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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 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

X-ray Computed Tomography of Irradiated and Unirradiated AGR-3/4 Compacts A preliminary examination

What? Performed X-ray CT (XCT) on irradiated AGR-3/4 compacts Apparatus design Imaging results Preliminary analysis Extruded kernels DTF Identification Areas of interest for further exploration Why? Can provide non-destructive 3D perspective to enhance/compliment current PIE Potentially better quantitative measurements of certain features Better means of understanding any spatial distribution(s)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2013

Preliminary Examination of Ethanol Fuel Effects on EPA’s R-factor for Vehicle Fuel Economy

The U.S. Department of Energy (DOE) supported a test program from 2007 through 2012 to evaluate the potential impacts of intermediate ethanol blends (also known as mid-level blends) on legacy vehicles and other engines. The purpose of the program was to assess the viability of using intermediate ethanol blends as a contributor to meeting national goals for the use of renewable fuels. Appendix A lists a bibliography of related studies. The catalyst durability program involved aging and emissions testing vehicles on a range of ethanol blends. The study was completed in 2011 and a final report issued shortly after. This report describes a preliminary analysis of the fuel economy data from the catalyst durability study, to determine the proper value for the R factor which is called out in the Code of Federal Regulations (CFR) for computing vehicle fuel economy on the certification cycle. The fuel economy equation that is specified in CFR for gasoline-fuelled vehicles is based on a carbon mass balance (CMB) approach to determine the amount of fuel consumed during the test by measuring the carbon-bearing emissions that are produced; however, it also incorporates a scaling factor (R factor) based on the net heating value of the fuel and the sensitivity of fuel economy to changes in the heating value. The impact of the R factor is a fixed ratio in the resultant fuel economy that is dependent upon fuel properties other than those required for a typical CMB calculation. This equation was put in place in 1988 to correct for differences between certification fuels to address corporate average fuel economy (CAFE) credit issues associated with fuel property variations. The algorithm adjusts the calculated fuel economy to compute what would have been measured had the 1975 certification fuel been used for the test. The R factor was defined as the sensitivity of the fuel economy result to changes in fuel energy content. When R equals 1.0, the fuel economy change exactly tracks the energy density difference between the fuels. If R is less than 1.0, the fuel economy change is smaller than the change in energy density. The R factor was defined to be 0.6 based on tests using 1980s vehicles. Since that time, the Auto/Oil test program has established that the R factor for 1990s vehicles is higher (about 0.93). More recently EPA analyzed the EPAct/V2/E-89 dataset to compute the R factor, resulting in an average of 0.82 to 0.86. It is important to note that the EPAct/V2/E89 test program used the LA92 test cycle, a cycle known to contain more aggressive accelerations than the FTP. To date, EPA has only required emissions and fuel economy testing of gasoline vehicles with a certification fuel that does not contain ethanol. However in 2013 EPA issued a Proposed Rule seeking comment on the establishment of an emissions certification fuel containing ethanol, such as E10 or E15. Calculating modern vehicle fuel economy with the existing CFR equation with an R factor of 0.6 when ethanol blends are used produces significant errors. For the catalyst durability program, a straightforward CMB approach was used to compute fuel economy, thereby allowing a straightforward evaluation of the impact of ethanol content on fuel economy. However, if an ethanol-containing fuel is to become the new certification fuel for light-duty vehicles, consistent application of the CFR equation needs to be considered for the benefit of manufacturers’ CAFE compliance. Analysis of city cycle Federal Test Procedure (FTP) fuel economy test results and fuel analyses from the catalyst durability study indicates that the average R-factor for modern vehicles is very close to unity at about 0.94±0.04. This result is very similar to the results of the 1993 Auto/Oil test program. Future work should examine other drive cycles, and advanced vehicle technologies which may reveal sensitivities to properties other than heating value.

intermediate ethanol blends↗
DOE OSTI2015

Evaluation of tritium release properties of advanced tritium breeders

Demonstration power plant (DEMO) fusion reactors require advanced tritium breeders with high thermal stability. Lithium titanate (Li{sub 2}TiO{sub 3}) advanced tritium breeders with excess Li (Li{sub 2+x}TiO{sub 3+y}) are stable in a reducing atmosphere at high temperatures. Although the tritium release properties of tritium breeders are documented in databases for DEMO blanket design, no in situ examination under fusion neutron (DT neutron) irradiation has been performed. In this study, a preliminary examination of the tritium release properties of advanced tritium breeders was performed, and DT neutron irradiation experiments were performed at the fusion neutronics source (FNS) facility in JAEA. Considering the tritium release characteristics, the optimum grain size after sintering is <5 μm. From the results of the optimization of granulation conditions, prototype Li{sub 2+x}TiO{sub 3+y} pebbles with optimum grain size (<5 μm) were successfully fabricated. The Li{sub 2+x}TiO{sub 3+y} pebbles exhibited good tritium release properties similar to the Li{sub 2}TiO{sub 3} pebbles. In particular, the released amount of HT gas for easier tritium handling was higher than that of HTO water. (authors)

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2020

Growth, total lipid, and omega-3 fatty acid production by Nannochloropsis spp. cultivated with raw plant substrate

Improving productivity and lipid concentration in microalgae is important for the economic success of both biofuel and microalgae coproducts production. Nannochloropsis spp. are marine microalgae currently being grown at large-scale for the production of biofuel and lipid coproducts. In this work, we demonstrate improvements of growth and omega-3 production in Nannochloropsis gaditana CCMP526 and Nannochloropsis oceanica CCAP849/10 with plant substrate addition, a potentially economical option for increasing microalgal productivity. Furthermore, we examine growth in the presence of corn stover, switchgrass, sugarcane bagasse, and yard waste. By examining the microbial ecology of N. gaditana cultures with and without plant substrate and with and without antibiotics, we discovered a potential bacterial interaction in these cultures, but its presence is not necessary for algal growth improvements in the presence of plant substrate. Analysis of plant substrate morphology by scanning electron microscopy (SEM) after cultivation in media with and without N. gaditana shows a degradation of specific plant structural features and a colonization of the plant phloem by N. gaditana. An examination of N. gaditana in a Congo red plate assay indicates potential cellulolytic activity, but a preliminary examination of the potential cellulase transcripts does not reveal differential expression of a candidate in the presence of plant. This evidence demonstrates potential raw plant utilization by a marine microalga for increased productivity and provides a potentially economical option for increasing coproduct concentration at industrial scale without genetic engineering.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

RCEMIP‐ACI: Aerosol‐Cloud Interactions in a Multimodel Ensemble of Radiative‐Convective Equilibrium Simulations

Aerosol‐cloud interactions are a persistent source of uncertainty in climate research. This study presents findings from a model intercomparison project examining the impact of aerosols on clouds and climate in convection‐permitting radiative‐convective equilibrium (RCE) simulations. Specifically, 11 different modeling teams conducted RCE simulations under varying aerosol concentrations, domain configurations, and sea surface temperatures (SSTs). We analyze the response of domain‐mean cloud and radiative properties to imposed aerosol concentrations across different SSTs. Additionally, we explore the potential impact of aerosols on convective aggregation and large‐scale circulation in large‐domain simulations. The results reveal that the cloud and radiative responses to aerosols vary substantially across models. However, a common trend across models, SSTs, and domain configurations is that increased aerosol loading tends to suppress warm rain formation, enhance cloud water content in the mid‐troposphere, and consequently increase mid‐tropospheric humidity and upper‐tropospheric temperature, thereby impacting static stability. The warming of the upper troposphere can be attributed to reduced lateral entrainment effects due to the higher environmental humidity in the mid‐troposphere. However, models do not agree on aerosol impacts on convective updraft velocity based on the preliminary examination of high‐percentiles of vertical velocity at a single mid‐troposheric layer (500 hPa). In large‐domain simulations, where convection tends to self‐organize, aerosol loading does not consistently influence self‐organization but tends to reduce the intensity of large‐scale circulation forming between convective clusters and dry regions. This reduction in circulation intensity can be explained by the increase in static stability due to the upper tropospheric warming.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Apollo Next Generation Sample Analysis (ANGSA): an Apollo Participating Scientist Program to Prepare the Lunar Sample Community for Artemis

As a first step in preparing for the return of samples from the Moon by the Artemis Program, NASA initiated the Apollo Next Generation Sample Analysis Program (ANGSA). ANGSA was designed to function as a low-cost sample return mission and involved the curation and analysis of samples previously returned by the Apollo 17 mission that remained unopened or stored under unique conditions for 50 years. These samples include the lower portion of a double drive tube previously sealed on the lunar surface, the upper portion of that drive tube that had remained unopened, and a variety of Apollo 17 samples that had remained stored at -27 °C for approximately 50 years. ANGSA constitutes the first preliminary examination phase of a lunar “sample return mission” in over 50 years. It also mimics that same phase of an Artemis surface exploration mission, its design included placing samples within the context of local and regional geology through new orbital observations collected since Apollo and additional new “boots-on-the-ground” observations, data synthesis, and interpretations provided by Apollo 17 astronaut Harrison Schmitt. ANGSA used new curation techniques to prepare, document, and allocate these new lunar samples, developed new tools to open and extract gases from their containers, and applied new analytical instrumentation previously unavailable during the Apollo Program to reveal new information about these samples. Most of the 90 scientists, engineers, and curators involved in this mission were not alive during the Apollo Program, and it had been 30 years since the last Apollo core sample was processed in the Apollo curation facility at NASA JSC. There are many firsts associated with ANGSA that have direct relevance to Artemis. ANGSA is the first to open a core sample previously sealed on the surface of the Moon, the first to extract and analyze lunar gases collected in situ, the first to examine a core that penetrated a lunar landslide deposit, and the first to process pristine Apollo samples in a glovebox at -20 °C. All the ANGSA activities have helped to prepare the Artemis generation for what is to come. The timing of this program, the composition of the team, and the preservation of unopened Apollo samples facilitated this generational handoff from Apollo to Artemis that sets up Artemis and the lunar sample science community for additional successes.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

An analysis of fluff formation in metallic fuel via data analyzes from EBR-II experiments and BISON fuel code modeling

During the operation of EBR-II, it was found that a highly porous structure (over 40% area fraction) formed at the top of several fuel columns. Previous work has shown that this structure, designated fluff in this paper, contains a significant fraction of fuel elements (e.g., U and Pu) which could potentially impact neutronics. This work aims in analyzing the formation mechanism of this microstructure so its impact can be incorporated into future metallic fuel modeling codes and algorithms. This paper details a preliminary examination into the formation mechanisms of fluff by performing qualitative and statistical analysis of EBR-II experimental data. Additionally, the operating conditions that have the greatest impact on fluff formation were determined based on this data set. Also, BISON fuel code simulations were used to help postulate potential fluff formation mechanisms. From this analysis it was found that the largest contributors to fluff formation were fuel burnup and composition, with fluff formation exhibiting a roughly linear positive correlation with increasing burnup and a negative correlation with increasing Pu content. It was also found that higher pin operating temperatures decreased fluff formation but only for U-10Zr fuels.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

Investigation of W-SiC compositionally graded films as a divertor material

W-SiC composite material is a promising plasma-facing material candidate alternative to pure W due to the low neutron activation, low impurity radiation, and low tritium diffusivity of SiC while leveraging the high erosion resistance of the W armor. Additionally, W and SiC have high thermomechanical compatibility given their similar thermal expansion rates. The present study addresses the synthesis and performance of compositionally graded W-SiC films fabricated by pulsed-DC magnetron sputtering. Compositional gradients were characterized using transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS), and crystallographic information was obtained using electron diffraction and X-ray diffraction (XRD). Samples were exposed to L-mode deuterium plasma discharges in the DIII-D tokamak using the Divertor Material Evaluation System (DiMES). Post-mortem characterizations were performed using scanning electron microscopy (SEM) and XRD. Electron diffraction and XRD showed that the compositionally graded W-SiC films were composed of polycrystalline W and amorphous SiC with amorphous W+SiC interlayers. No macroscopic delamination or microstructural changes were observed under mild exposure conditions. Here, this study serves as a preliminary examination of W-SiC compositionally graded composites as a potential candidate divertor material in future tokamak devices.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Assessing the Effect of Parametric Uncertainty on the FRAPCON-3.4 Thermal Conductivity Model

In the absence of a well-accepted, mathematical description of how units of material respond to one or more external actions, scientists must often rely upon empirically-derived models to make predictions. These models are often employed to model very complex phenomena, with an unfortunate side-effect that intuition, as to the values of particular model parameters, may not serve to guide their use. Given our increased reliance on modeling and simulation to make predictions in the absence of experimental data, it befits the scientific and engineering communities to explore and report upon uncertainty quantification techniques applied to previously adopted (or at least well-accepted) empirical models that derive from or pertain to substantial experimental data sets. This report represents a collection of three methodologies aimed at assessing the predictive capability of the empirical thermal conductivity model adopted by the nuclear fuel performance code, FRAPCON-3.4. Each of these methodologies considers the effect of uncertain parameters – a plausible reality in the context of empirically-derived models – on the ability of the model to predict uranium dioxide conductivity data from open literature sources. The results lead the authors to question the predictive capability of the FRAPCON model for predicting the thermal conductivities associated with irradiated fuel samples. The report concludes with a preliminary examination of Idaho National Laboratory’s (INL) nuclear fuel performance code, BISON, developed under INL’s Multiphysics Object Oriented Simulation Environment (MOOSE).

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2014

A Preliminary Review of U.S. Forest Service Business Practices To Authorize Special Uses, Including Energy Infrastructure Projects, on National Forest System Lands

The U.S. Forest Service (USFS) Special Uses-Lands Program is in jeopardy. Although this program, authorized in Title 36, Part 251, of the U.S. Code of Federal Regulations (36 CFR Part 251), ranks among the top four revenue-generating programs for use of National Forest System (NFS) lands, along with the Timber, Minerals, and Special Uses-Recreation Programs, the Special Uses-Lands Program is in a state of neglect. Repeated cuts in funding (a decrease of 26% from fiscal years 2010 to 2014) are adversely affecting staffing and training, which in turn is affecting timely permit processing and ultimately the public’s ability to use and benefit from NFS lands. In addition, highly experienced staff with valuable institutional knowledge of the program have begun to retire. The ability of the program to function under these dire circumstances can be attributed to the dedication of Special Uses staff to the program and their commitment to the public. The initial focus of this report was to identify opportunities for improving performance of permitting and review for large energy infrastructure-related projects. However, it became clear during this analysis that these projects are generally adequately staffed and managed. This is due in large part to the availability of cost-recovery dollars and the high-profile nature of these projects. However, it also became apparent that larger issues affecting the bulk of the work of the Special Uses-Lands Program need to be addressed immediately. This report is a preliminary examination of the state of the Special Uses-Lands Program and focuses on a few key items requiring immediate attention. Further investigation through case studies is recommended to dig deeper into the Special Uses-Lands Program business process to determine the most costeffective strategies for streamlining the overall process and the metrics by which performance can be evaluated, including for the permitting and tracking of energy infrastructure projects.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2019

Preliminary Hyde Memorial State Park Modular Pumped Hydro Energy Storage Sizing Study

Hyde Memorial State Park has lost grid supplied power and has been running on a diesel generator for some time now. The powerline that feeds the park is a state owned, 5 mile underground extension from the PNM service connection point. The line has decayed over the past 30 plus years and due to the location (much of it running under the road) the cost of repair and the logistics of closing the road are not good options. In June 2019 through a state contractor, the State of New Mexico Energy, Minerals and Natural Resources Department completed a renewable energy microgrid feasibility study to see if it was technically and economically feasible to operate the park without future grid power. The study looked at solar plus battery storage and a propane generator as a possible option. New Mexico State Parks Division has indicated their wish to move forward with the microgrid project which will now go out to one of the state’s energy services performance contractors. The contractor will have to finalize the feasibility study and develop a complete list of construction costs. Given, the lack of long-term O&M data on the battery, as part of the next phase of the project the State of New Mexico Energy, Minerals and Natural Resources Department asked Los Alamos National Laboratory to preliminary examine the potential for pumped hydro as an alternative to batteries.

13 HYDRO ENERGY↗
DOE OSTI2012

New Homogeneous Standards by Atomic Layer Deposition for Synchrotron X-ray Fluorescence and Absorption Spectroscopies.

Quantification of synchrotron XRF analyses is typically done through comparisons with measurements on the NIST SRM 1832/1833 thin film standards. Unfortunately, these standards are inhomogeneous on small scales at the tens of percent level. We are synthesizing new homogeneous multilayer standards using the Atomic Layer Deposition technique and characterizing them using multiple analytical methods, including ellipsometry, Rutherford Back Scattering at Evans Analytical, Synchrotron X-ray Fluorescence (SXRF) at Advanced Photon Source (APS) Beamline 13-ID, Synchrotron X-ray Absorption Spectroscopy (XAS) at Advanced Light Source (ALS) Beamlines 11.0.2 and 5.3.2.1 and by electron microscopy techniques. Our motivation for developing much-needed cross-calibration of synchrotron techniques is borne from coordinated analyses of particles captured in the aerogel of the NASA Stardust Interstellar Dust Collector (SIDC). The Stardust Interstellar Dust Preliminary Examination (ISPE) team have characterized three sub-nanogram, {approx}1{micro}m-sized fragments considered as candidates to be the first contemporary interstellar dust ever collected, based on their chemistries and trajectories. The candidates were analyzed in small wedges of aerogel in which they were extracted from the larger collector, using high sensitivity, high spatial resolution >3 keV synchrotron x-ray fluorescence spectroscopy (SXRF) and <2 keV synchrotron x-ray transmission microscopy (STXM) during Stardust ISPE. The ISPE synchrotron techniques have complementary capabilities. Hard X-ray SXRF is sensitive to sub-fg mass of elements Z {ge} 20 (calcium) and has a spatial resolution as low as 90nm. X-ray Diffraction data were collected simultaneously with SXRF data. Soft X-ray STXM at ALS beamline 11.0.2 can detect fg-mass of most elements, including cosmochemically important oxygen, magnesium, aluminum and silicon, which are invisible to SXRF in this application. ALS beamline 11.0.2 has spatial resolution better than 25 nm. Limiting factors for Stardust STXM analyses were self-imposed limits of photon dose due to radiation damage concerns, and significant attenuation of <1500 eV X-rays by {approx}80{micro}m thick, {approx}25 mg/cm{sup 3} density silica aerogel capture medium. In practice, the ISPE team characterized the major, light elements using STXM (O, Mg, Al, Si) and the heavier minor and trace elements using SXRF. The two data sets overlapped only with minor Fe and Ni ({approx}1% mass abundance), providing few quantitative cross-checks. New improved standards for cross calibration are essential for consortium-based analyses of Stardust interstellar and cometary particles, IDPs. Indeed, they have far reaching application across the whole synchrotron-based analytical community. We have synthesized three ALD multilayers simultaneously on silicon nitride membranes and silicon and characterized them using RBS (on Si), XRF (on Si{sub 3}N{sub 4}) and STXM/XAS (holey Si{sub 3}N{sub 4}). The systems we have started to work with are Al-Zn-Fe and Y-Mg-Er. We have found these ALD multi-layers to be uniform at {micro}m- to nm scales, and have found excellent consistency between four analytical techniques so far. The ALD films can also be used as a standard for e-beam instruments, eg., TEM EELS or EDX. After some early issues with the consistency of coatings to the back-side of the membrane windows, we are confident to be able to show multi-analytical agreement to within 10%. As the precision improves, we can use the new standards to verify or improve the tabulated cross-sections.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

Towards a Scalable Group Vehicle-based Security System

In August 2014, the National Highway Traffic Safety Administration (NHTSA) proposed new rulemaking to require V2V communication in light vehicles. To establish trust in the basic safety messages (BSMs) that are exchanged by vehicles to improve driver safety, a vehicle public key infrastructure (VPKI) is required. We outline a system where a group or groups of vehicles manage and generate their own BSM signing keys and authenticating certificates -- a Vehicle-Based Security System (VBSS). Based on our preliminary examination, we assert the mechanisms exist to implement a VBSS that supports V2V communications; however, maintaining uniform trust throughout the system while protecting individual privacy does require reliance on nascent group signature technology which may require a significant amount of communication overhead for trust maintenance. To better evaluate the VBSS approach, we compare it to the proposed Security Credential Management System (SCMS) in four major areas including bootstrapping, pseudonym provisioning, BSM signing and authentication, and revocation. System scale, driver privacy, and the distribution and dynamics of participants make designing an effective VPKI an interesting and challenging problem; no clear-cut strategy exists to satisfy the security and privacy expectations in a highly efficient way. More work is needed in VPKI research, so the life-saving promise of V2V technology can be achieved.

Carter, Jason M↗
DOE OSTI2018

Wind Plant Performance Prediction (WP3) Project

The methods for analysis of operational wind plant data are highly variable across the wind industry, leading to high uncertainties in the validation and bias-correction of preconstruction energy estimation methods. Lack of credibility in the preconstruction energy estimates leads to significant impacts on project financing and therefore the final levelized cost of energy for the plant. In this work, the variation in the evaluation of a wind plant's operational energy production as a result of variations in the processing methods applied to the operational data is examined. Preliminary results indicate that selection of the filters applied to the data and the filter parameters can have significant impacts in the final computed assessment metrics.

17 WIND ENERGY↗