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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Understanding EV Charging Pain Points Through Deep Learning Analysis

Current and potential electric vehicle (EV) owners express concerns about the charging infrastructure, mentioning non-functional chargers, prolonged charging times, inconvenient charger locations, long wait times, and high costs as major barriers. Addressing these issues often requires analyzing actual vehicle charging data, which is typically proprietary and inconsistent due to diverse standards and protocols. To understand and improve the EV charging experience, customer reviews are typically used to identify common customer pain points (CPPs). However, there is not a comprehensive method to map customer reviews to a standardized set of CPPs. In collaboration with the National Charging Experience (ChargeX) Consortium, this study bridges these gaps by proposing a Systematic Categorization and Analysis of Large-scale EV-charging Reviews (SCALER) framework. SCALER is an integrated, deep learning framework that segments, actively labels, analyzes, and classifies EV charging customer reviews into six CPP categories. To test its effectiveness, we used SCALER to analyze over 72,000 reviews from customers charging various EV models on different networks across the United States. SCALER achieves a classification accuracy of 92.5%, with an F1 score exceeding 85.7%. By demonstrating real-world applications of SCALER, we enhance the industry’s ability to understand and address CPPs to improve the EV charging experience.

29 - ENERGY PLANNING, POLICY AND ECONOMY↗
NASA NTRS1984

Composites for large transports - Facing the challenge

NASA has undertaken development and test programs in collaboration with the large transport aircraft construction industry, in order to remove existing barriers to the use of composite material primary structures and to assess their advantages in terms of both acquisition cost and mission performance. These programs are expected to reach design technology readiness for wing and fuselage structures by 1988, paving the way for the validation of design and manufacturing methods in the early 1990s. While composites promise a reduction in fuselage manufacturing costs, it is judged that the relative cost of a metallic wing will be more difficult to surpass. Nevertheless, a 40 percent wing weight saving may more than compensate for increased wing structure cost.

Bohon, H. L.↗
NASA NTRS2001

Nano-Transistor Modeling: Two Dimensional Green's Function Method

Two quantum mechanical effects that impact the operation of nanoscale transistors are inversion layer energy quantization and ballistic transport. While the qualitative effects of these features are reasonably understood, a comprehensive study of device physics in two dimensions is lacking. Our work addresses this shortcoming and provides: (a) a framework to quantitatively explore device physics issues such as the source-drain and gate leakage currents, DIBL (Drain Induced Barrier Lowering), and threshold voltage shift due to quantization, and b) a means of benchmarking quantum corrections to semiclassical models (such as density-gradient and quantum-corrected MEDICI).

Svizhenko, Alexei↗
NASA NTRS2002

Defining the Polar Vortex Edge from a N20: Potential Temperature Correlation

A prerequisite to studying phenomena in the winter stratospheric polar vortex is the separation of measurements inside and outside the dynamical barrier of the vortex edge. We describe a technique to accurately determine the inner edge of the vortex boundary region from measurements of potential temperature and a trace gas, such as N2O, and apply it to in situ aircraft and balloon measurements from the SOLVE/THESEO 2000 Arctic campaign. The method may be used to refine the Nash algorithm, which, due to the inherently coarser resolution of potential vorticity on which it is dependent, may misidentify the inner edge by more than 400 km and omit the identification of small, extravortex filaments within the vortex.

Greenblatt, Jeffery B.↗
NASA NTRS2010

Submonolayer Quantum Dot Infrared Photodetector

A method has been developed for inserting submonolayer (SML) quantum dots (QDs) or SML QD stacks, instead of conventional Stranski-Krastanov (S-K) QDs, into the active region of intersubband photodetectors. A typical configuration would be InAs SML QDs embedded in thin layers of GaAs, surrounded by AlGaAs barriers. Here, the GaAs and the AlGaAs have nearly the same lattice constant, while InAs has a larger lattice constant. In QD infrared photodetector, the important quantization directions are in the plane perpendicular to the normal incidence radiation. In-plane quantization is what enables the absorption of normal incidence radiation. The height of the S-K QD controls the positions of the quantized energy levels, but is not critically important to the desired normal incidence absorption properties. The SML QD or SML QD stack configurations give more control of the structure grown, retains normal incidence absorption properties, and decreases the strain build-up to allow thicker active layers for higher quantum efficiency.

Ting, David Z.↗
NASA NTRS2009

Determination of Scattering and Absorption Coefficients for Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings at Elevated Temperatures

The temperature dependence of the scattering and absorption coefficients for a set of freestanding plasma-sprayed 8 wt% yttria-stabilized zirconia (8YSZ) thermal barrier coatings (TBCs) was determined at temperatures up to 1360 C in a wavelength range from 1.2 micrometers up to the 8YSZ absorption edge. The scattering and absorption coefficients were determined by fitting the directional-hemispherical reflectance and transmittance values calculated by a four-flux Kubelka Munk method to the experimentally measured hemispherical-directional reflectance and transmittance values obtained for five 8YSZ thicknesses. The scattering coefficient exhibited a continuous decrease with increasing wavelength and showed no significant temperature dependence. The scattering is primarily attributed to the relatively temperature-insensitive refractive index mismatch between the 8YSZ and its internal voids. The absorption coefficient was very low (less than 1 per centimeter) at wavelengths between 2 micrometers and the absorption edge and showed a definite temperature dependence that consisted of a shift of the absorption edge to shorter wavelengths and an increase in the weak absorption below the absorption edge with increasing temperature. The shift in the absorption edge with temperature is attributed to strongly temperature-dependent multiphonon absorption. While TBC hemispherical transmittance beyond the absorption edge can be predicted by a simple exponential decrease with thickness, below the absorption edge, typical TBC thicknesses are well below the thickness range where a simple exponential decrease in hemispherical transmittance with TBC thickness is expected. [Correction added after online publication August 11, 2009: "edge to a shorter wavelengths" has been updated as edge to shorter wavelengths."]

Eldridge, Jeffrey I.↗
NASA NTRS2015

Method and Apparatus for a Miniature Bioreactor System for Long-Term Cell Culture

A bioreactor and method that permits continuous and simultaneous short, moderate, or long term cell culturing of one or more cell types or tissue in a laminar flow configuration is disclosed, where the bioreactor supports at least two laminar flow zones, which are isolated by laminar flow without the need for physical barriers between the zones. The bioreactors of this invention are ideally suited for studying short, moderate and long term studies of cell cultures and the response of cell cultures to one or more stressors such as pharmaceuticals, hypoxia, pathogens, or any other stressor. The bioreactors of this invention are also ideally suited for short, moderate or long term cell culturing with periodic cell harvesting and/or medium processing for secreted cellular components.

Kleis, Stanley J.↗
NASA NTRS2024

Bringing the Heat: Thermal Protection Systems for Low Earth Orbit Transportation and Lunar Exploration

Thermal protection systems (TPS) protect spacecraft from the heating associated with hypersonic flight through a planet’s atmosphere. The materials are subjected to extreme heating and the overall system must be engineered to reliably protect the spacecraft structure during atmospheric entry. The talk will introduce TPS and describe three NASA-led efforts to develop TPS materials and manufacturing processes. The first effort studied thermally stable ceramic aerogels for use in thermal barriers and high temperature seals. A design framework for such materials is proposed, linking the thermal stability performance data with existing material property measurements. The second project, Additive Manufacturing of Thermal Protection Systems (AMTPS), developed an automated, additive approach for ablative heat shield manufacturing. Novel material systems and manufacturing methods were developed to reduce the time required to manufacture ablative TPS heat shields. The third effort tackles a critical challenge of material obsolescence for silica fiber based reusable TPS. The properties and performance of heritage silica fiber are quantified and compared to modern alternatives to support qualification for flight. The talk will also describe other work in TPS conducted by the Thermal Design Branch at NASA JSC and opportunities for students and faculty to get involved with NASA.

Nathaniel Olson↗
DOE OSTI2024

Thermally Insulating Transparent Barrier (THINNER) coatings on single pane windows

Conventional silica aerogel monoliths can provide remarkable thermal insulation but the presence of large pores (> 30 nm) tends to scatter visible light and render the material opaque or translucent instead of transparent. In addition, they are prone to cracking during synthesis and handling which makes them difficult to integrate in products and in particular in window solutions. This project developed two new solgel synthesis methods using silica precursors or preformed silica nanoparticles and ambient drying to produce mesoporous organo-silica monoliths. The monoliths were (i) thermally insulating, (ii) optically transparent, (iii) flexible, and (iv) hydrophobic. They feature porosity ranging from 50% to 90% with narrow pore size distribution with pore less than 20 nm resulting in excellent optical clarity (haze < 2%) and very low thermal conductivity (< 30 mW/mK). Interestingly, not only porosity but also pore size and mass fractal dimension were found to affect the thermal conductivity of the mesoporous silica. The superior transparency of the monoliths was shown to be attributed to dependent scattering among silica nanoparticles. Flexibility was achieved through trimethylchlorosilane surface modification. Furthermore, process scale-up and integration of the ambigel monoliths into window solutions using optically clear adhesives were also demonstrated in 6”x6” double-pane windows. The aerogel and the window solution were shown to be durable to accelerated aging under UV, moisture, and/or temperature gradient and thermal cycling. Overall, the window solution achieved the technical performance and the cost target of $10/sqft set for the SHIELD program. However, scaling to industry relevant scale (> 10’x10’) remains a challenge due to requirements on the drying process and fume hood size and to the propensity of large aerogel slab to crack during drying.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

COnfirmation using Gamma-ray Non-Imaging Zero-knowledge ANti-mask Time-encoding (COGNIZANT) Final Summary Report

In potential future arms reduction treaties in which the numbers of nuclear warheads may approach small numbers, using delivery systems as a proxy for the warheads themselves may be insufficient. Therefore, a technical means of verifying the presence of a nuclear warhead may become necessary. Verifying that a declared item actually is a warhead is technically challenging within a verification regime: providing assurance to the monitoring party that a presented item is a warhead while protecting sensitive information about that warhead may be required. It is generally believed that strong assurance will require the confirmation of key attributes that may reveal closely-guarded critical design information. This provides high confidence to the monitoring party, but presents a risk of information loss to the host. A verification system must overcome this hurdle. Over the last several decades, systems have been developed that balance host and monitoring partner needs by using sensitive information to confirm treaty accountable items (TAI) as warheads while sequestering that information behind an information barrier (1). These are designed to meet the needs of the host but places the onus on the monitor to authenticate the hardware, firmware, and software. Authentication requires that the monitor confirm that all components of the system have not been modified and work as intended. In 2014, Glaser et al. proposed applying the concept of “zero knowledge protocols” (ZKP) from the field of cryptography to the problem of warhead verification (2). In mathematical cryptography, ZKP is accomplished by challenging one party to solve a problem that is only possible if that party possesses the information being authenticated. After repeated challenges, the party provides confidence that it possesses this information without revealing any details about the information itself. Systems have been in development based on this idea at both Princeton and MIT (2) (3) (4). The final measurement results produced by these systems can be viewed by both the host and the monitoring party without the worry of revealing sensitive information. However, in both of these physical implementations, there remains an information barrier within the system. The need for a digital information barrier to protect a measurement result is eliminated, but it has been replaced with the need to sequester physical components of the system, potentially obfuscating the measurement process itself. Both implementations physically insert information into the system that requires protection to prevent undesired disclosure of sensitive information: in the Princeton method, one must physically load the complement of the expected image of a true warhead into the system, and in the MIT technique, one loads a collection of spectator foils whose thicknesses physically encrypt a measured spectrum. This complicates authentication of the hardware and measurement process. The CONFIDANTE/COGNIZANT concept developed in this project do not load sensitive information into the system at any time, and could therefore open the possibility of allowing the inspector to not only view the final data but also the measurement as it is being performed and all associated equipment.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
NASA NTRS1999

Chemical Vapor Deposition of Turbine Thermal Barrier Coatings

Ceramic thermal barrier coatings extend the operating temperature range of actively cooled gas turbine components, therefore increasing thermal efficiency. Performance and lifetime of existing ceram ic coatings are limited by spallation during heating and cooling cycles. Spallation of the ceramic is a function of its microstructure, which is determined by the deposition method. This research is investigating metalorganic chemical vapor deposition (MOCVD) of yttria stabilized zirconia to improve performance and reduce costs relative to electron beam physical vapor deposition. Coatings are deposited in an induction-heated, low-pressure reactor at 10 microns per hour. The coating's composition, structure, and response to the turbine environment will be characterized.

Haven, Victor E.↗
NASA NTRS2003

Thermal Response of Cooled Silicon Nitride Plate Due to Thermal Conductivity Effects Analyzed

Lightweight, strong, tough high-temperature materials are required to complement efficiency improvements for next-generation gas turbine engines that can operate with minimum cooling. Because of their low density, high-temperature strength, and high thermal conductivity, ceramics are being investigated as materials to replace the nickelbase superalloys that are currently used for engine hot-section components. Ceramic structures can withstand higher operating temperatures and a harsh combustion environment. In addition, their low densities relative to metals help reduce component mass (ref. 1). To complement the effectiveness of the ceramics and their applicability for turbine engine applications, a parametric study using the finite element method is being carried out. The NASA Glenn Research Center remains very active in conducting and supporting a variety of research activities related to ceramic matrix composites through both experimental and analytical efforts (ref. 1). The objectives of this work are to develop manufacturing technology, develop a thermal and environmental barrier coating (TBC/EBC), develop an analytical modeling capability to predict thermomechanical stresses, and perform a minimal burner rig test on silicon nitride (Si3N4) and SiC/SiC turbine nozzle vanes under simulated engine conditions. Moreover, we intend to generate a detailed database of the material s property characteristics and their effects on structural response. We expect to offer a wide range of data since the modeling will account for other variables, such as cooling channel geometry and spacing. Comprehensive analyses have begun on a plate specimen with Si3N4 cooling holes.

Baaklini, George Y.↗
NASA NTRS2011

Conclusion

This compilation of papers in this book represents approximately half of the works discussed at the MS&T 2010 symposium entitled Tools, Models, Databases, and Simulation Tools Developed and Needed to Realize the Vision of Integrated Computational Materials Engineering at Materials Science & Technology wherein five sessions comprised of 33 presentations was organized. The goal of the symposium was two fold To provide a forum in which current state-of-the-art methods for ICME (e.g., information informatics, experimentation, and modeling) could be openly discussed and critiqued by not only materials scientist but also structural engineers/researchers, component designers, industrial leaders and government program managers. To leave the symposium and in particular the panel discussion with a clear idea of the gaps and barriers (both technical, cultural and economical) that must be addressed in order for ICME to fully succeed. The organizers felt that these goals were met, as particularly evident by the standing room only attendance during a lively panel discussion session at the end of the Symposium. However it is the firm belief of the editors of this book that this symposium was merely a start in the right direction, and that subsequent conferences/symposium (e.g., First World Congress on Integrated Computational Materials Engineering to be held July 10-14, 2011 at Seven Springs Mountain Resort in Pennsylvania) must work hard to ensure that a truly diverse, multidisciplinary, community of researchers and practitioners are present and have ample opportunity for interaction. This will ensure that a proper balance between push and pull disciplines and technologies is maintained so that this emerging focus area, Integrated Computational Materials Engineering (ICME), has the greatest potential for success and impact on "system-level" payoffs. Similarly, a pro-active approach is required to reform historical modes of operation in industry, government and the academic sectors so as to facilitate multidisciplinary collaboration and to clearly articulate the vision and scope of ICME.

Arnold, Steven M.↗
NASA NTRS2017

Embracing Open Source for NASA's Earth Science Data Systems

The overarching purpose of NASAs Earth Science program is to develop a scientific understanding of Earth as a system. Scientific knowledge is most robust and actionable when resulting from transparent, traceable, and reproducible methods. Reproducibility includes open access to the data as well as the software used to arrive at results. Additionally, software that is custom-developed for NASA should be open to the greatest degree possible, to enable re-use across Federal agencies, reduce overall costs to the government, remove barriers to innovation, and promote consistency through the use of uniform standards. Finally, Open Source Software (OSS) practices facilitate collaboration between agencies and the private sector. To best meet these ends, NASAs Earth Science Division promotes the full and open sharing of not only all data, metadata, products, information, documentation, models, images, and research results but also the source code used to generate, manipulate and analyze them. This talk focuses on the challenges to open sourcing NASA developed software within ESD and the growing pains associated with establishing policies running the gamut of tracking issues, properly documenting build processes, engaging the open source community, maintaining internal compliance, and accepting contributions from external sources. This talk also covers the adoption of existing open source technologies and standards to enhance our custom solutions and our contributions back to the community. Finally, we will be introducing the most recent OSS contributions from NASA Earth Science program and promoting these projects for wider community review and adoption.

Earth Science↗
DOE OSTI2022

A comprehensive experimental and kinetic modeling study of di-isobutylene isomers: Part 2

A wide variety of high temperature experimental data obtained in this study complement the data on the oxidation of the two di-isobutylene isomers presented in Part I and offers a basis for an extensive validation of the kinetic model developed in this study. Due to the increasing importance of unimolecular decomposition reactions in high-temperature combustion, we have investigated the di-isobutylene isomers in high dilution utilizing a pyrolysis microflow reactor and detected radical intermediates and stable products using vacuum ultraviolet (VUV) synchrotron radiation and photoelectron photoion coincidence (PEPICO) spectroscopy. Additional speciation data at oxidative conditions were also recorded utilizing a plug flow reactor at atmospheric pressure in the temperature range 725-1150 K at equivalence ratios of 1.0 and 3.0 and at residence times of 0.35 s and 0.22 s, respectively. Combustion products were analyzed using gas chromatography (GC) and mass spectrometry (MS). Ignition delay time measurements for di-isobutylene were performed at pressures of 15 and 30 bar at equivalence ratios of 0.5, 1.0, and 2.0 diluted in 'air' in the temperature range 900-1400 K using a high-pressure shock-tube facility. New measurements of the laminar burning velocities of di-isobutylene/air flames are also presented. The experiments were performed using the heat flux method at atmospheric pressure and initial temperatures of 298-358 K. Moreover, data consistency was assessed with the help of analysis of the temperature and pressure dependencies of laminar burning velocity measurements, which was interpreted using an empirical power-law expression. Electronic structure calculations were performed to compute the energy barriers to the formation of many of the product species formed. The predictions of the present mechanism were found to be in adequate agreement with the wide variety of experimental measurements performed.

09 BIOMASS FUELS↗
DOE OSTI2025

Diffusion behavior of lanthanide fission products in bcc Fe cladding: A first-principles study

Fuel-cladding chemical interaction poses significant challenges in nuclear reactors, where fission products generated from nuclear fuel interact with Fe-based cladding materials, potentially compromising their structural integrity. This study investigates the diffusion behavior of lanthanide fission products, Lanthanum (La), Cerium (Ce), Praseodymium (Pr), and Neodymium (Nd), within body-centered cubic (bcc) Fe cladding using the density functional theory, nudged elastic band method, and self-consistent mean field theory. Our results reveal significant vacancy binding energies, particularly with the 1st and 2nd nearest neighbors, which diminish beyond the 5th nearest neighbor, with La exhibiting the strongest binding affinity, followed by Nd, Ce, and Pr. The nudged elastic band calculations indicate significant high barriers for the dissociation of 1st nearest neighbor vacancy-solute pairs for all fission products. The tracer diffusion coefficients of these fission products were derived in an Arrhenius form, with a magnetic correction that accounts for the high-temperature paramagnetic state. The significant trapping effect of vacancies caused by a very dilute concentration of fission products reduces vacancy mobility, potentially leading to modifications in point defect supersaturation, void nucleation, and swelling under irradiation. These represent critical challenges for irradiated cladding materials. The tracer diffusion coefficients indicate that Nd diffuses the fastest, followed by La, Ce, and Pr. Furthermore, this study provides essential insights for understanding fission product transport in cladding materials and informs future design strategies to mitigate fuel-cladding chemical interaction, ultimately enhancing nuclear reactor safety and performance.

Diffusion↗
DOE OSTI2020

Robust galactomannan/graphene oxide film with ultra-flexible, gas barrier and self-clean properties

Here, this study examines a facile technology to manufacture food packaging alternatives with superior mechanical, ultra-flexible, gas barrier and self-cleaning properties, based on green and benign starting materials. A novel galactomannan (GM) was isolated from the Sesbania cannabina seeds, which was used as a matrix for the fabrication of GM-based films. Inspired by the brick-and-mortar structure of natural nacre, a facile method was adopted to fabricate an artificial nacre based on the self-assembly of GM and borate crosslinked graphene oxide (GO). These GM/GO composites are ultra-flexible, which can be folded into various shapes. The tensile strength reached 135.54 MPa which is 2.40 times that of the pure GM film. In addition, after coating with the poly(dimethylsiloxane) (PDMS), these films became hydrophobic (WCA around 120°) with self-cleaning properties. Our study further revealed that the oxygen and water vapor permeabilities were improved with the introduction of GO and PDMS coating.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Improved chemical synthesis, identification and evaluation of prospective centrally active oxime antidotes for the treatment of nerve agent exposure

In this study, an improved method for the synthesis of hydroxyiminoacetamide-based oximes, compounds rhat hold great promise as centrally-active nerve agent antidotes, is described. The method involves the coupling of hydroxyiminoacetic acid to various amines in the presence of HOBT or HATU and diisopropylcarbodiimide. The optimized protocol was found to work effectively for the coupling with amines to the activated form of the hydroxyiminoacetic acid with yields ranging between 84 and 90% for primary amines, 65–75% for α-substituted and cyclic amines, while producing decent 41–48% yields for the sterically hindered α,α-substituted amines, that can not be obtained using the previously established method.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗