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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Lignin structural changes and high p -coumaroylation in incipient lignification in moso bamboo

Lignification is a crucial process for strengthening plant tissues, facilitating water transport, and providing defense against pathogens. In the Poaceae family, p-hydroxycinnamic acids are commonly incorporated into lignin, with acylation by p-coumarate (pCA) occurring during lignification. In this study, we performed DFRC and 2D HSQC-NMR analyses to investigate changes in lignin substructures and the degree of lignin pCA-acylation throughout bamboo stem development. Furthermore, immunohistochemical analysis was conducted to elucidate the spatial distribution of lignin substructures within different cell types. Our results revealed that, in young tissues, β–O–4-linked lignin units are predominantly derived from monolignol-pCA conjugates, specifically coniferyl- and sinapyl-pCA. Both lignin structure and the pattern of pCA acylation varied depending on the stage of cell wall formation and the cell type, particularly between vascular fiber cells and parenchyma cells. Based on our results, moso bamboo culms exhibit a distinctive feature during incipient lignification, in which monolignols are predominantly acylated with pCA. As a result, this feature has not been reported in other grasses, suggesting that extensive p-coumaroylation of monolignols plays an important role in the rapid elongation of bamboo culms.

Munekata, Noriaki [Kyoto University (Japan); Unive↗
DOE OSTI2022

Toward wide-spectrum antivirals against coronaviruses: Molecular characterization of SARS-CoV-2 NSP13 helicase inhibitors

To date, effective therapeutic treatments that confer strong attenuation against coronaviruses (CoVs) remain elusive. Among potential drug targets, the helicase of CoVs is attractive due to its sequence conservation and indispensability. We rely on atomistic molecular dynamics simulations to explore the structural coordination and dynamics associated with the SARS-CoV-2 Nsp13 apo enzyme, as well as their complexes with natural ligands. A complex communication network is revealed among the five domains of Nsp13, which is differentially activated because of the presence of the ligands, as shown by shear strain analysis, principal components analysis, dynamical cross-correlation matrix analysis, and water transport analysis. The binding free energy and the corresponding mechanism of action are presented for three small molecules that were shown to be efficient inhibitors of the previous SARS-CoV Nsp13 enzyme. Together, our findings provide critical fresh insights for rational design of broad-spectrum antivirals against CoVs.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

High-pressure behavior of 3.65 Å phase: Insights from Raman spectroscopy

Abstract The 3.65 Å phase [MgSi(OH)6] is a hydrous phase that is predicted to be stable in a simplified MgO-SiO2-H2O (MSH) ternary system at pressures exceeding 9 GPa. Along cold subduction zones, it is likely to transport water, bound in its crystalline lattice, into the Earth’s interior. The 3.65 Å phase consists of Mg and Si octahedral sites attached to the hydroxyl group that forms a hydrogen bond and is predicted to undergo pressure-induced symmetrization of the hydrogen bond. Therefore, in this study, we investigate the high-pressure behavior of the 3.65 Å phase using Raman spectroscopy. We have conducted five distinct compressions up to ~60 GPa using two different pressure-transmitting media—alcohol mixture and neon. At ambient conditions, we identified vibrational modes using complementary first-principles simulations based on density functional perturbation theory. Upon compression, we note that the first derivative of the vibrational modes in the lattice region stiffens, i.e., b1lattice > 0. In contrast, the hydroxyl region softens, i.e., b1OH > 0. This is indicative of the strengthening of hydrogen bonding upon compression. We noticed a significant broadening of vibrational modes related to hydroxyl groups that are indicative of proton disorder. However, within the maximum pressures explored in this study, we did not find evidence for pressure-induced symmetrization of the hydrogen bonds. We used the pressure derivative of the vibrational modes to determine the ratio of the bulk moduli and their pressure derivative. We note that the smaller bulk moduli of hydrous phases compared to the major mantle phases are compensated by significantly larger pressure derivatives of the bulk moduli for the hydrous phases. This leads to a significant reduction in the elasticity contrast between hydrous and major mantle phases. Consequently, the detection of the degree of mantle hydration is likely to be challenging at greater depths.

Geochemistry & Geophysics↗
DOE OSTI2020

Chimeric Protein Treatment of Pierce Disease

Pierce disease is an economically costly disease for several agricultural crops, including grapes, citrus, and olives. An invasive insect species, the glassy-winged sharpshooter, harbors a gut bacteria that kills grape vines. The bacteria destroys the xylem, the water transport tissue in plants. Los Alamos researchers have designed a technology to target and kill the source of Pierce disease. The treatment does not require the use of pesticides or the removal and replacement of the effected vines.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Control of Carbon Allocation in Phenylpropanoid Metabolism

Understanding the molecular mechanisms by which carbon flux is partitioned in plants, and how flux through the phenylpropanoid pathway in particular is regulated and allocated to different branches of the pathway is essential for the eventual rational manipulation of phenylpropanoid flux for bioenergy applications. The phenylpropanoid pathway is responsible for the biosynthesis of a diverse array of metabolites essential for structural integrity, water transport, UV protection, and defense against herbivores and pathogens. The products of the phenylpropanoid pathway, all of which are derived from phenylalanine, range from complex, insoluble polymers such as lignin and suberin, to soluble flavonoids and hydroxycinnamate esters, to volatile compounds used to attract pollinators. By far the most abundant of these is the complex heteropolymer lignin, which accounts for a significant portion of the dry weight of not only woody plants, but also of crop residues. Decreasing or altering lignin structure to provide increased cell wall digestibility could greatly increase the cost effectiveness of converting cell wall polysaccharides to ethanol or second-generation biofuels. On the other hand, it is also possible that plants engineered to accumulate higher levels of lignin could provide improved feedstock for direct combustion and electricity generation as part of a diverse bioenergy portfolio. Consistent with the enormous commitment of energy and carbon it requires, the synthesis of lignin is under tight regulatory control. In order to influence transcription, gene-specific activators and repressors must interact with basal transcription factors and the rest of the core transcriptional machinery. In eukaryotes, this interaction is bridged by the large, multi-subunit complex known as Mediator. Despite the clear importance of Mediator throughout the eukaryotes, the complex has only recently been studied in plants. We have shown that a pair of Mediator subunits, MED5a and MED5b are required for normal regulation of phenylpropanoid pathway product accumulation. Plants lacking these proteins show increased accumulation of phenylpropanoids in multiple tissues indicating that normally they directly or indirectly repress expression of phenylpropanoid pathway genes. Furthermore, we have recently shown that MED5 plays a role in dwarfing in some low lignin plants and feedback between and within metabolic pathways of secondary metabolism in Arabidopsis. Taken together with the established roles of Mediator in transcriptional regulation, and of MED5a and MED5b in the repression of phenylpropanoid metabolism, these observations suggest that MED5a and MED5b are key components of an active, transcriptional process by which phenylpropanoid homeostasis is maintained in wild-type plants. Our research focused on expanding our understanding of the role of Mediator, as well as elucidating the mechanisms by which these proteins influence phenylpropanoid biosynthesis and how metabolite accumulation within the pathway and between metabolic pathways is essential for feedback regulatory control. This research will inform future bioengineering efforts aimed at altering carbon allocation and cell wall engineering by contributing to our understanding of the role of Mediator in regulating lignin biosynthesis, a pathway of plant metabolism that is important on a global scale.

09 BIOMASS FUELS↗
DOE OSTI2026

Stakeholder-guided holistic, Adaptive Framework for enhancing community Energy Resilience (SAFER) (Final Technical Report)

The Stakeholder-guided holistic, Adaptive Framework for enhancing community Energy Resilience (SAFER) project advances resilience science and engineering by addressing challenges in rural Kansas communities where aging infrastructure, extreme weather, and socioeconomic disparities heighten vulnerability to energy disruptions. Traditional approaches often focus on technical performance while overlooking community concerns and priorities. SAFER responds by integrating community perspectives with advanced analytical frameworks to create a holistic model for measuring and improving resilience. Project objectives included developing novel resilience metrics, advancing modeling frameworks that capture interdependencies across infrastructures, and embedding community-centric indicators directly into planning processes for distributed energy resources. The key technical innovations included the creation of self-organizing map (SOM)-based indices for objective resilience quantification, hetero-functional graph theory (HFGT) models linking power, water, transportation, and community assets, and graph neural network (GNN) tools for identifying critical nodes in complex systems. Community-centric energy planning was demonstrated through optimal siting and sizing of (photovoltaic) PV and battery storage, ensuring resilience enhancements also addressed energy burden and energy insecurity. SAFER engaged community partners in Dodge City and Ford County through surveys, focus groups, and workshops, generating more than 600 responses that established baseline measures of energy burden, financial insecurity, and willingness-to-pay to avoid outages. This data, organized in terms of a community capitals framework, informed the development of weighted reliability indices that better reflect community costs than traditional utility metrics. SAFER’s GNN-based critical node identification framework identified expert-labelled critical nodes with over 99% accuracy, while also uncovering additional functionalities essential for proactive resilience planning. The project’s models demonstrated that optimal PV and storage deployment could improve resilience indices by over 11 percent, with dispatch strategies further enhancing outcomes, confirming both the technical effectiveness and economic feasibility of these approaches. Through its combined emphasis on rigorous modeling, community-focused planning, and community engagement, SAFER advances the state of resilience research while delivering direct benefits to rural communities. The project provides tools, guidelines, and resilience heatmaps that help utilities, local governments, and residents better anticipate disruptions, prioritize investments, and strengthen the capacity to withstand and recover from energy-related hazards. Furthermore, the developed HFG and GNN frameworks are designed for transferability, allowing them to be adapted for resilience planning in other communities with minimal retraining. This inductive learning capability provides a scalable pathway to extend the SAFER project’s impact. Thus, creating a foundation for a nationally applicable model of infrastructure resilience. Additionally, the HFG can also be extended to include other FEMA community lifelines.

14 SOLAR ENERGY↗
DOE OSTI2026

Hurricane Helene: Energy Systems Impact and Situational Insights in East Tennessee

This situational report focuses specifically on energy system performance and interdependencies associated with Hurricane Helene’s impacts across East Tennessee. It does not attempt to identify root causes, evaluate broader emergency response structures, or assess agency effectiveness. Rather, it aims to illuminate how energy disruptions intersected with other lifeline services, particularly water, transportation, and communications, and identify the infrastructural and logistical conditions that shaped those outcomes. Where possible, this report seeks to highlight both constraints and successful practices that emerged during the event.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2024

Visualization of lignification in flax stem cell walls with novel click-compatible monolignol analogs

As an essential part of plant cell walls, lignin provides mechanical support for plant growth, enhances water transport, and helps to defend against pathogens. As the most abundant natural aromatic-based renewable resource on earth, its biosynthesis has always been a research focus, and it is still currently under study. In this study, the p-coumaryl alcohol analog (H ALK ) and the coniferyl alcohol analog (G ALK ) containing an alkyne group at the ortho position were synthesized and applied to lignification in vivo and in vitro. The incorporation of these novel lignin monomers was observed via fluorescence imaging. It was found that the two monolignol analogs could be incorporated in dehydrogenated polymers (DHPs) in vitro and in flax cell walls in vivo. The results showed that as the cultivation time and precursor concentration varied, the deposition of H and G-type lignin exhibited differences in deposition mode. At the subcellular scale, the deposited lignin first appears in the cell corner and the middle lamella, and then gradually appears on the cell walls. Furthermore, lignin was also found in bast fiber. It was demonstrated that these new molecules could provide high-resolution localization of lignin during polymerization.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Direct Measurement of Crossover and Interfacial Resistance of Ion-Exchange Membranes in All-Vanadium Redox Flow Batteries

Among various components commonly used in redox flow batteries (RFBs), the separator plays a significant role, influencing resistance to current as well as capacity decay via unintended crossover. It is well-established that the ohmic overpotential is dominated by the membrane and interfacial resistance in most aqueous RFBs. The ultimate goal of engineering membranes is to improve the ionic conductivity while keeping crossover at a minimum. One of the major issues yet to be addressed is the contribution of interfacial phenomena in the influence of ionic and water transport through the membrane. In this work, we have utilized a novel experimental system capable of measuring the ionic crossover in real-time to quantify the permeability of ionic species. Specifically, we have focused on quantifying the contributions from the interfacial resistance to ionic crossover. The trade-off between the mass and ionic transport impedance caused by the interface of the membranes has been addressed. The MacMullin number has been quantified for a series of electrolyte configurations and a correlation between the ionic conductivity of the contacting electrolyte and the Nafion® membrane has been established. The performance of individual ion-exchange membranes along with a stack of various separators have been explored. We have found that utilizing a stack of membranes is significantly beneficial in reducing the electroactive species crossover in redox flow batteries compared to a single membrane of the same fold thickness. For example, we have demonstrated that the utilization of five layers of Nafion ® 211 membrane reduces the crossover by 37% while only increasing the area-specific resistance (ASR) by 15% compared to a single layer Nafion ® 115 membrane. Therefore, the influence of interfacial impedance in reducing the vanadium ion crossover is substantially higher compared to a corresponding increase in ASR, indicating that mass and ohmic interfacial resistances are dissimilar. We have expanded our analysis to a combination of commercially available ion-exchange membranes and provided a design chart for membrane selection based on the application of interest (short duration/high-performance vs. long-term durability). The results of this study provide a deeper insight into the optimization of all-vanadium redox flow batteries (VRFBs).

UV/Vis spectroscopy↗
DOE OSTI2021

Urban Energy Systems: Research at Oak Ridge National Laboratory

In the coming decades, our planet will witness unprecedented urban population growth in both established and emerging communities. The development and maintenance of urban infrastructures are highly energy-intensive. Urban areas are dictated by complex intersections among physical, engineered, and human dimensions that have significant implications for traffic congestion, emissions, and energy usage. In this chapter, we highlight recent research and development efforts at Oak Ridge National Laboratory (ORNL), the largest multipurpose science laboratory within the U.S. Department of Energy’s (DOE) national laboratory system, that characterizes the interactions between the human dynamics and critical infrastructures in conjunction with the integration of four distinct components: data, critical infrastructure models, and scalable computation and visualization, all within the context of physical and social systems. Discussions focus on four key topical themes: population and land use, sustainable mobility, the energy-water nexus, and urban resiliency, that are mutually aligned with DOE’s mission and ORNL’s signature science and technology capabilities. Using scalable computing, data visualization, and unique datasets from a variety of sources, the institute fosters innovative interdisciplinary research that integrates ORNL expertise in critical infrastructures including energy, water, transportation, and cyber, and their interactions with the human population.

Bhaduri, Budhu↗
DOE OSTI2021

Water and salt transport properties of pentiptycene-containing sulfonated polysulfones for desalination membrane applications

A series of pentiptycene-containing disulfonated polysulfone copolymers (PENT-BP) were synthesized via condensation polymerization. Water and salt transport properties (solubility, diffusivity and permeability) were characterized for acid-form membranes (PENT-BP(H)) and compared with triptycene-based sulfonated polysulfones (TRP-BP(H)) and a non-iptycene-containing 4,4'-biphenol-based series (BPS(H)) of polysulfones to investigate the effect of pentiptycene on membrane performance. At comparable water content, the PENT-BP(H) exhibited increased water and salt permeability due to the additional free volume introduced by the pentiptycene units. Enhanced water/salt permeability selectivity of PENT-BP(H) series was also observed due to a significantly higher diffusivity selectivity. At comparable water permeance (P w D ~ 8 X 10 -6 cm 2 /s), the salt rejection of PENT-BP (H) copolymers obtained from dead-end filtration reached 91–93% at 400 psi, higher than that of a corresponding BPS(H) series. This study suggests that incorporation of iptycene moieties into polymer backbone is an effective strategy to enhance desalination membrane performance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Evidence for the stability of ultrahydrous stishovite in Earth’s lower mantle

The distribution and transportation of water in Earth’s interior depends on the stability of water-bearing phases. The transition zone in Earth’s mantle is generally accepted as an important potential water reservoir because its main constituents, wadsleyite and ringwoodite, can incorporate weight percent levels of H 2 O in their structures at mantle temperatures. The extent to which water can be transported beyond the transition zone deeper into the mantle depends on the water carrying capacity of minerals stable in subducted lithosphere. Stishovite is one of the major mineral components in subducting oceanic crust, yet the capacity of stishovite to incorporate water beyond at lower mantle conditions remains speculative. Here, we combine in situ laser heating with synchrotron X-ray diffraction to show that the unit cell volume of stishovite synthesized under hydrous conditions is ~2.3 to 5.0% greater than that of anhydrous stishovite at pressures of ~27 to 58 GPa and temperatures of 1,240 to 1,835 K. Our results indicate that stishovite, even at temperatures along a mantle geotherm, can potentially incorporate weight percent levels of H 2 O in its crystal structure and has the potential to be a key phase for transporting and storing water in the lower mantle.

58 GEOSCIENCES↗
DOE OSTI2026

Conformational Isomerization of Imide Anions Governs Solvation and Transport in Water-in-Salt Electrolytes

The behavior of highly concentrated electrolytes departs radically from the dilute-solution theory, yet the molecular origin of this transformation remains unresolved. Here, we identify the conformational isomerization of molecular ions as a decisive, previously unrecognized control parameter governing structure and transport in crowded aqueous electrolytes. Across a series of fluorosulfonimide anions, we show that increasing concentration drives a collective shift from extended transoid to compact cisoid conformers, revealed by small-angle X-ray scattering, vibrational spectroscopy, pulsed-field gradient NMR, and molecular dynamics simulations. This conformational transition triggers a collapse of the hydrogen-bonded water network and the emergence of densely packed ionic domains with confined water, producing a qualitative change in Li+ transport from solvent-mediated diffusion to network-confined hopping. Anion size and asymmetry systematically tune the onset of this transition, demonstrating that molecular geometry dictates mesoscale organization and dynamics in the ion-rich regime. Our results establish ion conformation, not merely composition or coordination, as a fundamental thermodynamic variable in concentrated solutions, providing a chemical framework that unifies solvation structure and transport in water-in-salt electrolytes and suggesting new principles for designing dense ionic media.

Nguyen, Huong TD↗
DOE OSTI2021

Insights into the rapid two-phase transport dynamics in different structured porous transport layers of water electrolyzers through high-speed visualization

In proton exchange membrane electrolyzer cells (PEMECs), maintaining efficient two-phase transport is one of the most important functions of porous transport layers (PTLs). To enhance the two-phase transport in PTLs, thin/titanium liquid/gas diffusion layers (TT-LGDLs) are introduced in PEMECs, and their difference from the conventional Ti felt PTLs are analyzed in-situ through high-speed and microscale visualization and electrochemical characterizations. The visualization results show that unfavorable large slugs can be greatly reduced in the PEMEC with a TT-LGDL compared to the PEMEC with a Ti felt PTL. More importantly, the recovery capability of water starvation with different PTLs is studied. After water starvation, the PEMEC with the TT-LGDL can recover the water starvation much more rapidly than the Ti felt cell, benefiting from its short and straight-through flow paths. Furthermore, the TT-LGDL tends to generate oxygen bubbles that are almost six times smaller and 236 times more frequently than the Ti felt PTL, indicating significantly boosted removal efficiency of produced oxygen and PEMEC performance. Finally, this study offers new insights into the dynamic processes of two-phase transport and the recovery capability of water starvation for different PTLs, which will provide valuable guidance for further optimization of PTLs and performance enhancement of PEMECs.

08 HYDROGEN↗
DOE OSTI2024

Nanochannel electrodes facilitating interfacial transport for PEM water electrolysis

Proton-exchange membrane water electrolyzers (PEMWEs) are a promising technology for green hydrogen production; however, interfacial transport behaviors are poorly understood, hindering device performance and longevity. Here, we first utilized finite-gap electrolyzer to demonstrate the possibility of proton transfer through water in PEMWEs. The measured high-frequency resistances (HFRs) exhibit a linear trend with increasing gap distance, where extrapolation shows a lower value compared with HFRs in regular zero-gap electrolyzers, indicating that ohmic resistance could be further reduced. We introduce nanochannels to facilitate mass transport, as evidenced by both liquid-fed and vapor-fed electrolysis. Nanochannel electrodes achieve a voltage reduction of 190 mV at 9 A·cm –2 compared with the Ir-PTEs without nanochannels. Furthermore, nanochannel electrodes show negligible degradation through 100,000 accelerated-stress tests and over 2,000 h of operation at 1.8 A·cm –2 with a decay rate of 11.66 μV·h –1 . These results provide new insights into localized transport dynamics for PEMWEs and highlight the significance of interfacial engineering for electrochemical devices.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Water-Assisted Proton Transport in Confined Nanochannels

Hydrated excess protons under hydrophobic confinement are a critical component of charge transport behavior and reactivity in nanoporous materials and biomolecular systems. In this study, excess proton confinement effects are computationally investigated for sub-2 nm hydrophobic nanopores by varying the diameters (d = 0.81, 0.95, 1.09, 1.22, 1.36, 1.63, and 1.90 nm), lengths (l ~3 and ~5 nm), curvature, and chirality of cylindrical carbon nanotube (CNT) nanopores. CNTs with a combination of different diameter segments are also explored. The spatial distribution of water molecules under confinement is diameter-dependent; however, proton solvation and transport are consistently found to occur in the water layer adjacent to the pore wall, showing an “amphiphilic” character of the hydrated excess proton hydronium-like structure. The proton transport free energy barrier also decreases significantly as the nanopore diameter increases and proton transport becomes almost barrierless in the d > 1 nm nanopores. Among the nanopores studied, the Zundel cation (H 5 O 2 + ) is populated only in the d = 0.95 nm CNT (7,7) nanopore. The presence of the hydrated excess proton and K + inside the CNT (7,7) nanopore induces a water density increase by 40 and 20%, respectively. The K + transport through CNT nanopores is also consistently higher in the free energy barrier than proton transport. Interestingly, the evolution of excess protonic charge defect distribution reveals a “frozen” single water wire configuration in the d = 0.81 nm CNT (6,6) nanopore (or segment), through which hydrated excess protons can only shuttle via the Grotthuss mechanism. Vehicular diffusion becomes relevant to proton transport in the “flat” free energy regions and in the wider nanopores, where protons do not primarily shuttle in the axial direction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗