (NASA unique protocol), OCT, fundoscopy and ocular ultrasound. Measures are taken prior to spaceflight, in-flight and post-flight. Measures to be reported include incidence of disc edema, globe flattening, choroidal folds, ONSD and change in refractive error. RESULTS: 73 ISS astronauts have been evaluated at least partially for VIIP related measures. Of these individuals, approximately 1 in 7 have experienced disc edema. The prevalence of the other findings is more complicated as the medical testing has changed over time. Overall, 26 separate individuals have experienced at least one of the findings NASA has associated with VIIP Another confounding factor is most of the astronauts have prior spaceflight experience at the time of the "pre-flight" testing. DISCUSSION: In 2010 NASA and its US operating segment (USOS) partners (CSA, ESA and JAXA) began routine occupational monitoring and data collection for most VIIP related changes. Interpretation of that data is extremely challenging for several reasons. For example, the determination of disc edema is the most complete finding as we have had highly qualified optometrists routinely and competently performing post-flight funduscopic exams for the entirety of the ISS program. Yet in 2013 NASA added OCT to our in-flight suite of eye exams. Shortly after routine screening with the OCT, a new term appeared within VIIP vernacular - "subclinical disc edema". OCT has much greater ability to measure change within the retina and provides significantly more data to analyze, understand and communicate out. Communicating VIIP data clearly adds even more challenge. Historically we've reported data per eye and not necessarily per person. This has led to difficulty in understanding how many individuals have experienced "VIIP" within the aerospace medicine community. The presenter will attempt to provide clear and concise communication of VIIP findings.

Tarver, William↗