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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Shock compression of strongly correlated oxides: A liquid-regime equation of state for cerium(IV) oxide

Here, the shock Hugoniot for full-density and porous CeO 2 was investigated in the liquid regime using ab initio molecular dynamics (AIMD) simulations with Erpenbeck's approach based on the Rankine-Hugoniot jump conditions. The phase space was sampled by carrying out NVT simulations for isotherms between 6000 and 100 000 K and densities ranging from ρ = 2.5 to 20 g/cm 3 . The impact of on-site Coulomb interaction corrections +U on the equation of state (EOS) obtained from AIMD simulations was assessed by direct comparison with results from standard density functional theory simulations. Classical molecular dynamics (CMD) simulations were also performed to model atomic-scale shock compression of larger porous CeO 2 models. Results from AIMD and CMD compression simulations compare favorably with Z-machine shock data to 525 GPa and gas-gun data to 109 GPa for porous CeO 2 samples. Using results from AIMD simulations, an accurate liquid-regime Mie-Grüneisen EOS was built for CeO 2 . In addition, a revised multiphase SESAME-type EOS was constrained using AIMD results and experimental data generated in this work. This study demonstrates the necessity of acquiring data in the porous regime to increase the reliability of existing analytical EOS models.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2019

Modification of Ceria Nanoparticles by Accelerated Electron Irradiation

The luminescence and optical properties of ceria (CeO{sub 2}) nanoparticles irradiated by accelerated electrons with an energy of 10 MeV are investigated in this work. CeO{sub 2} nanoparticles are prepared by the pulse electron evaporation of a ceramic target with vapor condensation of the evaporated material in a low-pressure gas on a NANOBIM-2 installation. The irradiation of CeO{sub 2} nanopowders is found to cause the degradation of their luminescence and optical characteristics. The irradiation of a final aqueous suspension leads to the shift of a photoluminescence band toward the long wave range spectral range in comparison with the irradiation of a nanopowder. The catalytic-like behavior of CeO{sub 2} nanoparticles interacting with hydrogen peroxide is analyzed, as well. Nanoparticles modified by the electron beam exhibit the deterioration of their enzyme-like activity.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2015

Characterization of swift heavy ion irradiation damage in ceria

We have examined microstructural evolution in irradiated ceria (CeO2) using swift heavy ion irradiation, electron microscopy, and atomistic simulation. CeO2, a UO2 fuel surrogate, was irradiated with gold ions at an energy of 1 GeV to fluences up to 1x1014 ions/cm2. Transmission electron microscopy accompanied by electron energy loss spectroscopy showed that the ion tracks were of similar size at all fluences, and that there was no chemical change in the ion track core. Classical molecular dynamics simulations of thermal spikes in CeO2 with energy deposition of 12 and 36 keV/nm show damage consisting of isolated point defects at the lower energy and defect clusters at 36 keV/nm, with no amorphization at either energy. Inferences are drawn from modeling about density changes in the ion track and the formation of interstitial loops that shed light on features observed by electron microscopy of swift heavy ion irradiated ceria.

Yablinsky, Clarissa↗
DOE OSTI2018

Reducing Energy Burden with Solar: Colorado's Strategy and Roadmap for States

The Colorado Energy Office (CEO) recently implemented a multi-pronged strategy to reduce energy burden for low-income (LI) Colorado residents through the deployment of solar electricity generation. Due to these efforts, approximately 20 MW of photovoltaic (PV) solar may be deployed in Colorado by the end of 2019 specifically for low-income households. Relying on interviews with ten subject-matter experts and other research, this report outlines the details of the CEO strategy including why the agency pursued this strategy, how it was carried out, and lessons learned from implementation. Though CEO's strategy is unique and tailored to the needs of Colorado, it is possible that other states might learn from CEO's experiences when designing their own LI strategies. As a result, the report concludes by outlining six primary steps for designing a comprehensive low-income solar strategy.

14 SOLAR ENERGY↗
DOE OSTI2020

Implementing an aerosol dynamic shape factor for cerium oxide powder

The shape factor (X B ) of bulk powder CeO 2 (cerium oxide) particles is estimated to be X B = 1.34 (dimensionless). This is defined in relation to the measured aerated bulk density (0.91 g cm -3 , Hosokawa Micron, Summit NJ, 2018) of the CeO 2 powder. This information is used to determine the RRF (respirable release factor), and other parameters during drop test experiments of nuclear material storage containers at Los Alamos National Laboratory. The calculation is based on an experimental shape factor (X P = 2.66 dimensionless) for CeO 2 particles of the same (chain aggregate) morphology studied by other researchers. In that work, the shape factor was defined in terms of the maximum possible (compacted) density of CeO 2 material (7.13 g cm -3 ).

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2024

Concentrated solar thermal fuels production by electric field enhanced two step gas splitting (Final Technical Report)

Solar thermochemical CO 2 splitting (STCS) is plagued by high solar field costs due to the extraordinarily high temperatures (~1500 °C) required. In STCS, a reduction/oxidation active material, CeO 2 , is thermally reduced to CeO 2-δ generating O2 at ~1500 °C; then CeO 2-δ is re-oxidized by CO 2 to re-form CeO 2 and CO, a precursor to liquid fuels. Before this project, there were no known methods to decrease the reduction temperature while maintaining high conversion of the CO 2 to CO; thus, projected solar thermal CO costs had stagnated.

10 SYNTHETIC FUELS↗
NASA NTRS2004

Overview of NASA's Earth Science Data Systems

For over the last 15 years, NASA's Earth Science Enterprise (ESE) has devoted a tremendous effort to design and build the Earth Observing System (EOS) Data and Information System (EOSDIS) to acquire, process, archive and distribute the data of the EOS series of satellites and other ESE missions and field programs. The development of EOSDIS began with an early prototype to support NASA data from heritage missions and progressed through a formal development process to today's system that supports the data from multiple missions including Landsat 7, Terra, Aqua, SORCE and ICESat. The system is deployed at multiple Distributed Active Archive Centers (DAACs) and its current holdings are approximately 4.5 petabytes. The current set of unique users requesting EOS data and information products exceeds 2 million. While EOSDIS has been the centerpiece of NASA's Earth Science Data Systems, other initiatives have augmented the services of EOSDIS and have impacted its evolution and the future directions of data systems within the ESE. ESDIS had an active prototyping effort and has continued to be involved in the activities of the Earth Science Technology Office (ESTO). In response to concerns from the science community that EOSDIS was too large and monolithic, the ESE initiated the Earth Science Information Partners (ESP) Federation Experiment that funded a series of projects to develop specialized products and services to support Earth science research and applications. Last year, the enterprise made 41 awards to successful proposals to the Research, Education and Applications Solutions Network (REASON) Cooperative Agreement Notice to continue and extend the ESP activity. The ESE has also sponsored a formulation activity called the Strategy for the Evolution of ESE Data Systems (SEEDS) to develop approaches and decision support processes for the management of the collection of data system and service providers of the enterprise. Throughout the development of its earth science data systems, NASA has had an active collaboration with a number of interagency and international partners. One of the mechanisms that has been extremely helpful in initiating and promoting this collaboration has been NASA's participation in the Committee on Earth Observation Satellites (CEOS) and its Working Group on Information Systems and Services (WGISS). The CEOS members, working together, have implemented an International Directory Network that enables users to locate collections of earth science data held by the international community and an International Catalog System to search and order specific data products. CEOS WGISS has also promoted the international interest in the Open GIS Consortium s specifications that further advance the access and use of geospatial data and the interoperation of GTS components. These are just a few highlights of the benefits that member agencies gain from CEOS participation.

McDonald, Kenneth↗
NASA NTRS2006

Meeting Report: Long Term Monitoring of Global Vegetation using Moderate Resolution Satellites

The international community has long recognized the need to coordinate observations of Earth from space. In 1984, this situation provided the impetus for creating the Committee on Earth Observation Satellites (CEOS), an international coordinating mechanism charged with coordinating international civil spaceborne missions designed to observe and study planet Earth. Within CEOS, its Working Group on Calibration and Validation (WGCV) is tasked with coordinating satellite-based global observations of vegetation. Currently, several international organizations are focusing on the requirements for Earth observation from space to address key science questions and societal benefits related to our terrestrial environment. The Global Vegetation Workshop, sponsored by the WGCV and held in Missoula, Montana, 7-10 August, 2006, was organized to establish a framework to understand the inter-relationships among multiple, global vegetation products and identify opportunities for: 1) Increasing knowledge through combined products, 2) Realizing efficiency by avoiding redundancy, and 3) Developing near- and long-term plans to avoid gaps in our understanding of critical global vegetation information. The Global Vegetation Workshop brought together 135 researchers from 25 states and 14 countries to advance these themes and formulate recommendations for CEOS members and the Global Earth Observation System of Systems (GEOSS). The eighteen oral presentations and most of the 74 posters presented at the meeting can be downloaded from the meeting website (www.ntsg.umt.edu/VEGMTG/). Meeting attendees were given a copy of the July 2006 IEEE Transactions on Geoscience and Remote Sensing Special Issue on Global Land Product Validation, coordinated by the CEOS Working Group on Calibration and Validation (WGCV). This issue contains 29 articles focusing on validation products from several of the sensors discussed during the workshop.

Morisette, Jeffrey↗
NASA NTRS2007

The CEOS/GEO Constellation Concept

The Constellation concept was first proposed during a discussion at the 19th CEOS Plenary, in London, in November 2005. The first Paper of the Constellation Concept was presented at the CEOS Strategic Implementation Team meeting (SIT-18), in Frascati, in March 2006, and strongly endorsed by the CEOS Principals. The concept attempts to provide agencies with tools for implementation of the elements that have been previously discussed in international forums (GEO Work Plan, GCOS Implementation Plan). This provides a solid foundation from the community providing requirements. Though agency spending is governed by national requirements, CEOS seeks synergies among member agency programs to fulfil GEOSS requirements, defining guidelines and standards to help agencies to determine from the outset what can be achieved. The constellations concept will allow the development of a commonalties approach among different agencies. At the heart of the application of the Constellations concept is the definition of a series of standards (specific to each Constellation) - required to be satisfied for any mission to be included in the constellation - and a process of recognition/acceptance, whereby an agency applies to SIT to have one or more of its missions (ideally from the outset of planning) recognised as meeting the constellation standards and thereby satisfying the relevant user community needs.

Cramer, Bryant↗
NASA NTRS2012

Expedition Earth and Beyond: Using Crew Earth Observation Imagery from the International Space Station to Facilitate Student-Led Authentic Research

Student-led authentic research in the classroom helps motivate students in science, technology, engineering, and mathematics (STEM) related subjects. Classrooms benefit from activities that provide rigor, relevance, and a connection to the real world. Those real world connections are enhanced when they involve meaningful connections with NASA resources and scientists. Using the unique platform of the International Space Station (ISS) and Crew Earth Observation (CEO) imagery, the Expedition Earth and Beyond (EEAB) program provides an exciting way to enable classrooms in grades 5-12 to be active participants in NASA exploration, discovery, and the process of science. EEAB was created by the Astromaterials Research and Exploration Science (ARES) Education Program, at the NASA Johnson Space Center. This Earth and planetary science education program has created a framework enabling students to conduct authentic research about Earth and/or planetary comparisons using the captivating CEO images being taken by astronauts onboard the ISS. The CEO payload has been a science payload onboard the ISS since November 2000. ISS crews are trained in scientific observation of geological, oceanographic, environmental, and meteorological phenomena. Scientists on the ground select and periodically update a series of areas to be photographed as part of the CEO science payload.

Graff, P. V.↗
NASA NTRSDate not supplied

TPSAS-NF1676L-12770-DND

CEOS Action (Plenary 2010, Action 24-3): CEOS Chair to work with the SEO, outgoing and incoming CEO and GEO Secretariat to study possibilities for rationalisation of the multiplicity of portals provided by CEOS in support of GEO.

Brian Killough↗
NASA NTRSDate not supplied

National Aeronautics and Space Administration (NASA) Agency Report WGISS-51

The Committee on Earth Observation Satellites (CEOS) strives to enhance international coordination and data exchange and to optimize societal benefit. CEOS contributes to NASA’s core mission and is critical to NASA’s Earth Science program and to the future of Earth observations community as a whole because it advances mission planning, interagency coordination and technical implementation. Within NASA, the CEOS Working Group on Information System and Services (WGISS) is a forum for the Earth Sciences Data Systems (ESDS) Program to collaborate with other international and domestic agencies in the development of Earth observation data systems and services. NASA leads the development and demonstration of multiple prototypes supporting CEOS and Group on Earth Observations (GEO) requirements. NASA’s participation in WGISS influences NASA’s Earth Observing System Data and Information System’s (EOSDIS) ability to make high-quality data products available to the broad science community both nationally and internationally. Combined with NASA’s free and open data policy, EOSDIS’s involvement in WGISS is essential to widespread use of research satellite measurements. This presentation focuses on an overview and recent status of NASA’s EOSDIS.

Andrew Mitchell↗
NASA NTRSDate not supplied

NASA Agency Report WGISS 52

The Committee on Earth Observation Satellites (CEOS) strives to enhance international coordination and data exchange and to optimize societal benefit. CEOS contributes to NASA’s core mission and is critical to NASA’s Earth Science program and to the future of Earth observations community as a whole because it advances mission planning, interagency coordination and technical implementation. Within NASA, the CEOS Working Group on Information System and Services (WGISS) is a forum for the Earth Sciences Data Systems (ESDS) Program to collaborate with other international and domestic agencies in the development of Earth observation data systems and services. NASA leads the development and demonstration of multiple prototypes supporting CEOS and Group on Earth Observations (GEO) requirements. NASA’s participation in WGISS influences NASA’s Earth Observing System Data and Information System’s (EOSDIS) ability to make high-quality data products available to the broad science community both nationally and internationally. Combined with NASA’s free and open data policy, EOSDIS’s involvement in WGISS is essential to widespread use of research satellite measurements. This presentation focuses on an overview and recent status of NASA’s EOSDIS.

Andrew Mitchell↗
DOE OSTI2018

Confined Ultrathin Pd‐Ce Nanowires with Outstanding Moisture and SO 2 Tolerance in Methane Combustion

Abstract An efficient strategy (enhanced metal oxide interaction and core–shell confinement to inhibit the sintering of noble metal) is presented confined ultrathin Pd‐CeO x nanowire (2.4 nm) catalysts for methane combustion, which enable CH 4 total oxidation at a low temperature of 350 °C, much lower than that of a commercial Pd/Al 2 O 3 catalyst (425 °C). Importantly, unexpected stability was observed even under harsh conditions (800 °C, water vapor, and SO 2 ), owing to the confinement and shielding effect of the porous silica shell together with the promotion of CeO 2 . Pd‐CeO x solid solution nanowires (Pd‐Ce NW) as cores and porous silica as shells (Pd‐CeNW@SiO 2 ) were rationally prepared by a facile and direct self‐assembly strategy for the first time. This strategy is expected to inspire more active and stable catalysts for use under severe conditions (vehicle emissions control, reforming, and water–gas shift reaction).

Peng, Honggen↗
DOE OSTI2018

Confined Ultrathin Pd-Ce Nanowires with Outstanding Moisture and SO 2 Tolerance in Methane Combustion

Here, an efficient strategy (enhanced metal oxide interaction and core–shell confinement to inhibit the sintering of noble metal) is presented confined ultrathin Pd-CeO x nanowire (2.4 nm) catalysts for methane combustion, which enable CH 4 total oxidation at a low temperature of 350 °C, much lower than that of a commercial Pd/Al 2 O 3 catalyst (425 °C). Importantly, unexpected stability was observed even under harsh conditions (800 °C, water vapor, and SO 2 ), owing to the confinement and shielding effect of the porous silica shell together with the promotion of CeO 2 . Pd-CeO x solid solution nanowires (Pd-Ce NW) as cores and porous silica as shells (Pd-CeNW@SiO 2 ) were rationally prepared by a facile and direct self-assembly strategy for the first time. Finally, this strategy is expected to inspire more active and stable catalysts for use under severe conditions (vehicle emissions control, reforming, and water–gas shift reaction).

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

Understanding Support Effects of ZnO-Promoted Co Catalysts for Syngas Conversion to Alcohols Using Atomic Layer Deposition

Co 2 C, an emerging catalyst for the conversion of syngas to oxygenates, shows support-sensitive behavior that has not yet been fully explained. In this work, we characterize Co catalysts modified with ZnO atomic layer deposition on SiO 2 , carbon, CeO 2 , and Al 2 O 3 supports. We find that under syngas conditions, ZnO-promoted Co transforms into Co 2 C on SiO 2 , carbon, and CeO 2 , but not on Al 2 O 3 . Moreover, the support affects the extent of carburization: while the SiO 2 -supported catalyst carburizes completely, carbon- and CeO 2 -supported catalysts show incomplete conversion of Co to Co 2 C. These three catalysts also exhibit different oxygenate selectivities. In contrast, the modified Al 2 O 3 -supported catalyst retains the Fischer-Tropsch catalytic properties of metallic Co. By depositing increasing amounts of Al 2 O 3 by ALD on the SiO 2 support, decreasing Co 2 C formation and oxygenate selectivity occurs. In-situ XANES reveals that Al 2 O 3 prevents Co 2 C formation by enabling the ZnO to restructure into ZnAl 2 O 4 during reduction. Thus, in addition to modifying the active catalyst phase, the promoter can also strongly interact with the support, significantly impacting catalyst performance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗