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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 415 records · Page 23

Electrochemical Reduction Pathways from Goethite to Green Iron in Alkaline Solution with Silicate Additive

Energy-efficient and low-temperature iron electrolysis in alkaline solutions is a low-cost and sustainable ironmaking process with zero-carbon emissions when renewable electrical sources are involved. However, its implementation is hindered by electrochemically inert Fe 3 O 4 and parasitic H 2 gas formation during the electrochemical reduction process, resulting in the low energy efficiency of iron electrolysis. Here, we further explore the potential of electrochemical reduction of goethite (FeOOH) by employing a low concentration of silicate additive in an alkaline solution to mitigate Fe 3 O 4 accumulation and H 2 generation. Electrochemical measurements coupled with operando X-ray diffraction and X-ray absorption spectroscopy suggested FeOOH → Fe 3 O 4 → Fe(OH) 2 → Fe reduction pathways. Interestingly, a poorly crystalline or amorphous Fe(OH) 2 phase formed in the NaOH/silicate mixed electrolyte, possibly due to the inhibitive effect of silicate on water and ion transport, which eventually contributed to the improved reduction of Fe 3 O 4 , also supported by atomistic simulations. This work demonstrates the potential for silicate as a low-cost and effective electrolyte additive to improve room-temperature green iron formation via electrolysis.

36 MATERIALS SCIENCE↗

Efficient conversion of low-concentration nitrate sources into ammonia on a Ru-dispersed Cu nanowire electrocatalyst

We report electrochemically converting nitrate ions, a widely distributed nitrogen source in industrial wastewater and polluted groundwater, into ammonia represents a sustainable route for both wastewater treatment and ammonia generation. However, it is currently hindered by low catalytic activities, especially under low nitrate concentrations. Here we report a high-performance Ru-dispersed Cu nanowire catalyst that delivers an industrial-relevant nitrate reduction current of 1 A cm –2 while maintaining a high NH 3 Faradaic efficiency of 93%. More importantly, this high nitrate-reduction catalytic activity enables over a 99% nitrate conversion into ammonia, from an industrial wastewater level of 2,000 ppm to a drinkable water level <50 ppm, while still maintaining an over 90% Faradaic efficiency. Coupling the nitrate reduction effluent stream with an air stripping process, we successfully obtained high purity solid NH 4 Cl and liquid NH 3 solution products, which suggests a practical approach to convert wastewater nitrate into valuable ammonia products. Density functional theory calculations reveal that the highly dispersed Ru atoms provide active nitrate reduction sites and the surrounding Cu sites can suppress the main side reaction, the hydrogen evolution reaction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

FLASH-therapy suitable single-pulse proton generation using TiH 2 under nanosecond laser irradiation

We investigated proton emission from titanium hydride (TiH 2 ) targets irradiated in vacuum by a 6-ns, 1064-nm Nd:YAG laser. Time-of-flight measurements with a Faraday cup and an electrostatic ion analyzer resolved distinct proton peaks at high pulse energies, with yields on the order of 10 9 protons per shot. Systematic scans over pulse energy and up to 1000 repeated shots showed that, while the peak amplitude gradually decreased, the integrated proton number remained nearly constant. This behavior is consistent with surface-induced broadening of the plasma expansion while bulk hydrogen is replenished by diffusion and repeated ablation of fresh TiH 2 layers. Using the measured proton numbers and pulse widths, a simple direct-plasma-injection-style scaling indicates peak currents of ∼100 mA and sub-microsecond pulse durations. The pulse structure and yield satisfy key ultra-high-dose-rate criteria and, together with sustained output over 1000 shots, support TiH 2 -based laser ion sources as practical candidates for FLASH-therapy (ultra-high-dose-rate)-oriented studies and injector development using direct plasma injection.

43 PARTICLE ACCELERATORS↗

Ultraselective sequestration of Li + and Mg 2+ from brines via a reusable polyoxoniobate-based ion sponge

Lithium (Li) and magnesium (Mg) are designated as critical mineral materials (CMM) due to their essential roles in clean energy technologies. However, extracting high-purity Li + from brine remains a formidable challenge owing to the presence of Mg 2+ , a physicochemical similar ion that often exists in excess. Here, we introduce a polyoxoniobate-based “Mg-PONb sponge” that enables ultraselective and rapid Li + /Mg 2+ separation across an exceptionally broad range of Mg/Li ratios (0.02 to 200.63). This framework achieves >99.9% Mg 2+ removal with negligible Li + loss in under 1 min, yielding Li + /Mg 2+ selectivity values exceeding 5000. The sponge demonstrates excellent recyclability, maintaining >99% Mg 2+ rejection and Li + permeability across five regeneration cycles without structural degradation. Mechanistic investigations reveal that selective Mg 2+ capture originates from strong coordination with terminal oxygens on the PONb cluster, driving rapid formation of porous Mg-PONb frameworks. This work presents a generalizable, scalable strategy for Li + /Mg 2+ separation and offers a sustainable path toward enhanced Li and Mg recovery from complex brine sources.

Chen, Linfeng [Lawrence Berkeley National Laborato↗

Terephthalic Acid Synthesis from Ethanol via p-Methyl Benzaldehyde

Terephthalic acid (TA) is a high volume and high market commodity chemical which is a monomer used in making polyethylene terephthalate (known as PET) for beverage bottles and packaging films. The global demand for TA in 2012 was 47 million ton and it is expected to grow at a 6 percent rate to reach around 65 million ton in 2018. TA is currently made from petroleum derived p-xylene produced as a co-product during ethylene production in the naphtha cracking process. At present, ethylene is mostly made by ethane cracking of cheap natural gas-shale gas, making naphtha cracking to produce p-xylene uneconomical. Combined with potential unavailability of the petroleum based p-xylene to meet market demand and the end user’s interest in sustainable PET products has created significant attention towards biomass based feed sources for the TA production. The goal of the proposed work is to develop a catalytic process from a biomass-sourced feedstock to a chemical intermediate that can serve as the basis for the economical and renewable TA production that meets market needs.

02 PETROLEUM↗

The 2GCHAS: A high productivity software development environment

To the user, the most visible feature of the Transportable Applications Executive (TAE) is its very powerful user interface. To the programmer, TAE's user interface, proc concept, standardized interface definitions, and hierarchy search provide a set of tools for rapidly prototyping or developing production software. The 2GCHAS (Second Generation Comprehensive Helicopter Analysis System) project has extended and enhanced these mechanisms, creating a powerful and high productivity programming environment where the 2GCHAS development environment is 2GCHAS itself and where a sustained rate for certified, documented, and tested software above 30 delivered source instructions per programmer day has been achieved. The 2GCHAS environment is not limited to helicopter analysis, but is applicable to other disciplines where software development is important.

Babb, Larry↗

A dynamic model of stress and sustained attention

This paper examines the effects of stress on sustained attention. With recognition of the task itself as the major source of cognitive stress, a dynamic model is presented that addresses the effects of stress on vigilance and, potentially, a wide variety of attention performance tasks.

Review↗

Optimization of a Nafion Membrane-Based System for Removal of Chloride and Fluoride from Lunar Regolith-Derived Water

A long-term human presence in space will require self-sustaining systems capable of producing oxygen and potable water from extraterrestrial sources. Oxygen can be extracted from lunar regolith, and water contaminated with hydrochloric and hydrofluoric acids is produced as an intermediate in this process. We investigated the ability of Nafion proton exchange membranes to remove hydrochloric and hydrofluoric acids from water. The effect of membrane thickness, product stream flow rate, and acid solution temperature and concentration on water flux, acid rejection, and water and acid activity were studied. The conditions that maximized water transport and acid rejection while minimizing resource usage were determined by calculating a figure of merit. Water permeation is highest at high solution temperature and product stream flow rate across thin membranes, while chloride and fluoride permeation are lowest at low acid solution temperature and concentration across thin membranes. The figure of merit varies depending on the starting acid concentration; at low concentration, the figure of merit is highest across a thin membrane, while at high concentration, the figure of merit is highest at low solution temperature. In all cases, the figure of merit increases with increasing product stream flow rate.

Anthony, Stephen M.↗

Production of Methane and Water from Crew Plastic Waste

Recycling is a technology that will be key to creating a self sustaining lunar outpost. The plastics used for food packaging provide a source of material that could be recycled to produce water and methane. The recycling of these plastics will require some additional resources that will affect the initial estimate of starting materials that will have to be transported from earth, mainly oxygen, energy and mass. These requirements will vary depending on the recycling conditions. The degredation products of these plastics will vary under different atmospheric conditions. An estimate of the the production rate of methane and water using typical ISRU processes along with the plastic recycling will be presented.

Captain, Janine↗

Structural Sizing of a 50-m-Tall Thermoplastic Composite Solar Array Truss Tower Structure for the Lunar South Pole

At the lunar south pole, solar arrays elevated by truss towers are exposed to near continuous sunlight since the sun remains near the horizon. Recent studies suggest that tower heights on the order of 50 m are needed to meet the power requirements to support a sustained lunar presence. While eventually towers may be constructed using materials sourced in-situ, initially structural elements will likely be brought from the Earth, deployed, and assembled. Thermoplastic composites offer the benefit of high specific stiffness and strength properties along with welding for assembly joints, and therefore represent a promising material system for this application. The focus of this paper is on the structural sizing of such towers. A set of expressions based on beam theory are presented for preliminary sizing of the truss tower structure for strength and buckling. The loading condition that drives sizing is base excitation resulting from moonquakes. A point design, developed through finite element analysis, verifies the analytical sizing routine and shows the importance of joints. The results show a viable point design and highlight the factors most significant in the structural sizing.

Thermoplastic composites↗

Structural Sizing of a 50-m-Tall Thermoplastic Composite Solar Array Truss Tower Structure for the Lunar South Pole

At the lunar south pole, solar arrays elevated by truss towers are exposed to near continuous sunlight since the sun remains near the horizon. Recent studies suggest that tower heights on the order of 50 m are needed to meet the power requirements to support a sustained lunar presence. While eventually towers may be constructed using materials sourced in-situ, initially structural elements will likely be brought from the Earth, deployed, and assembled. Thermoplastic composites offer the benefit of high specific stiffness and strength properties along with welding for assembly joints, and therefore represent a promising material system for this application. The focus of this paper is on the structural sizing of such towers. A set of expressions based on beam theory are presented for preliminary sizing of the truss tower structure for strength and buckling. The loading condition that drives sizing is base excitation resulting from moonquakes. A point design, developed through finite element analysis, verifies the analytical sizing routine and shows the importance of joints. The results show a viable point design and highlight the factors most significant in the structural sizing.

Thermoplastic composites↗

Structural Sizing of a 50-m-Tall Thermoplastic Composite Truss Tower Structure for the Lunar South Pole

At the lunar south pole, solar arrays elevated by truss towers are exposed to near continuous sunlight since the sun remains near the horizon. Recent studies suggest that tower heights on the order of 50 m are needed to meet the power requirements to support a sustained lunar presence. While eventually towers may be constructed using materials sourced in-situ, initially structural elements will likely be brought from the Earth, deployed, and assembled. Thermoplastic composites offer the benefit of high specific stiffness and strength properties along with welding for assembly joints, and therefore represent a promising material system for this application. The focus of this paper is on the structural sizing of such towers. A set of expressions based on beam theory are presented for preliminary sizing of the truss tower structure for strength and buckling. The loading condition that drives sizing is base excitation resulting from moonquakes. A point design, developed through finite element analysis, verifies the analytical sizing routine and shows the importance of joints. The results show a viable point design and highlight the factors most significant in the structural sizing.

Thermoplastic composites↗

Self-consistent modeling of tokamak edge plasma transport with lithium sources

Magnetic confinement fusion devices require effective heat and particle exhaust solutions on the divertor plates to operate sustainably, especially under reactor-relevant conditions. Liquid lithium divertors have been proposed to address two major challenges: control of excessive heat flux to plasma-facing components through vapor shielding and minimization of core plasma contamination from impurities. The National Spherical Torus Experiment-Upgrade (NSTX-U) will explore lithium as a divertor material due to its potential to meet both objectives. We present a self-consistent coupling framework between the plasma boundary transport code UEDGE and the lithium wall transport code Wall–Li to evaluate the feasibility and operational limits of lithium-based divertors. The model aims to optimize lithium sourcing levels to prevent core plasma contamination via fuel dilution while ensuring divertor protection through vapor shielding. This integrated framework, applicable to any tokamak with lithium sources, dynamically adjusts lithium sourcing based on local plasma conditions and surface temperature. The coupled model is tested using NSTX-like geometry and plasma conditions to assess its performance and reliability. Wall–Li calculates lithium fluxes from plasma-facing components, incorporating physical sputtering, thermally enhanced sputtering, and evaporation driven by surface temperature and ion flux. These fluxes are reintroduced into UEDGE as neutral lithium atoms, enabling simulation of their transport and distribution within the plasma. UEDGE computes plasma and neutral transport, surface heat flux, and iteratively feeds this information back to Wall–Li. A small time step is employed to ensure numerical stability and convergence, enabling accurate simulations over typical tokamak discharge durations. This integrated modeling approach provides a robust tool for identifying operational regimes that balance effective lithium sourcing with minimal core plasma contamination, offering critical insights for optimizing lithium-based divertor systems in current and future fusion devices.

Magnetic confinement fusion↗

Multicriteria Measures to Assess the Sustainability of Diets: A Systematic Review

Abstract Context Assessing the overall sustainability of a diet is a challenging undertaking requiring a holistic approach capable of addressing the multicriteria nature of this concept. Objective The aim was to identify and summarize the multicriteria measures used to assess the sustainability characteristics of diets reported at the individual level by healthy adults. Data Sources Articles were identified via PubMed, Scopus, and Web of Science. The search strategy consisted of key words and MeSH terms, and was concluded in September 2022, covering references in English, Spanish, and Portuguese. Data Extraction This systematic review followed the PRISMA guidelines. The search identified 5663 references, from which 1794 were duplicates. Two reviewers independently screened the titles and abstracts of each of the 3869 records and the full-text of the 144 references selected. Of these, 7 studies met the inclusion criteria. Data Analysis A total of 6 multicriteria measures were identified: 3 different Sustainable Diet Indices, the Quality Environmental Costs of Diet, the Quality Financial Costs of Diet, and the Environmental Impact of Diet. All of these incorporated a health/nutrition dimension, while the environmental and economic dimensions were the second and the third most integrated, respectively. A sociocultural sustainability dimension was included in only 1 of the measures. Conclusion Despite some methodological concerns in the development and validation process of the identified measures, their inclusion is considered indispensable in assessing the transition towards sustainable diets in future studies. Systematic Review Registration PROSPERO registration no. CRD42022358824.

Rei, Mariana (ORCID:0000000189453708)↗

Near-Term Electricity Requirement and Emission Implications for Sustainable Aviation Fuel Production with CO 2 -to-Fuels Technologies

Aviation contributed approximately 10% of the U.S. transportation sector's greenhouse gas (GHG) emissions and about 3% of the nation's total GHG production before the coronavirus disease (COVID-19) pandemic (EPA 2022). Unlike the ground transportation sector, which can be decarbonized by using batteries and hydrogen fuel cell powertrain technologies, the technical and economic challenges of aviation electrification open the opportunity for CO 2 utilization (CO2U) using clean power sources. The U.S. government set a goal to produce 3 billion gallons per year of sustainable aviation fuels (SAF) by 2030 and scale up the production to 35 billion gallons per year by 2050 (Bioenergy Technologies Office 2022). In this report, we examine three potential locations, in California, Iowa, and Louisiana, for SAF production using two production pathways that are expected to be available by 2030. We analyze the electricity cost to satisfy 10% of the SAF production potential for the select locations. Specifically, we consider (1) retail electricity cost from the default local utility in each location; (2) physical power purchase agreement (PPA) for renewable power and battery storage hybrid systems with preset prices; (3) financial PPA from a dedicated renewable plant; and (4) estimated real-time pricing (RTP) from the wholesale power market with utility delivery adders. Retail rates are available for the three potential locations; however, the developer should negotiate with the local utility in Iowa for new tariff riders, because the load of the proposed SAF plant (1.4 GW) is significantly higher than the current industrial tariff structure requirement (200 kW). The developers are not able to claim federal credits (i.e., the Inflation Reduction Act of 2022) when sourcing electricity from local utilities. Developers could consider prioritizing physical and financial PPAs as purchase options. While physical PPAs can be imported out of state, this structure imposes availability issues as developers must locate in the same electricity grid regions. Financial PPAs do not have the same location restrictions and provide the same cost savings as physical PPAs, but financial PPAs impose financial risks in the event of system curtailment and grid interruption. RTPs are available for customers in California with flexible load and hourly load management capability; however, utilities in our studied regions in Louisiana and Iowa only offer time-of-use and curtailment programs to incentivize lower energy usage in peak hours. These utilities do not currently offer RTP programs, and the developer may need to have further negotiations with the local utilities to access RTP programs. The results show that purchased electricity prices may range from 2.6 cents/kWh to 7.1 cents/kWh for the three studied plants.

02 PETROLEUM↗

Sustainable chemistry with plasmonic photocatalysts

There is a pressing global need to increase the use of renewable energy sources and limit greenhouse gas emissions. Towards this goal, highly efficient and molecularly selective chemical processes that operate under mild conditions are critical. Plasmonic photocatalysis uses optically resonant metallic nanoparticles and their resulting plasmonic, electronic, and phononic light-matter interactions to drive chemical reactions. The promise of simultaneous high-efficiency and product-selective reactions with plasmon photocatalysis provides a compelling opportunity to rethink how chemistry is achieved. Plasmonic nanoparticles serve as nanoscale ‘antennas’ that enable strong light–matter interactions, surpassing the light-harvesting capabilities one would expect purely from their size. Complex composite structures, combining engineered light harvesters with more chemically active components, are a focal point of current research endeavors. In this review, we provide an overview of recent advances in plasmonic catalysis. We start with a discussion of the relevant mechanisms in photochemical transformations and explain hot-carrier generation and distributions from several ubiquitous plasmonic antennae. Then we highlight three important types of catalytic processes for sustainable chemistry: ammonia synthesis, hydrogen production and CO 2 reduction. To help elucidate the reaction mechanism, both state-of-art electromagnetic calculations and quantum mechanistic calculations are discussed. This review provides insights to better understand the mechanism of plasmonic photocatalysis with a variety of metallic and composite nanostructures toward designing and controlling improved platforms for green chemistry in the future.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Assessing Eruption Column Height in Ancient Flood Basalt Eruptions

A buoyant plume model is used to explore the ability of flood basalt eruptions to inject climate-relevant gases into the stratosphere. An example from the 1986 Izu-Oshima basaltic fissure eruption validates the model's ability to reproduce the observed maximum plume heights of 12-16 km above sea level, sustained above fire-fountains. The model predicts maximum plume heights of 13-17 km for source widths of between 4-16 m when 32% (by mass) of the erupted magma is fragmented and involved in the buoyant plume (effective volatile content of 6 wt%). Assuming that the Miocene-age Roza eruption (part of the Columbia River Basalt Group) sustained fire-fountains of similar height to Izu-Oshima (1.6 km above the vent), we show that the Roza eruption could have sustained buoyant ash and gas plumes that extended into the stratosphere at approximately 45 deg N. Assuming 5 km long active fissure segments and 9000 Mt of SO2 released during explosive phases over a 10-15 year duration, the approximately 180 km of known Roza fissure length could have supported approximately 36 explosive events/phases, each with a duration of 3-4 days. Each 5 km fissure segment could have emitted 62 Mt of SO2 per day into the stratosphere while actively fountaining, the equivalent of about three 1991 Mount Pinatubo eruptions per day. Each fissure segment could have had one to several vents, which subsequently produced lava without significant fountaining for a longer period within the decades-long eruption. Sensitivity of plume rise height to ancient atmospheric conditions is explored. Although eruptions in the Deccan Traps (approximately 66 Ma) may have generated buoyant plumes that rose to altitudes in excess of 18 km, they may not have reached the stratosphere because the tropopause was substantially higher in the late Cretaceous. Our results indicate that some flood basalt eruptions, such as Roza, were capable of repeatedly injecting large masses of SO2 into the stratosphere. Thus sustained flood basalt eruptions could have influenced climate on time scales of decades to centuries but the location (i.e., latitude) of the province and relevant paleoclimate is important and must be considered.

climate↗

Visual Systems Mapping to Define and Compare Woody Biomass LCAs for Sustainable Systems

The challenge addressed in this research centres on the need to choose between several biomass sources and energy production processes, while supporting rural economies and resilience of forest systems. A key barrier to effective decision-making for strategies using biomass is the lack of standardized and transparent life cycle assessment (LCA) baselines. These baselines are critical for assessing the impacts of biomass strategies but often vary due to regional factors and chosen simplifying assumptions of the LCAs. However, omitting key variables can mean the LCA omits key feedback and balancing loops relevant to fully assessing impacts of the change or test scenario. To address these complexities, this project employs a systems engineering approach: visual systems mapping. This technique is used to define the boundaries and dynamic behaviours of LCA baselines, enhancing transparency. By examining five literature sources and their documented baseline scenarios, the systems mapping case-studies demonstrates an approach to documenting and archiving these baselines. Recommendations are that visual systems mapping should be used to document key assumptions, such as baselines, of LCAs. Further, where possible open data repositories should hold key information about LCA baselines and reproducible workflows (e.g., using open-source tools) should be used to improve transparency and comparability in LCAs. Given the consensus within the broader scientific community on the importance of replicable data practices, this research reinforces the need for standardized frameworks and systems engineering tools in LCAs. This research demonstrates a pathway to more transparent, standardized, and comparable LCAs, that may bolster decisions for biomass systems.

Davis, Maggie [ORNL] (ORCID:0000000181319328)↗