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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Pulsed laser deposition of delafossite oxide thin films on YSZ (001) substrates as solar water splitting photocathodes

Development of solar energy converters with earth-abundant and environmentally friendly materials is one of the key routes explored towards a sustainable future. In this work, crystalline delafossite-phase CuAlO 2 and CuFeO 2 thin film solar water splitting photocathodes were fabricated using pulsed laser deposition. It was found that the desired delafossite phase was formed only after high temperature annealing in an oxygen-free atmosphere. Further, the homogeneous delafossite bulk structure of the films was determined by correlating simulation results from first-principles calculations with synchrotron-based X-ray absorption near edge structure (XANES) spectroscopy. Both CuAlO 2 and CuFeO 2 photocathodes are active for solar water splitting, with the latter more efficient due to its narrower band gap and improved light absorption.

36 MATERIALS SCIENCE↗
NASA NTRS2013

Development of Large-Scale Spacecraft Fire Safety Experiments

The status is presented of a spacecraft fire safety research project that is under development to reduce the uncertainty and risk in the design of spacecraft fire safety systems by testing at nearly full scale in low-gravity. Future crewed missions are expected to be more complex and longer in duration than previous exploration missions outside of low-earth orbit. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low-gravity, the need for realistic scale testing at reduced gravity has been demonstrated. To address this gap in knowledge, a project has been established under the NASA Advanced Exploration Systems Program under the Human Exploration and Operations Mission directorate with the goal of substantially advancing our understanding of the spacecraft fire safety risk. Associated with the project is an international topical team of fire experts from other space agencies who conduct research that is integrated into the overall experiment design. The experiments are under development to be conducted in an Orbital Science Corporation Cygnus vehicle after it has undocked from the ISS. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew removes the need for strict containment of combustion products. The tests will be fully automated with the data downlinked at the conclusion of the test before the Cygnus vehicle reenters the atmosphere. A computer modeling effort will complement the experimental effort. The international topical team is collaborating with the NASA team in the definition of the experiment requirements and performing supporting analysis, experimentation and technology development. The status of the overall experiment and the associated international technology development efforts are summarized.

Life Support↗
DOE OSTI2025

Materials Engineering for High Performance and Durability Proton Exchange Membrane Water Electrolyzers

Proton exchange membrane water electrolyzers (PEMWEs) are expected to play a crucial role in the global green energy transition during the 21st century. They provide a versatile and sustainable solution for generating hydrogen with very high purity in combination with renewable energies, such as solar and wind. Despite their promise, PEMWEs face several critical problems, including high costs, performance limitations, and durability challenges, particularly at low iridium (Ir) loading on the anode. Advancing next-generation PEMWEs requires extensive work on materials engineering of all cell components, including the catalyst layer (CL), membrane, porous transport layer (PTL), bipolar plate (BPP), and gasket. This task must be performed with the complementary contribution of different modeling and characterization techniques. This review presents a critical perspective from academia, research centers, and industry, mapping main developments, remaining gaps, and strategic pathways to advance PEMWE technology. A focus is devoted to key aspects, such as operation at low Ir loading, membrane durability, multiscale transport layers, porous and non-porous flow fields, multiphysics modeling, and multipurpose characterization techniques, which are thoroughly discussed. By unifying these topics, this review provides readers with the essential knowledge to grasp current developments and tackle tomorrow's challenges in PEMWE engineering.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Using Membranes with Internal Microchannels to Prevent Drying-out during CO 2 Electrolysis

Scaling up CO 2 electrolysis is a vital aspect in the transition to manufacturing sustainable fuels and chemical compounds, satisfying the demand for chemicals and demand for storing renewable electricity. Depending on the employed catalyst, different products can be produced, such as carbon monoxide and ethylene, by applying a voltage on a CO 2 and H 2 O fed electrolyzer. CO is a desirable product according to techno-economic analysis, because it can be produced selectively using a silver catalyst and is a precursor for hydrocarbons in the Fischer–Tropsch process. In a state-of-the-art CO 2 electrolyzer, two electrodes are directly pressed against an ion-exchange membrane – this is called a zero-gap configuration. Therefore, the membrane is a crucial component for the system, since it has the role of providing a conductive medium between the electrodes. One of the challenges in CO 2 electrolysis is that water is consumed in the reaction. At high current density, this may cause the membrane's surface near the cathode to dry out, lowering efficiency or perhaps stopping the process entirely, since there is no longer a conductive medium. As a result, water management is critical for this process. In this work, we approach the drying-out challenge by studying the novel concept of a membrane with internal microchannels. These channels allow the circulation of water or an electrolyte inside the membrane, which reduces the water diffusion path and affects the membrane’s conductivity. The effects of channel geometry, location, and concentrations of electrolyte inside on water content, conductivity and overall performance are studied in a 2D COMSOL model. In addition, the effect of internal concentration of electrolyte on the membrane’s resistance, on the process performance and the K + cross-over to cathode side were investigated experimentally. Our modeling results prove that the presence of the channels can keep the membrane hydrated. The highest current densities are observed when the channel is closest to the cathode, and with smaller pores. Smaller pores are advantageous due to the trade-off between enhanced membrane conductivity and the lower conductivity of the liquid itself. If water is circulated in a large channel, it increases the membrane’s ionomer conductivity due to hydration but the overall conductivity is decreased since water is not highly conductive. Nonetheless, the results also show that a higher concentration of electrolyte inside the microchannels can significantly increase the total conductivity of the membrane, and therefore the energy efficiency of the process. These effects are most significant at higher current densities. In the experimental results, we’ve observed similar effects in terms of membrane conductivity and current density of the process – the higher the electrolyte concentration the higher the current density. Furthermore, a low concentration decreases the amount of potassium which crosses over to the cathode side, inhibiting salt deposition. We’ve concluded that a small channel, up to 90 µm wide, close to the pore with an electrolyte with a concentration of up to 10 mM could be very beneficial for the water management and energy efficiency of the process. This helps to keep the membrane hydrated at higher current densities, improves the conductivity of the membrane, and it doesn’t have significant impacts on the salt deposition.

Petrov, Kostadin Veselinov↗
DOE OSTI2021

Benefits and Critical Knowledge Gaps in Determining the Role of Floating Photovoltaics in the Energy-Water-Food Nexus

Floating solar photovoltaic (FPV) systems have become an increasingly attractive application of photovoltaics (PV) because of land-use constraints, the cost of land and site preparation, and the perceived energy and environmental co-benefits. Despite the increasing interest in FPV systems, a robust validation of their suggested co-benefits and impacts on the nexus of energy, water, and food (EWF) systems is lacking. This information gap makes it challenging for decision makers to justify its adoption—potentially suppressing FPV deployment. To address this gap and to help de-risk this PV deployment opportunity, we (1) review the suggested co-benefits of FPV systems with a focus on the impacts that could alleviate pressures on EWF systems and (2) identify areas where further research is needed to reduce uncertainty around FPV system performance. Our review reveals that EWF nexus-relevant co-benefits, such as improved panel efficiency and reduced land usage, are corroborated in the literature, whereas others, such as water quality impacts, lack empirical evidence. Our findings indicate that further research is needed to quantify the water-related and broader economic, environmental, social, sustainability, justice, and resilience co-benefits and impacts of FPV systems.

14 SOLAR ENERGY↗
NASA NTRS2004

Developing a Simulation-Based Training Program for Non-Traditional Caregivers

Simulation-based training enables learning in controlled environments which nevertheless mimic real-world scenarios. It has proven effective in the training of medical personnel and affords rapid assimilation and integration of necessary skills. Non-traditional caregivers often operate in austere environments, where resource and personnel limitations preclude more standard provision of care by highly trained and fully equipped health care teams. In these settings, training time for the caregivers may be limited, with long gaps between time of the training and use of the skills, a limited grasp of the underlying physiology, and unfamiliarity with "medical English" which can render it difficult to communicate concepts to more advanced practitioners when such interaction can take place, as for example, when telemedicine can be used to project medical skills further forward . Methods: Simulation-based training can assist in the familiarization of caregivers to the environment, ensure adequate execution of skills at the appropriate time(s), and allow practice of telemedicine communication patterns between the mentor and caregiver. Results: Scenario-based training can and has been used for initial and sustainment training modules, including self-taught modules for use in the field. Strict identification of the critical concepts is vital, as is development and practice of technically simple procedures wherever possible. Medical devices can off-load tasks from caregivers, as well as to minimize the necessary level of caregiver knowledge, while integrated simulations among all members of the mission team can improve communication and efficiency. Discuss ion: Nontraditional caregivers face unique challenges when learning to provide medical care. Scenario-based curricula allow lesson plans to be tailored to each group's individual needs, as well as being suited for the participation of numerous groups, including the caregiver, evacuation/transport staff, decision-makers, and hospital-based physician.

Bacal, Kira↗
DOE OSTI2021

Advancing Electrolyte Solution Chemistry and Interfacial Electrochemistry of Divalent Metal Batteries

Divalent metal (Mg, Ca, etc.) battery chemistries potentially provide a sustainable long-term technical solution for large-scale energy storage because of high natural abundance of divalent metal elements in the earth crust. Good progress has been made on materials especially electrolyte development in the past years; however, significant challenges exist, particularly the very limited fundamental understanding on electrolyte solution chemistry and interfacial electrochemistry. In this perspective, we review and discuss key discoveries and understanding of divalent battery chemistry with a focus on electrolyte-dependent interfacial electrochemistry of divalent metal anodes. A concise review of electrolyte development, operando studies of the electrified interfaces and unique charge-transfer process is provided; the knowledge gaps and future research directions are discussed.

25 ENERGY STORAGE↗
DOE OSTI2025

Geologic hydrogen: From natural occurrences to anthropogenic generation – A review of fundamentals, potential, challenges and prospects

Growing demand for hydrogen is exposing the environmental and economic limits of reforming-based and carbon-managed supply chains, while the scale-up of electrolytic capacity remains capital-constrained. Geologic hydrogen, defined as molecular H₂ generated and stored within the Earth's crust offers a complementary, potentially lower-cost resource, yet exploration is still ad hoc. This review (1) revisits a global inventory of confirmed hydrogen seeps and subsurface occurrences; (2) analyzes the controlling reactions, migration pathways, and trapping conditions governing these occurrences; (3) proposes a process-based geologic hydrogen system concept analogous to, yet distinct from, the petroleum system; and (4) evaluates potential geologic hydrogen systems within the United States as a representative case study. Here, we contrast natural systems powered by serpentinization, mantle degassing or radiolysis with anthropogenic systems that stimulate the same reactions or convert in-situ hydrocarbons. Stable hydrogen accumulations require generation rates that outpace combined physical, chemical and microbial losses; the Bourakébougou field (Mali) exemplifies a self-recharging, free-gas reservoir sustained by meteoric-water serpentinization beneath an efficient caprock. Prospective geologic hydrogen resources are likely to occur in regions where iron-rich lithologies, deep-seated faults, and low-permeability sealing formations coexist. Applying this principle, we highlight three promising hydrogen play types in U.S. geological terrains: ophiolite belts (Appalachian and Californian regions), the Midcontinent Rift and the Lake Superior banded‑iron formations. Multiphysics numerical models and positive-unlabeled machine-learning workflows help to accelerate play screening and de-risk future production; yet, reaction kinetics, stimulation strategies, and full techno-economic and life-cycle assessments remain pivotal knowledge gaps.

Anthropogenic hydrogen generation↗
DOE OSTI2025

Technology Case Study: Economic, Sustainability, and Deployment Considerations for Sustainable Aviation Fuels Produced via Lignocellulosic Sugar Catalysis

This report presents a technology case study reflecting one exemplary representative pathway for the conversion of lignocellulosic sugars to sustainable aviation fuels (SAF) via aqueous phase reforming (APR) catalysis, considered within a broader integrated biorefinery framework based on biochemical processing operations. While far from the only option for converting sugars to SAF, this pathway was selected as a case study here based on its relatively high technology maturity and simplistic processing approach (avoiding complex separations or other equipment scalability challenges), coupled with the potential for high fuel yields and favorable costs/carbon intensities with opportunities for further near-term optimization. The report considers key process integration and engineering design considerations for a modeled hypothetical, nth-plant commercial biorefinery, reflecting a number of processing options and parameters envisioned to be achievable as future goals. Resultant outputs from Aspen Plus process simulations are evaluated through techno-economic and life cycle analyses (TEA and LCA), including implications for marginal cost of CO2 abatement and inclusion of currently-applicable policy incentives. Moving beyond base case configurations, a number of alternative scenarios are also evaluated for their ability to further improve economics, greenhouse gas (GHG) emissions, and marginal cost of abatement, highlighting a path to achieve deep decarbonization goals of more than 70% GHG reduction for SAF (with the potential to reach net-negative carbon intensities in some cases) under reasonable fuel production costs. The report also highlights future opportunities and gaps for further research on this technology pathway.

09 BIOMASS FUELS↗
DOE OSTI2020

Surface Josephson plasma waves in a high-temperature superconductor

Abstract Electron density oscillations with acoustic dispersions and sustained at boundaries between different media provide information about surface and interface properties of heterostructures. In ultrathin metallic films these plasmonic excitations are heavily damped. Superconductivity is predicted to reduce dissipation allowing detection of these resonances. Emerging low-loss interface Cooper-pair waves have been studied before, however, the observation of surface-confined Josephson plasmons in highly anisotropic superconductors has remained elusive. Here, we report on generation and coupling to these excitations in an ultrathin single-crystal film of high-temperature superconductor La 1.85 Sr 0.15 CuO 4 . The film becomes brighter than Au below the critical temperature when probed with sub-gap THz photons. We show that the enhanced signal in the superconducting state, which can be visualized with a spatial resolution better than λ/3000, originates from near-field coupling of light to surface Josephson plasmons. Our results open a path towards non-invasive investigation of enhanced superconductivity in artificial multilayers, buried interface states in topological heterostructures, and non-linear phenomena in Josephson devices.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

Vortex-Controlled Quasiparticle Multiplication and Self-Growth Dynamics in Superconducting Resonators

Even in the quantum limit, non-equilibrium quasiparticle (QP) populations induce QP poisoning that irreversibly relaxes the quantum state and significantly degrades the coherence of transmon qubits. A particularly detrimental yet previously unexplored mechanism arises from QP multiplication facilitated by vortex trapping in superconducting quantum circuits, where a high-energy QP relaxes by breaking additional Cooper pairs and amplifying the QP population due to the locally reduced excitation gap and enhanced quantum confinement within the vortex core. Here we directly resolve this elusive QP multiplication process by revealing vortex-controlled QP self-generation in a highly nonequilibrium regime preceding the phonon bottleneck of QP relaxation. At sufficiently low fluence, femtosecond-resolved magneto-reflection spectroscopy directly reveals a continuously increasing QP population that is strongly dependent on magnetic-field-tuned vortex density and absent at higher excitation fluences. Quantitative analysis of the emergent QP pre-bottleneck dynamics further reveals that, although the phonon population saturates within $\simeq$10~ps, both free and trapped QPs continue to grow in a self-sustained manner--hallmarks of the long-anticipated QP-vortex interactions in nonequilibrium superconductivity. We estimate a substantial increase of $\sim$34% in QP density at vortex densities of $\sim$ 100 magnetic flux quanta per $\mathrm{μm^{2}}$. Our findings establish a powerful spectroscopic tool for uncovering QP multiplication and reveal vortex-assisted QP relaxation as a critical materials bottleneck whose mitigation will be essential for resolving QP poisoning and enhancing coherence in superconducting qubits.

Park, Joong M. [Ames Lab]↗
NASA NTRSDate not supplied

Recent Discoveries in Simulant Behavior and Regolith Handling

The past few years have seen an exciting increase in visibility for the use of in-situ resources to achieve sustainability at the Moon and Mars. This visibility and inclusion in the mission architectures has led to an explosion in the research and development of mining and processing of regolith at the Moon. However, there are still many fundamental issues regarding digging, transporting, and processing of lunar and Mars regolith that may slow the progress by multiple teams who need to understand these issues before proceeding with hardware development. The objective of this project is to utilize the same team of soil and thermal experts and unique facilities to allow for efficient and fast generation of fundamental data and dissemination of critical results to the larger community. The capability gaps being addressed include how to dig up hard, frozen resources, transport to the processing site, lifting/depositing into a hopper or reactor, and extracting the water, all without losing the primary product to the environment. Soil Seals: Much attention has been focused on the challenges with regolith inlet/outlet valves that must seal in process gases after being repeatedly ex-posed to abrasive regolith and dust particles. One possible solution that has been proposed is to design the inlet hopper or duct such that the bulk of regolith pro-vides sufficient sealing of the reactor. Tests are planned to parametrically measure the maximum del-ta-pressure that can be maintained across a column of soil before ‘blow-out’ occurs. Variables to be examined include column height and width, simulant type, and compaction.

Simulant↗
DOE OSTI2025

Challenges in Tracking Waste Reduction Performance Improvement in Manufacturing Plants

The recently released Circularity Gap Report 2023 by the Circle Economy Foundation states that the circularity score for the global economy is declining. The US Environmental Protection Agency (EPA) tracked municipal solid waste from 1960 to 2018 and found that 50% of the waste was destined for landfills. EPA estimates that US industry is responsible for 2.7 Gt of solid nonhazardous waste annually in the US mostly linear economy model. The circular economy framework aims to decouple economic value generation from the extraction of virgin materials from nature. The linear model of material extraction and disposal at the end of life is highly unsustainable. Manufacturing companies are adopting ambitious waste reduction targets to achieve sustainability. Through the Better Plants program, US DOE has established the Waste Reduction Network, which offers technical assistance to partners to achieve their ambitious waste reduction goals. Basic requirements of establishing a target include identifying a baseline, quantifying waste performance, and measuring progress over time. One problem faced by industry is unstandardized metrics for quantifying waste performance that may not be well suited to demonstrate progress. This paper studies traditional methods used to measure waste performance and highlights advantages, disadvantages, and limitations of each method. It also examines the suitability of applying the methods in different manufacturing circumstances. Finally, the paper presents a case study of a large manufacturer that faced inconsistencies in its tracked measurement metric. A solution was proposed and implemented to alter the methodology to enable more accurate waste performance tracking against a baseline.

circular economy↗
DOE OSTI2023

Technical Specification Surveillance Interval Extension Using Self-Diagnostics

As part of the Light Water Reactor Sustainability program, an ongoing research effort is being conducted on technical specifications surveillance interval extension of digital equipment in nuclear power plants. The research team is led by Idaho National Laboratory and includes Pacific Northwest National Laboratory, Technology Resources, and Oak Ridge National Laboratory. This research focuses on developing methods for applying the U.S. Nuclear Regulatory Commission (NRC)–approved guidance to implement a licensee-controlled, risk-informed surveillance frequency change program in digital instrumentation and control (I&C) systems that include self-diagnostics and online monitoring (OLM) capabilities. Although approved methods exist for extending technical specifications (TS) surveillance test intervals (STIs) for general equipment, including analog I&C equipment, gaps remain in technology and guidance on crediting newer digital equipment’s internal self-diagnostics and OLM characteristics. Previous research described a general methodology for crediting internal self-diagnostics for extending surveillance test intervals. The methodology used self-diagnostics to detect—and credited recovery from—failure. Self-diagnostics were also applied for performance monitoring during the extended surveillance interval. This report discusses the status of recent activities to evaluate the previously developed methodology using a pilot study. Although both a utility partner for a pilot study and a specific digital asset were identified in FY2020, delays in obtaining proprietary information resulted in a limited ability to fully evaluate the methodology, and further interactions were complicated by the COVID pandemic. Therefore, at that time, the use of public-domain information—along with current processes for surveillance interval extension through a surveillance frequency control program—identified the need to fully assess diagnostic coverage as part of the pilot study. Furthermore, self-diagnostics were also identified as a potential option to replace the drift analyses conducted as part of current STI extension procedures. In FY2022, the project was reconstituted with the industry partner, and information and data were made available by the industry partner to the research team for review. The shared information included failure event descriptions and data for a digital I&C system since its implementation, as well as recent STI extension interval reports developed by the utility partner on that digital I&C system. This report presents an evaluation of this information and data and describes an application of the proposed methodology cited above. The methodology seeks to take advantage of the self-diagnostics and OLM capabilities to reduce risk or reduce the level of qualitative monitoring assessment needed to perform a risk-informed STI extension using existing NRC approved guidance or both. Addressing these issues of STI extension by crediting self-diagnostics is likely to result in benefits for current and future nuclear power plant (NPP) operations, including lowering the barriers to adoption of digital I&C systems and increasing cost savings by deferring or eliminating unneeded preventive maintenance (tasks or checks or activities). Specifically, self-diagnostic and OLM capabilities of newer digital equipment being installed in non-safety and safety applications are designed to detect failures, provide early warning of potential failures, and notify plant operators to take appropriate action to reduce out of service (OOS) time thus protecting safety margins. Moreover, the equipment is expected to provide information that time-related operational degradation is identified early to ensure timely and planned corrective actions instead of a reactive and unplanned approach ahead of an extended-surveillance interval.

42 ENGINEERING↗
NASA NTRS2006

Domed, 40-cm-Diameter Ion Optics for an Ion Thruster

Improved accelerator and screen grids for an ion accelerator have been designed and tested in a continuing effort to increase the sustainable power and thrust at the high end of the accelerator throttling range. The accelerator and screen grids are undergoing development for intended use as NASA s Evolutionary Xenon Thruster (NEXT) a spacecraft thruster that would have an input-power throttling range of 1.2 to 6.9 kW. The improved accelerator and screen grids could also be incorporated into ion accelerators used in such industrial processes as ion implantation and ion milling. NEXT is a successor to the NASA Solar Electric Propulsion Technology Application Readiness (NSTAR) thruster - a state-of-the-art ion thruster characterized by, among other things, a beam-extraction diameter of 28 cm, a span-to-gap ratio (defined as this diameter divided by the distance between the grids) of about 430, and a rated peak input power of 2.3 kW. To enable the NEXT thruster to operate at the required higher peak power, the beam-extraction diameter was increased to 40 cm almost doubling the beam-extraction area over that of NSTAR (see figure). The span-to-gap ratio was increased to 600 to enable throttling to the low end of the required input-power range. The geometry of the apertures in the grids was selected on the basis of experience in the use of grids of similar geometry in the NSTAR thruster. Characteristics of the aperture geometry include a high open-area fraction in the screen grid to reduce discharge losses and a low open-area fraction in the accelerator grid to reduce losses of electrically neutral gas atoms or molecules. The NEXT accelerator grid was made thicker than that of the NSTAR to make more material available for erosion, thereby increasing the service life and, hence, the total impulse. The NEXT grids are made of molybdenum, which was chosen because its combination of high strength and low thermal expansion helps to minimize thermally and inertially induced deflections of the grids. A secondary reason for choosing molybdenum is the availability of a large database for this material. To keep development costs low, the NEXT grids have been fabricated by the same techniques used to fabricate the NSTAR grids. In tests, the NEXT ion optics have been found to outperform the NSTAR ion optics, as expected.

Soulas, George C.↗
DOE OSTI2023

Human and Technology Integration Evaluation of Advanced Automation and Data Visualization

While the existing United States (U.S.) light water reactors are highly reliable, safe, and provide a significant proportion of carbon-free electricity, the cost of operating and maintaining them has become less competitive compared to other electricity generating sources. The reason for the gap in operating and maintenance (O&M) costs can be at least in part attributed to the advent of new digital technologies that other electricity generating industries are currently using. Advanced capabilities including digital instrumentation and control (I&C) systems, advanced automation and analytics, and greater span of data integration (i.e., connectedness) across these non-nuclear plants has transformed the way work is performed and ultimately given them a competitive advantage in terms of the cost required for operating, maintaining, and supporting them. To reduce O&M cost and address obsolescence of the aging I&C infrastructure of the existing U.S. light water reactors, the U.S. Department of Energy (DOE) Light Water Reactor Sustainability (LWRS) Program Plant Modernization Pathway is conducting targeting multidisciplinary research that 1) delivers a sustainable business model to enable a cost-competitive U.S. nuclear industry and 2) is developing technology modernization solutions that address aging and obsolescence challenges. The work described in this report supports these two objectives and describes the demonstration of human and technology integration across recent industry collaborations to support their large-scale digital I&C modifications. This technical report describes the demonstration of the human and technology integration methodology in performing full-scale performance-based human-in-the-loop tests to evaluate plant-specific advanced automation and data visualization applications within these collaborators’ digital modifications. This technical report also documents future applications of human and technology integration that expand beyond main control room modernization and digital I&C upgrades, which have been a central focus to date. Thus, this technical report discusses how to implement human and technology integration across new business opportunities and how to develop an evaluation plan that defines measures and criteria, and documents key assumptions to support full plant modernization.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2021

R -mode Stability of GW190814's Secondary Component as a Supermassive and Superfast Pulsar

The nature of GW190814's secondary component m 2 of mass (2.50–2.67)M ⊙ in the mass gap between the currently known maximum mass of neutron stars and the minimum mass of black holes is currently under hot debate. Among the many possibilities proposed in the literature, the m 2 was suggested as a superfast pulsar while its r-mode stability against the run-away gravitational radiation through the Chandrasekhar-Friedman-Schutz mechanism is still unknown. Previously, Fortin et al. constructed a sample of 33 unified equations of state using the same nuclear interactions from the crust to the core consistently; from that sample we use those equations that fulfill all currently known astrophysical and nuclear physics constraints to compare the minimum frequency required for m 2 to rotationally sustain a mass greater than 2.50 M ⊙ with the critical frequency above which the r-mode instability occurs. Here, we use two extreme damping models assuming that the crust is either perfectly rigid or elastic. Using the stability of 19 observed low-mass X-ray binaries as an indication that the rigid crust damping of the r-mode dominates within the models studied, we find that m 2 is r-mode-stable while rotating with a frequency higher than 870.2 Hz (0.744 times its Kepler frequency of 1169.6 Hz) as long as its temperature is lower than about 3.9 × 10 7 K, further supporting the proposal that GW190814's secondary component is a supermassive and superfast pulsar.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2023

Selective Valorization of CO 2 towards Valuable Hydrocarbons through Methanol-mediated Tandem Catalysis

The thermocatalytic conversion of carbon dioxide (CO 2 ) into valuable hydrocarbons presents a promising solution for mitigating anthropogenic CO 2 emissions while producing drop-in replacements for fossil-derived products. Among the two tandem mechanisms for the direct hydrogenation of CO 2 , the methanol synthesis coupled with the methanol to hydrocarbon (MTH) reaction offers an improvement over the reverse water-gas shift coupled with Fischer-Tropsch synthesis reaction (RWGS-FTS), as it is not limited by Anderson-Schulz-Flory distribution and yields higher selectivity towards specific products (e.g., olefins, aromatics, higher hydrocarbons). Herein, we focus on the recent progress achieved through this pathway and outline the existing knowledge gaps. We discuss the challenges involved in the process and highlight the key descriptors in the selection of catalyst components. Finally, we present several potential solutions to circumvent the current challenges, aiming to expedite the advancement of this route toward an efficient CO 2 hydrogenation process.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗