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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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NASA NTRS1984

Report of the Panel on Materials

Materials and manufacturing technology are critical to advanced aircraft and permeate all disciplines. Current aircraft systems employ a variety of materials, each selected to provide the best vehicle design in terms of performance, safety, reliability, manufacturability, and life cycle cost. However, a mistake in materials selection could bankrupt an airframe or engine manufacturer. Thus, the introduction of new materials is a slow process. Generally, new materials are used initially in noncritical components until their performance in service can be confirmed. Then, as confidence grows, they are used in more and more critical applications. Finally, if appropriate, new materials are used in critical, static elements and then in dynamic components. Thus, because the nominal time for development of a conventional monolithic material ranges from 5 to 10 years there is a 10- to 15- year lag between laboratory effort and introduction into service. Therefore, to assure the availability of materials suitable for production aircraft and engines in the year 2000, the concepts already must have been identified and must be progressing along evolutionary paths toward application. Trends, actual and projected, in the use of materials for commercial engines are shown in Figure 4-1. Related military applications are projected to follow similar paths. The new actor will be composites. The panel examined a wide range of materials important to all aspects of aircraft development, airframe structures, propulsion systems and for other important aircraft subsystems. These are addressed in the body of the report in terms of the current state of the art, opportunities for improvement, and barriers to achievement of projected benefits. This is followed by projections of the progress of technology that could be realized by the year 2000 with the application of appropriate resources.

Diefendorf, Russell J.↗
NASA NTRS2012

POSTMAN: Point of Sail Tacking for Maritime Autonomous Navigation

Waves apply significant forces to small boats, in particular when such vessels are moving at a high speed in severe sea conditions. In addition, small high-speed boats run the risk of diving with the bow into the next wave crest during operations in the wavelengths and wave speeds that are typical for shallow water. In order to mitigate the issues of autonomous navigation in rough water, a hybrid controller called POSTMAN combines the concept of POS (point of sail) tack planning from the sailing domain with a standard PID (proportional-integral-derivative) controller that implements reliable target reaching for the motorized small boat control task. This is an embedded, adaptive software controller that uses look-ahead sensing in a closed loop method to perform path planning for safer navigation in rough waters. State-of-the-art controllers for small boats are based on complex models of the vessel's kinematics and dynamics. They enable the vessel to follow preplanned paths accurately and can theoretically control all of the small boat s six degrees of freedom. However, the problems of bow diving and other undesirable incidents are not addressed, and it is questionable if a six-DOF controller with basically a single actuator is possible at all. POSTMAN builds an adaptive capability into the controller based on sensed wave characteristics. This software will bring a muchneeded capability to unmanned small boats moving at high speeds. Previously, this class of boat was limited to wave heights of less than one meter in the sea states in which it could operate. POSTMAN is a major advance in autonomous safety for small maritime craft.

Huntsberger, Terrance L.↗
NASA NTRSDate not supplied

Hot Structure Concepts and Materials for Space Exploration Project

Hot structures are multifunctional material systems that integrate the functions of thermal protection systems (TPS) and primary structure to increase mass efficiency in aerospace vehicles. The goal of this project was to improve our capabilities for developing lightweight, reusable, and reliable hot structures concepts to enable advanced space exploration missions. Specifically, current hot structure carbon/carbon (C/C) composite material systems have low interlaminar strength, which can lead to material failures at low load levels, and large material property variability in as-fabricated parts. Two parallel paths were followed to address these shortcomings. First, analysis models were developed to identify the conditions under which excessive interlaminar stresses occur and to evaluate the potential of stitching the C/C laminae to improve the interlaminar thermal-structural response. This effort included the development of high-fidelity, fracture-based thermal-structural finite element analysis models to evaluate critical features needed to produce efficient hot structure concepts. The second path focused on developing atomistic and mesoscale simulation tools to model the fabrication process in an effort to reduce the time and cost of production while improving the quality of the resulting parts. Aspects of the process currently being investigated include the infusion of the matrix precursor into the fiber preform, the cure of the precursor molecules into their polymeric form, and the carbonization and graphitization of the polymer to form the carbon matrix material. Results of the 6-month study are presented herein.

thermal↗
NASA NTRS1961

Flight-Path Characteristics for Decelerating From Supercircular Speed

Characteristics of the following six flight paths for decelerating from a supercircular speed are developed in closed form: constant angle of attack, constant net acceleration, constant altitude" constant free-stream Reynolds number, and "modulated roll." The vehicles were required to remain in or near the atmosphere, and to stay within the aerodynamic capabilities of a vehicle with a maximum lift-drag ratio of 1.0 and within a maximum net acceleration G of 10 g's. The local Reynolds number for all the flight paths for a vehicle with a gross weight of 10,000 pounds and a 600 swept wing was found to be about 0.7 x 10(exp 6). With the assumption of a laminar boundary layer, the heating of the vehicle is studied as a function of type of flight path, initial G load, and initial velocity. The following heating parameters were considered: the distribution of the heating rate over the vehicle, the distribution of the heat per square foot over the vehicle, and the total heat input to the vehicle. The constant G load path at limiting G was found to give the lowest total heat input for a given initial velocity. For a vehicle with a maximum lift-drag ratio of 1.0 and a flight path with a maximum G of 10 g's, entry velocities of twice circular appear thermo- dynamically feasible, and entries at velocities of 2.8 times circular are aerodynamically possible. The predominant heating (about 85 percent) occurs at the leading edge of the vehicle. The total ablated weight for a 10,000-pound-gross-weight vehicle decelerating from an initial velocity of twice circular velocity is estimated to be 5 percent of gross weight. Modifying the constant G load flight path by a constant-angle-of-attack segment through a flight- to circular-velocity ratio of 1.0 gives essentially a "point landing" capability but also results in an increased total heat input to the vehicle.

Luidens, Roger W.↗
DOE OSTI2021

An Upgrade Path for the Fermilab Accelerator Complex

The completion of the PIP-II project and its superconducting linear accelerator will provide up to 1.2 MW of beam power to the LBNF/DUNE facility for neutrino physics. It will also be able to produce high-power beams directly from the linac that can be used for lower-energy particle physics experiments as well, such as directing beam toward the Muon Campus at Fermilab for example. Any further significant upgrade of the beam power to DUNE, however, will be impeded by the limitations of the present Booster synchrotron at the facility. To increase the power to DUNE by a factor of two would require a new accelerator arrangement to feed the Main Injector that does not include the Booster. In what follows, a path toward upgrading the Fermilab accelerator complex to bring the beam power for DUNE to 2.4 MW is presented, using a new rapid-cycling synchrotron plus an energy upgrade to the PIP-II linac. The path includes the ability to instigate a new lower-energy, very high-power beam delivery system for experiments that can address much of the science program presented by the Booster Replacement Science Working Group. It also allows for the future possibility to go beyond 2.4 MW up to roughly 4 MW from the Main Injector.

43 PARTICLE ACCELERATORS↗
NASA NTRS1991

Network of dedicated processors for finding lowest-cost map path

A method and associated apparatus are disclosed for finding the lowest cost path of several variable paths. The paths are comprised of a plurality of linked cost-incurring areas existing between an origin point and a destination point. The method comprises the steps of connecting a purality of nodes together in the manner of the cost-incurring areas; programming each node to have a cost associated therewith corresponding to one of the cost-incurring areas; injecting a signal into one of the nodes representing the origin point; propagating the signal through the plurality of nodes from inputs to outputs; reducing the signal in magnitude at each node as a function of the respective cost of the node; and, starting at one of the nodes representing the destination point and following a path having the least reduction in magnitude of the signal from node to node back to one of the nodes representing the origin point whereby the lowest cost path from the origin point to the destination point is found.

Eberhardt, Silvio P.↗
NASA NTRS2016

Anthropogenic Sulphur Dioxide Load over China as Observed from Different Satellite Sensors

China, with its rapid economic growth and immense exporting power, has been the focus of many studies during this previous decade quantifying its increasing emissions contribution to the Earth's atmosphere. With a population slowly shifting towards enlarged power and purchasing needs, the ceaseless inauguration of new power plants, smelters, refineries and industrial parks leads infallibly to increases in sulphur dioxide, SO2, emissions. The recent capability of next generation algorithms as well as new space-borne instruments to detect anthropogenic SO2 loads has enabled a fast advancement in this field. In the following work, algorithms providing total SO2 columns over China based on SCIAMACHY/Envisat, OMI/Aura and GOME2/MetopA observations are presented. The need for post-processing and gridding of the SO2 fields is further revealed in this work, following the path of previous publications. Further, it is demonstrated that the usage of appropriate statistical tools permits studying parts of the datasets typically excluded, such as the winter months loads. Focusing on actual point sources, such as megacities and known power plant locations, instead of entire provinces, monthly mean time series have been examined in detail. The sharp decline in SO2 emissions in more than 90% - 95% of the locations studied confirms the recent implementation of government desulphurisation legislation; however, locations with increases, even for the previous five years, are also identified. These belong to provinces with emerging economies which are in haste to install power plants and are possibly viewed leniently by the authorities, in favour of growth. The SO2 load seasonality has also been examined in detail with a novel mathematical tool, with 70% of the point sources having a statistically significant annual cycle with highs in winter and lows in summer, following the heating requirements of the Chinese population.

Sulphur dioxide; China; Satellite remote sensing; ↗
DOE OSTI2025

Reactive Carbide‐Based Synthesis and Microstructure of NASICON Sodium Metal All Solid‐State Electrolyte

Reactive carbide precursor-based synthesis of NASICON-type NZSP (Na 1+x Zr 2 Si x P 3-x O 12 ) solid-state electrolyte (SSE) is demonstrated, in contrast to the established oxide-based approach. Exothermic decomposition of ZrC and SiC in air homogenizes microstructure, yielding 98% compact density after conventional sintering at 1200 °C. Quantitative stereology demonstrates that significant microstructural differences are present. Compacts of carbide-derived Carb-NZSP are 98% dense with a secondary zirconium oxide (ZrO 2 ) volume fraction of 0.2% ± 0.3%, versus 93% dense and 3% ± 1% for oxide-derived baseline. For Carb-NZSP, the secondary glassy phosphate phase is agglomerated, while for baseline, it is dispersed and percolated. Electrochemical testing combined with post-mortem analysis demonstrates how microstructural control of secondary phases is critical for dendrite suppression: Carb-NZSP critical current density (CCD) is 3.1 ± 0.8 mA cm −2 at 0.1 mAh cm −2 , versus 1.0 ± 0.7 mA cm −2 at 0.1 mAh cm −2 . Cryogenic focused ion beam (cryo-FIB) analysis demonstrates that in both materials, the porous 2D sheet-like sodium metal dendrites propagate around and subsume NZSP grains, likely following a path enriched with glassy phase and with porosity. Dendrites also flow around isolated zirconia particles. Phase field simulation reveals deflection of dendrites by mechanically tough zirconia, while brittle glassy phase accelerates dendrite growth, especially when finely distributed.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Perovskite Photovoltaic Devices with Carbon-Based Electrodes Withstanding Reverse-Bias Voltages up to –9 V and Surpassing IEC 61215:2016 International Standard

One of the key challenges of perovskite photovoltaics (PV) is the long-term stability. Although efforts are made to improve the lifetime of perovskite PV devices, their degradation under reverse-bias conditions is barely addressed. Herein, perovskite solar cells with carbon-based electrodes are presented which demonstrate superior resilience against reverse-bias-induced degradation. Although their breakdown voltage is identified to be at approximately -3.6 V, cells do not degrade until the applied reverse-bias exceeds -9 V. Two main degradation mechanisms are identified: 1) iodine loss due to hole tunneling into perovskite, which takes place even at low reverse-bias but decomposes the perovskite only after long time durations; and 2) rapid heating at large reverse-bias leading to formation of PbI2, which starts at shunts and then follows the path of the least resistance for the cell current, which is primarily influenced by the electrode sheet resistances. Finally, perovskite solar modules with carbon-based electrodes are demonstrated, which are subjected to a "hotspot" test described in the IEC 61215:2016 international standard at an accredited module testing laboratory. Passing this accelerated test for the first time confirms the superior stability of perovskite PV devices with carbon-based electrodes and highlights their large industrialization potential.

14 SOLAR ENERGY↗
DOE OSTI2023

Potential of the Julia Programming Language for High Energy Physics Computing

Research in high energy physics (HEP) requires huge amounts of computing and storage, putting strong constraints on the code speed and resource usage. To meet these requirements, a compiled high-performance language is typically used; while for physicists, who focus on the application when developing the code, better research productivity pleads for a high-level programming language. A popular approach consists of combining Python, used for the high-level interface, and C++, used for the computing intensive part of the code. A more convenient and efficient approach would be to use a language that provides both high-level programming and high-performance. The Julia programming language, developed at MIT especially to allow the use of a single language in research activities, has followed this path. In this paper the applicability of using the Julia language for HEP research is explored, covering the different aspects that are important for HEP code development: runtime performance, handling of large projects, interface with legacy code, distributed computing, training, and ease of programming. The study shows that the HEP community would benefit from a large scale adoption of this programming language. The HEP-specific foundation libraries that would need to be consolidated are identified.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

Removable coatings: Thermal stability and decontamination of steel surfaces from 241 Am

This study presents a comparative analysis of several strippable materials for decontamination of steel surfaces from 241 Am. The strippable coatings were chosen to have a history of application, to be commercially available, easily handled and have different composition and formulation. Carbon steel and stainless steel surfaces (coupons) were utilized as the most representative industrial materials, and the experimental series were expanded to include the rusting treatment of these surfaces as it is common for decommissioned old nuclear facilities. The experiments followed the path of pre-screening of the strippable materials (easiness of application, peeling etc.), their characterization with Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA), decontamination factors (DF) or removal efficiencies for different types of steel surfaces, and enhancement of the removal efficiencies of the select strippable coatings via amendment with EDTA. As a result, DF and removal efficiencies for stainless steel (both pristine and with rusting treatment) are higher than for pristine carbon steel, and decontamination factors and removal efficiencies are higher for pristine than for rusted carbon steel across all the coatings. It is also shown that EDTA amendment can improve DF and removal efficiency for a strippable coating (i.e., CC Strip), however other factors should also be considered. Thus, the coating CC Strip exhibited easiness in handling and high DF (up to 97% when EDTA-amended), but its drying period was the longest among the rest of the materials and its thermal decomposition indicates on a risk of intense release of heat in case of a fire event.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Substantial Diel Changes of Cloud Adjustments to Aerosols in Ship‐Tracks

Clouds adjust their albedo, amount and liquid water path to anthropogenic aerosols, and produce a climate forcing. Such cloud adjustments are complex functions of both environmental conditions and interaction time. However, direct observations of temporal changes in cloud adjustments are limited. Here, we develop a method to show observational evidence of substantial diel changes in cloud adjustments within ship-tracks. Polluted clouds experiencing extended nighttime exposure exhibit higher increases in cloud fraction while liquid-water path adjustments follow a non-monotonic evolution. The higher cloud fraction increase persists through daytime. Such diel variations likely stem from diel changes in solar heating and background cloud precipitation, and are important because nighttime changes persist and affect solar radiation during the day. Accounting for diel variations produces a stronger aerosol forcing, by −0.1 ∼−0.4 W⁢m −2 . Our approach reveals how the temporal evolution of cloud adjustments can have important implications for aerosol-cloud interactions.

Yuan, Tianle [NASA Goddard Space Flight Center (GS↗
DOE OSTI2022

First-order and gradual phase transitions of ethane confined in MCM-41

The first-order phase transition of ethane confined in MCM-41, i.e., capillary condensation, has been measured using an isochoric cooling procedure by differential scanning calorimetry (DSC) under conditions ranging from 206 K and 1.1 bar up to the pore critical point (PCP). The PCP has also been determined using the three-line method developed earlier based on the vanishing heat of phase transition. As in the bulk phase, no first-order phase transition can occur above the critical point, which also implies that vapor can transform into liquid gradually by following a path around the critical point through the supercritical region. For the first time, the gradual phase transition is demonstrated with ethane in MCM-41, which is achieved through a multistep process with paths proceeding around the PCP without crossing the capillary-condensation curve. Finally, the occurrence of the gradual phase transition in nanopores, thus the confined supercriticality, is confirmed while our consistent DSC measurements are also well demonstrated.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Decay spectroscopy of 160 Eu: Quasiparticle configurations of excited states and structure of K π = 4 + bandheads in 160 Gd

Background: Detailed spectroscopy of neutron-rich, heavy, deformed nuclei is of broad interest for nuclear astrophysics and nuclear structure. Nuclei in the r-process path and following freeze-out region impact the resulting r-process abundance distribution, and the structure of nuclei midshell in both proton and neutron number helps to understand the evolution of subshell gaps and large deformation in these nuclei. Purpose: We aim to improve the understanding of the nuclear structure of 160 Gd, specifically the K π = 4 + bands, as well as study the β decay of 160 Eu into 160 Gd. Methods: High-statistics decay spectroscopy of 160 Gd resulting from the β-decay of 160 Eu was collected using the GRIFFIN spectrometer at the TRIUMF-ISAC facility. Results: Two new excited states and ten new transitions were observed in 160 Gd. The β-decaying half-lives of the low- and high-spin isomers in 160 Eu were determined, and the low-spin state's half-life was measured to be t 1/2 = 26.0 (8) s, ≈ 16% shorter than previous measurements. Lifetimes of the two K π = 4 + bandheads in 160 Gd were measured for the first time, as well as γ – γ angular correlations and mixing ratios of intense transitions out of those bandheads. Conclusions: Lifetimes and mixing ratios suggest that the hexadecapole phonon model of the K π = 4 + bandheads in 160 Gd is preferred over a simple two-state strong mixing scenario, although further theoretical calculations are needed to fully understand these states. Additionally, the 1999.0-keV state in 160 Gd heavily populated in β decay is shown to have positive parity, which raises questions regarding the structure of the high-spin β-decaying state in 160 Eu.

150 ≤ A ≤ 189↗
DOE OSTI2025

ReVise: A Human-AI Interface for Incremental Algorithmic Recourse

The recent adoption of artificial intelligence in socio-technical systems raises concerns about the black-box nature of the resulting decisions in fields such as hiring, finance, admissions, etc. If data subjects—such as job applicants, loan applicants, and students—receive an unfavorable outcome, they may be interested in algorithmic recourse, which involves updating certain features to yield a more favorable result when re-evaluated by algorithmic decision-making. Unfortunately, when individuals do not fully understand the incremental steps needed to change their circumstances, they risk following misguided paths that can lead to significant, long-term adverse consequences. Existing recourse approaches focus exclusively on the final recourse goal but neglect the possible incremental steps to reach the goal with real-life constraints, user preferences, and model artifacts. To address this gap, we formulate a visual analytic workflow for incremental recourse planning in collaboration with AI/ML experts and contribute an interactive visualization interface that helps data subjects efficiently navigate the recourse alternatives and make an informed decision. We also present one of the many usage scenarios, developed during exploratory feedback sessions with twelve graduate students using a real-world dataset, which demonstrates that our approach can be instrumental for data subjects in choosing a suitable recourse path.

algorithmic recourse↗
DOE OSTI2022

Overview of the LANL Multi-Probe Radiography Project [Slides]

Future radiographic facilities for the U.S. defense program will be required to provide more information as simulation codes improve in both physics’ fidelity and resolution. A possible approach is to use more types of probe beams in addition to, or instead of X-rays, generated by 20-MeV electron accelerators from a small number of directions. High power short-pulse laser systems can generate beams of protons, neutrons and electrons, as well as X-rays. The cost of these systems is falling rapidly. So, it can be imagined that deploying multiple short-pulse lasers along with other, more traditional probes, will become feasible. In this project, we are following three paths to determine if such an approach will succeed for cm-scale objects. The first is an experimental one to determine if the presence of multiple short-pulse probes cause interference with each other, especially while radiographing dynamic objects. The second leg of this project is to determine if having multiple types of probes really does give more information on composition. Finally, an overall assessment of the viability of this approach will be made. Examples from recent experiments at the Omega EP laser will be presented. The initial approach to evaluating radiographs with multiple probes using the Bayesian Inference Engine (BIE) also will be given.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Requirements Description of the REBUS Software for the Versatile Test Reactor

This report presents the modeling and simulation capabilities of Argonne National Laboratory’s fuel cycle analysis code, the REactor BUrnup System (REBUS), that will be relied on for the VTR project. These capabilities will then be used to establish the set of REBUS verification tasks necessary to verify REBUS for usage on the VTR project. A similar path was followed for the DIF3D software where its’ requirements and verification tasks were established. REBUS has been maintained by Argonne since the early 1960s to support its reactor design mission. That software transitioned from the original REBUS to REBUS-2 in the mid 1970s and to REBUS-3 in the mid 1980s. Since then REBUS has gone through many revisions to the current REBUS-11. Note that this version numbering is consistent with the progression of DIF3D, the base flux solver that REBUS is built upon. The name REBUS refers to a pictorial based puzzle as the original developers were inspired by having to track thousands of unique fuel assemblies as they are inserted into the reactor, depleted, shuffled, discharged, and reprocessed.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗