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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 1,621 records · Page 90
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Integrating CO2 Electrolysis with Gas Fermentation to Produce Valuable Fuels and Chemicals

Many industrial activities squander CO2, decreasing process yield. We envision a future where this waste carbon is instead captured, upgraded, and valorized directly at the point of emission. Within the CO2 Reduction and Upgrading Consortium (a collaboration of seven US national laboratories and industrial partners), we are pursuing this goal by developing and de-risking new technologies for low temperature CO2 electrolysis, coupled with biological upgrading of intermediates into more valuable compounds. One such process involves electrocatalytic reduction of CO2 to generate carbon monoxide (CO). As both a carbon and energy source, CO represents an attractive feedstock for microbial upgrading by certain syngas-fermenting species, such as the autotrophic bacterium Clostridium autoethanogenum. Our team has developed new genetic tools and optimized cultivation techniques to enhance C. autoethanogenum as a platform host for the biological conversion of syngas into value-added products. For example, we have created novel CRISPR-based genetic engineering techniques to build new, genome-reduced, platform strains of C. autoethanogenum with improved growth rates. Further, we ve introduced heterologous biochemical pathways into C. autoethanogenum to enable the production of high-value compounds from syngas, such as the isoprenoid precursor mevalonic acid. With the tools of electrochemistry and synthetic biology, there is virtually no limit to the spectrum of products that could be sustainably manufactured from CO2.

09 BIOMASS FUELS↗
DOE OSTI2025

Local Cation-Ordered Superlattice Stabilizing Ni-Rich Single-Crystalline Cathodes

Ni-rich single-crystalline cathodes are pivotal for advancing lithium-ion battery technology due to their high energy density and mechanical stability. However, Ni-rich single-crystalline particles face intrinsic structural heterogeneity due to excessively high sintering temperature required to shape micron-sized morphologies─typically over 150 °C above the polycrystalline optimum, leading to rapid electrochemical decay and unsatisfied rate performance that hinder their practical application. Here, in this work, we propose a lithium-deficient presintering strategy to synthesize cation-ordered single-crystalline LiNi 0.83 Co 0.12 Mn 0.05 O 2 (S-NCM83), effectively minimizing lattice chemical heterogeneity and defect formation. The resulting cation-ordered percolation network enhances the structural stability of the bulk, reduces the energy barrier for Li + migration, and stabilizes Li + diffusion pathways. Consequently, S-NCM83 demonstrates significantly improved cycling stability across various operating temperatures and achieves exceptional rate performance, delivering 206 mAh g –1 at 0.1 C and 170 mAh g –1 at 5 C, without requiring surface coatings or doping. This work introduces a universal strategy to address the long-standing structural instability issues in single-crystalline cathodes, paving the way for simplified and scalable approaches to long-life and high-energy lithium-ion batteries.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Remediation and upcycling of microplastics by algae with wastewater nutrient removal and bioproduction potential

Microplastics have emerged as major environmental hazards that require efficient, cost-effective, and sustainable remediation technologies. This study introduces an integrative platform for the remediation and upcycling of microplastics by algae, while synergizing with plastic upcycling, wastewater treatment, and algal production. The strategy employs a mechanism that enhances hydrophobic interactions between the cell surface and microplastics, enabling rapid aggregation and removal. The platform achieves a superior microplastic removal efficiency of 91.4% within 1 hour, with a capacity of 0.1-gram microplastic per gram of biomass. Furthermore, the study demonstrates an upcycling strategy that converts microplastics-enriched cyanobacteria into plastic composites with unique performance. This work also integrates microplastic removal with cyanobacterial bioproduction and wastewater treatment, offering an approach that synergizes remediation with these value-added processes. Ultimately, this platform provides a viable and sustainable pathway to address microplastic pollution by creating value through plastic upcycling, wastewater nutrient removal, and CO 2 -based bioproduction.

09 BIOMASS FUELS↗
NASA NTRS2017

Risk of Adverse Health Outcomes and Decrements in Performance Due to In-flight Medical Conditions

The drive to undertake long-duration space exploration missions at greater distances from Earth gives rise to many challenges concerning human performance under extreme conditions. At NASA, the Human Research Program (HRP) has been established to investigate the specific risks to astronaut health and performance presented by space exploration, in addition to developing necessary countermeasures and technology to reduce risk and facilitate safer, more productive missions in space (NASA Human Research Program 2009). The HRP is divided into five subsections, covering behavioral health, space radiation, habitability, and other areas of interest. Within this structure is the ExMC Element, whose research contributes to the overall development of new technologies to overcome the challenges of expanding human exploration and habitation of space. The risk statement provided by the HRP to the ExMC Element states: "Given that medical conditions/events will occur during human spaceflight missions, there is a possibility of adverse health outcomes and decrements in performance in mission and for long term health" (NASA Human Research Program 2016). Within this risk context, the Exploration Medical Capabilities (ExMC) Element is specifically concerned with establishing evidenced-based methods of monitoring and maintaining astronaut health. Essential to completing this task is the advancement in techniques that identify, prevent, and treat any health threats that may occur during space missions. The ultimate goal of the ExMC Element is to develop and demonstrate a pathway for medical system integration into vehicle and mission design to mitigate the risk of medical issues. Integral to this effort is inclusion of an evidence-based medical and data handling system appropriate for long-duration, exploration-class missions. This requires a clear Concept of Operations, quantitative risk metrics or other tools to address changing risk throughout a mission, and system scoping and system engineering. Because of the novel nature of the risks involved in exploration missions, new and complex ethical challenges are likely to be encountered. This document describes the relevant background and evidence that informs the development of an exploration medical system.

Antonsen,Erik↗
DOE OSTI2023

Reactor Network Analysis with Various Reaction Mechanisms to Investigate Hydrogen vs. Methane Fuel at Varying Flame Temperatures with Experimental Data

Emissions data were evaluated for a set of test hardware that adapts Collins Aerospace’s aeroengine liquid fueled injector technology to a ground-based turbine. The hardware was specifically developed to operate on 100% hydrogen; however it has the ability to operate on both pure methane and hydrogen and mixtures in between. 16 injector configurations and seven factors (air split, fuel and air swirl, pressure drop, preheat temperature, fuel composition, and flame temperature) were investigated based on a Box Behnken statistical model. Of the 16, configuration 3 was selected for further discussion being in the middle of the statistical design space. A chemical reactor network was developed based on the experimental data obtained and was assessed with three different mechanisms: GRI Mech 3.0, UCSD, and Galway. All factors were held constant except the fuel composition to directly compare chemical pathways for methane and hydrogen. This study was conducted across different flame temperatures of 1500K, 1675K, and 1850K for both hydrogen and methane. Additional lower flame temperatures of 1100K and 1300K were evaluated for hydrogen. Moreover, results for fully premixed and non-premixed results were compared to obtain information on the implications of mixedness on emissions. These results were compared with the Leonard and Stegmaier plot for methane and a similar plot was constructed for hydrogen.

08 HYDROGEN↗
DOE OSTI2025

Single-Molecule Conductance through Hybrid Radially and Linearly π-Conjugated Macromolecules Reveals an Unusual Intramolecular π-Interaction

We describe the design, synthesis, and single-molecule junction conductance of π-electron molecules bearing both radial and linear π-conjugation pathways, whereby cycloparaphenylene (CPP) radial cores are π-extended linearly with aryl alkyne substituents as models for previously reported CPP-arylene ethynylene conjugated polymers. Although radially and linearly conjugated molecules have been studied previously in isolation as junction-bridging molecular electronic units, this is the first study to examine molecules where both topologies are operative. Our results reveal that the presence of radial CPP components within the junction-spanning pathway leads to a reduction in the conductance of the backbone compared to model linear phenyl substituents. Through tight-binding and DFT-based calculations, we attribute this conductance change to intramolecular van der Waals (vdW) interactions between the CPP ring and the junction-spanning arylene-ethynylene molecular backbone. These interactions induce changes in the dihedral angles of the backbone, leading to a reduced overlap of π orbitals within the molecular junction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Multiscale modeling and laser diagnostics to reveal non-equilibrium reaction chemistry at a plasma-liquid interface

Low-temperature, atmospheric-pressure plasmas in contact with liquid are at the core of a wide range of applications including water treatment, medicine, materials synthesis, and chemical transformation. In general, plasma-liquid processes are scientifically compelling because reactivity can be produced without a catalyst, in relatively inert molecules, such as air or nitrogen and liquid water, in their native states at ambient conditions. However, reactions at a plasma-liquid interface are extremely complex, occurring at a multiphase, gas-liquid boundary where excited or dissociate gaseous species dissolve and react with solution-phase species, and unique reaction pathways are induced by non-equilibrium chemistry. In particular, detailed knowledge of the physical and chemical processes, including what species are produced in the gas phase and how these species are subsequently transported across and react near the interfacial region, remains largely unanswered. In this project, modeling of the non-equilibrium reaction chemistry at the interface of low-temperature, atmospheric-pressure plasmas and liquid water is developed, supported by advanced laser diagnostics.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

Charging, aggregation, and electrostatic dispersion of radioactive and nonradioactive particles in the atmosphere

Electrostatic dispersion can significantly impact the microphysical behavior of charged particles and ions until reaching zero space charge. However, although radioactive particles can be strongly charged in air, the influence of electrostatic dispersion has been neglected in understanding their behavior. This study is aimed at investigating the time evolution of the charge and size distributions of radioactive and nonradioactive particles in air and developing simple approaches for applications. With processes involving charging, aggregation, and electrostatic dispersion, a comprehensive population balance model (PBM) has been developed to examine particle charge/size distribution dynamics. It is shown that compared to nonradioactive particles, the charge and size distributions of radioactive particles may evolve differently with time because radioactivity and electrostatic dispersion can significantly affect the charging and aggregation kinetics of the particles. It is found that, after the Fukushima accident, background aerosols in the pathway of radioactive plumes might be highly charged due to ionizing radiation, suggesting that radiation fields may strongly influence in situ measurements of charged atmospheric particles. The comprehensive PBM is simplified, and then the verification and application of the simplified PBMs are discussed. This study provides useful insight into how radioactivity can affect the dynamic behavior of particles in atmospheric systems including radiation sources.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Artificial extracellular matrix scaffolds of mobile molecules enhance maturation of human stem cell-derived neurons

Human induced pluripotent stem cell (hiPSC) technologies offer a unique resource for modeling neurological diseases. However, iPSC models are fraught with technical limitations including abnormal aggregation and inefficient maturation of differentiated neurons. These problems are in part due to the absence of synergistic cues of the native extracellular matrix (ECM). We report on the use of three artificial ECMs based on peptide amphiphile (PA) supramolecular nanofibers. All nanofibers display the laminin-derived IKVAV signal on their surface but differ in the nature of their non-bioactive domains. Here, we find that nanofibers with greater intensity of internal supramolecular motion have enhanced bioactivity toward hiPSC-derived motor and cortical neurons. Proteomic, biochemical, and functional assays reveal that highly mobile PA scaffolds caused enhanced β1-integrin pathway activation, reduced aggregation, increased arborization, and matured electrophysiological activity of neurons. Our work highlights the importance of designing biomimetic ECMs to study the development, function, and dysfunction of human neurons.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2025

Photoionization of seeded combustion products as a method of enhancing the efficiency of magnetohydrodynamic power generators

Here, in this study, we performed an experimental and computational investigation into the feasibility of utilizing photoionization to enhance the electrical conductivity of seeded oxy-fuel combustion products and improve the performance of magnetohydrodynamic (MHD) power generators. We applied a variety of optical and microwave diagnostics to study the ionization and recombination processes of potassium excited by an excimer laser in a high-velocity oxy-fuel free jet. Computational fluid dynamic (CFD) simulations were performed to model the thermophysical properties and species densities of the free jet. The CFD results were validated with position-dependent potassium concentration measurements. Electron recombination exponential lifetimes were measured through time-resolved microwave transmission. The experimental electron lifetimes were compared with lifetimes calculated from CFD-predicted species densities and literature recombination rates. It was determined that K + or O 2 are the most likely recombination partners for photoionized electrons. Time-resolved fluorescence measurements provided evidence of an ionization pathway involving a two-photon ionization of KOH . Finally, a zero-dimensional chemical kinetic model was developed to assess the fundamental viability of inducing a non-equilibrium electron population to provide a net energy return in combustion-driven MHD power generators. We determined that a high energy return is feasible for targeting electrode boundary layers with ultraviolet photoionization. We also found that photoionization could potentially lower the required temperature of the bulk gas flow.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2023

Array-Based Machine Learning for Functional Group Detection in Electron Ionization Mass Spectrometry

Mass spectrometry is a ubiquitous technique capable of complex chemical analysis. The fragmentation patterns that appear in mass spectrometry are an excellent target for artificial intelligence methods to automate and expedite the analysis of data to identify targets such as functional groups. To develop this approach, we trained models on electron ionization (a reproducible hard fragmentation technique) mass spectra so that not only the final model accuracies but also the reasoning behind model assignments could be evaluated. The convolutional neural network (CNN) models were trained on 2D images of the spectra using transfer learning of Inception V3, and the logistic regression models were trained using array-based data and Scikit Learn implementation in Python. Our training dataset consisted of 21,166 mass spectra from the United States’ National Institute of Standards and Technology (NIST) Webbook. The data was used to train models to identify functional groups, both specific (e.g., amines, esters) and generalized classifications (aromatics, oxygen-containing functional groups, and nitrogen-containing functional groups). We found that the highest final accuracies on identifying new data were observed using logistic regression rather than transfer learning on CNN models. It was also determined that the mass range most beneficial for functional group analysis is 0–100 m/z. We also found success in correctly identifying functional groups of example molecules selected from both the NIST database and experimental data. Beyond functional group analysis, we also have developed a methodology to identify impactful fragments for the accurate detection of the models’ targets. The results demonstrate a potential pathway for analyzing and screening substantial amounts of mass spectral data.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

The zero-emissions cost of energy: a policy concept

The energy sector generates over 70% of global greenhouse gas (GHG) emissions, but existing energy-climate policies do little to reduce GHG emissions to prevent climate change. We present a new carbon tax policy concept in which energy users would be taxed an amount equal to the cost of cleaning up the emissions that they create, wherein the tax revenues would be used to operate negative emissions technologies. The policy is based on applying the zero-emissions cost (ZEC) metric to energy prices, which includes the 'regular' cost of an energy source plus the cost of sequestering its emissions. Using the ZEC, (a) the energy sector would be emissions-neutral, (b) biofuels would be cheaper than petroleum fuels, and (c) renewable electricity would be cheaper than fossil-fuel electricity. We calculate the energy spending as a fraction of gross domestic product for 'regular' and ZEC cost scenarios. Implementing the ZEC carbon-tax policy would enable a monumental shift to a net-zero emissions energy sector, but carries a significant risk of causing an economic recession. The summary point of this commentary is to demonstrate a pathway to achieve net-zero GHG emissions from the US energy sector, and to contemplate the associated economic impacts on our society.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2022

U.S. Department of Energy’s Industrial Decarbonization Roadmap

The science is clear that significant greenhouse gas (GHG) emissions reductions are needed to moderate the severe impacts of ongoing climate change. Bold action is needed, and the Biden Administration has set goals of 100% carbon pollution-free electricity by 2035 and net-zero GHG emissions by 2050. The U.S. Long-Term Strategy (LTS) presents multiple pathways to a net-zero economy by no later than 2050. Addressing environmental justice and energy equity will be integral to meeting these climate goals. The United States’ overall industrial decarbonization strategy will support the Biden Administration’s Justice40 Initiative, which pledges that at least 40% of overall benefits from federal investments in climate and clean energy will be delivered to disadvantaged communities. The U.S. net-zero GHG 2050 goal, while ambitious, is achievable and will provide important benefits for all Americans in terms of public health, economic growth, reduced conflict from climate-related disasters, and quality of life. While this roadmap focuses on GHG emissions, other pollutant emissions will also need to be addressed as industry decarbonizes. Developing new technologies to reduce GHG emissions is an important opportunity to address other environmental issues and inequities. DOE is currently focusing on energy and environmental justice in complementary programs and initiatives. The U.S. industrial sector is considered a “difficult-to-decarbonize” sector of the energy economy, in part because of the diversity of energy inputs that feed into a heterogenous array of industrial processes and operations. In 2020, the industrial sector accounted for 33% of the nation’s primary energy use and 30% of energy-related carbon dioxide (CO 2 ) emissions.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Development of Metal-Free Photocatalysts

Solar fuels show great promise as clean, sustainable energy sources; however, established technologies are still plagued by high price, toxicity concerns, or low efficiencies. There is a critical need for inexpensive, benign materials that can effectively harness the sun’s energy. The overarching objective of this project is to evaluate the compatibility of novel material combinations for use as metal-free, heterojunction photocatalysts. Our central hypothesis is that by tuning the electronic structure of individual components in hybrid composites, via selective chemical modifications and physical stimuli to the interface, we can improve the photocatalytic properties of the overall assembly. We will determine factors that affect energy band gaps and band edge positions in isolated photocatalyst systems as well as explore routes to modulate heterojunction band alignments in composite assemblies. Our results will predict accessible pathways for charge carriers in new composite photocatalysts, facilitating access to more of the solar spectrum via inexpensive, environmentally-friendly material combinations.

14 SOLAR ENERGY↗
DOE OSTI2025

Efficient Hamiltonian encoding algorithms for extracting quantum control mechanism as interfering pathway amplitudes in the Dyson series

Hamiltonian encoding is a methodology for revealing the mechanism behind the dynamics governing controlled quantum systems. In this paper, following Mitra and Rabitz \cite{abhra_1}, we define mechanism via pathways of eigenstates that describe the evolution of the system, where each pathway is associated with a complex-valued amplitude corresponding to a term in the Dyson series. The evolution of the system is determined by the constructive and destructive interference of these pathway amplitudes. Pathways with similar attributes can be grouped together into pathway classes. The amplitudes of pathway classes are computed by modulating the Hamiltonian matrix elements and decoding the subsequent evolution of the system rather than by direct computation of the individual terms in the Dyson series. The original implementation of Hamiltonian encoding was computationally intensive and became prohibitively expensive in large quantum systems. This paper presents two new encoding algorithms that calculate the amplitudes of pathway classes by using techniques from graph theory and algebraic topology to exploit patterns in the set of allowed transitions, greatly reducing the number of matrix elements that need to be modulated. These new algorithms provide an exponential decrease in both computation time and memory utilization with respect to the Hilbert space dimension of the system. To demonstrate the use of these techniques, they are applied to two illustrative state-to-state transition problems.

Abrams, Erez [Princeton University, Massachusetts ↗
DOE OSTI2020

Critical material content in modern conventional U.S. vehicle electronics

Critical materials (CM) are vital to modern technology. Components of modern vehicles can be recycled to recover and reuse the CMs to help ensure a supply of these materials. Electronic components from a 2015 GMC Sierra truck (21 components) and 2016 Toyota Camry sedan (10 components) were analyzed for CMs. The components were processed via size reduction, aqua regia leaching and dissolution, and final solutions were analyzed for metal content. It was found that most electronic components of both vehicles contain CM. The most concentrated CM in the components were Sn, Nb, and Tb. Nd and Co were found in several of the magnetic components. CM economic value was found to be low compared to the overall value of the components, and the CM content would not allow for a viable pathway for recycling. Remanufacturing of components may be a more economic option of reuse in the future.

2015 GMC Sierra↗
DOE OSTI2024

Protective Catalyst Systems on III-V and Si-based Semiconductors for Efficient, Durable Photoelectrochemical Water Splitting Devices

The overall goal of this project was to develop unassisted water splitting devices based on III-V materials, creating pathways to improve performance in terms of efficiency, improve durability, and cost. One major objective is to develop pathways to systems that can ultimately achieve > 20% solar-to-hydrogen (STH) efficiency. Another objective was to develop pathways to high efficiency systems that can operate on-sun for at least 2 weeks. With respect to cost, this research provide new approaches to tandem photoelectrode design and fabrication that one day may allow for costs to reach $200/m 2 . Two distinct water splitting schemes were explored: Scheme 1 aims to develop high efficiency devices with tandem III-V photoabsorbers (e.g. GaInP 2 /GaInAs) with Scheme 2 targeting cost reduction while maintaining high efficiency by growing InGaN on crystalline Si (InGaN/Si). Both schemes were employed to couple with thin film, semi-transparent, catalytic/protection layers containing reduced or zero precious metal content that can enhance durability while maintaining high efficiency and enabling low material costs. Overall the project greatly advanced the technology to developing high performance systems with increased durability, as demonstrated by true on-sun testing through partnership with the National Renewable Energy Laboratory (NREL).

08 HYDROGEN↗