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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 1,729 records · Page 96
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Genetically engineered Foot and Mouth Disease Virus and related proteins, polynucleotides, compositions, methods and systems

Genetically engineered Foot and Mouth Disease Virus (FMDV) and related engineered proteins and polynucleotides, nanolipoprotein particles, compositions, methods and systems are described. The genetically engineered FMDV is modified by the strategic insertion of a protein tag into select regions of the FMDV genome which encode viral proteins that are exposed on the surface of the FMDV viral capsid. The inserted protein tag is displayed as a decoration or attachment on the viral capsid surface.

Rieder, Aida Elizabeth↗
DOE OSTI2020

The Effect of Artificial SEIs on Lithium Metal Anode Morphology and Conductivity

Lithium metal has often been termed the “holy grail” of battery technology, due to its high capacity (2,061 mAh/cm3) and low electrochemical potential (-3.04 V vs. SHE). However, lithium’s beneficially low potential also causes it to be highly reactive in the presence of organic solvents, making it difficult to harness the high energy capabilities for rechargeable batteries. Common failure of lithium metal batteries occurs by rapid dendrite growth leading to a hazardous short-circuit. Various methods have been brought forth to better understand the fundamental mechanisms of lithium metal batteries, as well as modifications made to better stabilize lithium metal. A common route of modification is done through interface engineering, with attempts to artificially provide a stable, homogeneous solid-electrolyte interface (SEI). The stability of the SEI has direct effects on the heterogeneity of the electrode surface, which initiates a waterfall effect of for progressive reactions such as dendrite growth, dead lithium accumulation, and electrolyte consumption. This work aims to produce a mixed LiI-LiF artificial SEI to improve ionic conductivity while retaining a high elastic modulus.

25 ENERGY STORAGE↗
DOE OSTI2023

Genetically engineered foot and mouth disease virus and related proteins, polynucleotides, compositions, methods and systems

Genetically engineered Foot and Mouth Disease Virus (FMDV) and related engineered proteins and polynucleotides, nanolipoprotein particles, compositions, methods and systems are described. The genetically engineered FMDV is modified by the strategic insertion of a protein tag into select regions of the FMDV genome which encode viral proteins that are exposed on the surface of the FMDV viral capsid. The inserted protein tag is displayed as a decoration or attachment on the viral capsid surface.

Rieder, Aida E.↗
DOE OSTI2025

Multi-scale modeling of wastage layer formation in metallic fuel cladding

Fuel-cladding chemical interaction (FCCI) is a major concern for U-Zr metallic fuels' performance, primarily due to the formation of a brittle layer (wastage) in the cladding. This brittle layer, resulting from intermetallic compounds between cladding constituents Fe, Cr, and lanthanide fission products, significantly impacts the cladding's mechanical integrity. Recent efforts focus on developing a mechanistic modeling framework to understand lanthanide production, transport to the fuel-cladding interface, and phase transformation to intermetallic phases. A multi-scale computational approach has been used to calculate lanthanide transport rates, with atomistic calculations determining Nd diffusivities through the solid fuel matrix and along pore surfaces. These diffusivities inform a mesoscale model to determine an effective diffusion coefficient, accounting for porosity and infiltration with bond sodium. This effective diffusivity is used in engineering-scale simulations via the BISON fuel performance code, which has been validated against EBR-II and FFTF reactor experiments.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2016

Effects of equivalence ratio variations on turbulent flame speed in lean methane/air mixtures under lean-burn natural gas engine operating conditions

Direct numerical simulations of turbulent premixed air flames were carried out using an inflow-outflow configuration to study the effects of equivalence ratio on the turbulent flame speed in lean mixtures. The inflow velocity was dynamically adjusted at a run-time to stabilize the flame brush location within the computational domain. Linear forcing was applied to maintain the turbulent intensities at desired levels. Numerous equivalence ratios near the lean limit were selected for the same turbulence properties and the normalized turbulent flame speed was shown to be a function of the equivalence ratio. Simulations were performed for over 80 eddy turnover times with the turbulent flame speed obtained by averaging the inflow velocity. Results revealed that the equivalence ratio does not have an explicit effect on the normalized turbulent flame speed over the lean limit. Analysis of flame surface area showed that the surface wrinkling produced by eddies of varying scales was not influenced by the change in equivalence ratios when the Karlovitz and Damkohler numbers are fixed. Lastly based on the flame surface statistics flame surface normal is preferentially parallel to the most compressive strain rate direction for all equivalence ratios.

03 NATURAL GAS↗
DOE OSTI2019

GPTMS-Modified Bredigite/PHBV Nanofibrous Bone Scaffolds with Enhanced Mechanical and Biological Properties

Bioceramic nanoparticles with high specific surface area often tend to agglomerate in the polymer matrix, which results in undesirable mechanical properties of the composites and poor cell spreading and attachment. In the present work, bredigite (BR) nanoparticles were modified with an organosilane coupling agent, 3-glycidoxypropyltrimethoxysilane (GPTMS), to enhance its dispersibility in the polymer matrix. The polyhydroxybutyrate-co-hydroxyvaletare (PHBV) nanofibrous scaffolds containing either bredigite or GPTMS-modified bredigite (G-BR) nanoparticles were fabricated using electrospinning technique and characterized using scanning electron microscopy, transmission electron microscopy, and tensile strength. Results demonstrated that modification of bredigite was effective in enhancing nanoparticle dispersion in the PHBV matrix. PHBV/G-BR scaffold showed improved mechanical properties compared to PHBV and PHBV/BR, especially at the higher concentration of nanoparticles. In vitro bioactivity assay performed in the simulated body fluid (SBF) indicated that composite PHBV scaffolds were able to induce the formation of apatite deposits after incubation in SBF. From the results of in vitro biological assay, it is concluded that the synergetic effect of BR and GPTMS provided an enhanced hFob cells attachment and proliferation. The developed PHBV/G-BR nanofibrous scaffolds may be considered for application in bone tissue engineering.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Attempts to improve the H{sub 2}S sensitivity of TiO{sub 2} films

We report the pulsed laser deposited titanium oxide thin film for H{sub 2}S gas sensing. The surface and bulk electronic structure is revealed using XPS technique. These TiO{sub 2} films showed very good selectivity to H{sub 2}S with response of around ~ 60% at 200°C operating temperature. In order to improve the sensor response so as to realize the technological application, we hereby attempted bi-directional efforts as (i) Nb-doping and (ii) defects engineering in the TiO{sub 2} film. It is revealed that Nb-doping reduces response however defect engineering improves the same.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2023

Composite Lithium Metal Structure to Mitigate Pulverization and Enable Long‐Life Batteries

In lithium metal batteries, non‐uniform stripping of lithium results in pit formation, which promotes subsequent non‐uniform, dendritic deposition. This viscous cycle leads to pulverization of lithium which promotes cell shorting or capacity degradation, symptoms further exaggerated by high electrode areal loading and lean electrolytes. Here, to address this challenge, a composite lithium metal anode is engineered that contains uniformly distributed, nanometer‐sized carbon particles. This composite lithium is shown to strip more uniformly since the growth of non‐uniform pits is intercepted by the carbon particles. This mechanism is corroborated by a continuum electrochemical model. Subsequent lithium deposition on carbon particles is also found to be more uniform than on the surface with irregular pits. Notably, the pulverization rate of composite lithium is 26 times slower than that of commercial lithium. Moreover, in a Li‐S battery with sulfurized polyacrylonitrile cathode, the use of the composite anode extends the cycle life by three times when the areal capacity is 8 mAh cm −2 . The approach of using an engineered lithium composite structure to address challenges during both stripping and plating can inform future designs of lithium metal anodes for high areal capacity operations.

high areal capacity↗
DOE OSTI2021

Corrosion Detection LDRD Seedling (Final Report)

Automation techniques for recognizing material defects are very common in fields like infrastructure survey and civil engineering; however, the defects are usually easily distinguishable from their background, on a larger scale (e.g. cement bridges), and very specific. Extracting information about a defect that is near or equal to the background of the data can be extremely difficult. Images with heavy background corrosion, pitting, cracking, and man-made defects (such as welding) makes extracting information on a specific defect near-impossible. This is especially true when the defect is on the micron level and the dynamic range of your image taking instrument is low. So, a simplified, Java-based Fiji™ (ImageJ) defect detection program, dependent on a ‘flag’ system, was proposed for data that has a micron level hairline crack that is near or equal to the background. The utilization of the built-in functions, plugins, and macro scripting capability of the Java-based software sends a series of flags to the user that help to identify if the surface contains a defect of interest and to characterize that defect.

42 ENGINEERING↗
DOE OSTI2019

Tuning Li 2 O 2 Formation Routes by Facet Engineering of MnO 2 Cathode Catalysts

In lithium-oxygen batteries, the solubility of LiO 2 intermediates in the electrolyte regulates the formation routes of the Li 2 O 2 discharge product. High-donor-number electrolytes with a high solubility of LiO 2 tend to promote the formation of Li 2 O 2 large particles following the solution route, which eventually benefits the cell capacity and cycle life. Here, we propose that facet engineering of cathode catalysts could be another direction in tuning the formation routes of Li 2 O 2 . In this work, fi-MnO 2 crystals with high occupancies of {111} or {100} facets were adopted as cathode catalysts in Li-O 2 batteries with a tetra(ethylene)glycol dimethyl ether electrolyte. The {111}-dominated beta-MnO 2 catalyzed the formation of the Li 2 O 2 discharge product into large toroids following the solution routes, while {100}-dominated beta-MnO 2 facilitated the formation of Li 2 O 2 thin films through the surface routes. Further computational studies indicate that the different formation routes of Li 2 O 2 could be related to different adsorption energies of LiO 2 on the two facets of beta-MnO 2 . Our results demonstrate that facet engineering of cathode catalysts could be a new way to tune the formation route of Li 2 O 2 in a low-donor-number electrolyte. Here, we anticipate that this new finding would offer more choices for the design of lithium-oxygen batteries with high capacities and ultimately a long cycle life.

25 ENERGY STORAGE↗
DOE OSTI2025

Structural analysis of the NifL-NifA complex reveals the molecular basis of anti-activation of nitrogen fixation gene expression in Azotobacter vinelandii

Understanding the molecular basis of regulated nitrogen (N 2 ) fixation is essential for engineering N 2 -fixing bacteria that fulfill the demand of crop plants for fixed nitrogen, reducing our reliance on synthetic nitrogen fertilizers. In Azotobacter vinelandii and many other members of Proteobacteria, the two-component system comprising the anti-activator protein (NifL) and the Nif-specific transcriptional activator (NifA)controls the expression of nif genes, encoding the nitrogen fixation machinery. The NifL-NifA system evolved the ability to integrate several environmental cues, such as oxygen, nitrogen, and carbon availability. The nitrogen fixation machinery is thereby only activated under strictly favorable conditions, enabling diazotrophs to thrive in competitive environments. While genetic and biochemical studies have enlightened our understanding of how NifL represses NifA, the molecular basis of NifA sequestration by NifL depends on structural information on their interaction. Here, we present mechanistic insights into how nitrogen fixation is regulated by combining biochemical and genetic approaches with a low-resolution cryo-electron microscopy (cryo-EM) map of the oxidized NifL-NifA complex. Our findings define the interaction surface between NifL and NifA and reveal how this interaction can be manipulated to generate bacterial strains with increased nitrogen fixation rates able to secrete surplus nitrogen outside the cell, a crucial step in engineering improved nitrogen delivery to crop plants.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Apparatus for mixing fuel in a gas turbine nozzle

A fuel nozzle in a combustion turbine engine that includes: a fuel plenum defined between an circumferentially extending shroud and axially by a forward tube-sheet and an aft tube-sheet; and a mixing-tube that extends across the fuel plenum that defines a passageway connecting an inlet formed through the forward tube-sheet and an outlet formed through the aft tube-sheet, the mixing-tube comprising one or more fuel ports that fluidly communicate with the fuel plenum. The mixing-tube may include grooves on an outer surface, and be attached to the forward tube-sheet by a connection having a fail-safe leakage path.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2019

Highly sensitive SPR PCF biosensors based on Ag/TiN and Ag/ZrN configurations

We numerically present and analyze a surface plasmon resonance (SPR) bimetallic photonic crystal fiber (PCF) biosensor using full vectorial finite element method. The bimetallic configuration is based on Silver and (TiN or ZrN) as alternative plasmonic materials. The reported design relies on PCF with an external channel to house the analyte. The inner surface of the channel is coated by a silver layer followed by TiN or ZrN to protect the silver layer from oxidation. The proposed biosensor can be implemented to detect the unknown analytes, organic chemicals, biological analytes, and biomolecules via the sensitive resonant peaks to the analyte refractive index variations for both polarized modes with high linearity. In this study, a comparison is made between the Ag/TiN configuration and the Ag/ZrN counterpart in terms of sensitivity, losses, and linearity. The geometrical parameters are optimized to achieve high refractive index sensitivities of 7000 nm/RIU for quasi-transverse electric (TE) mode and 6900 nm/RIU for quasi-transverse magnetic (TM) mode, respectively for the Ag/TiN configuration. However, the quasi TE and quasi TM modes achieve high sensitivity of 5300 and 5400 nm/RIU, respectively using the Ag/ZrN configuration. The standard PCF fabrication technologies can be used to fabricate the proposed SPR PCF biosensors.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Study of Low Flow Rate Ladle Bottom Gas Stirring Using Triaxial Vibration Signals

Secondary steelmaking plays a great role in enhancing the quality of the final steel product. The metal quality is a function of metal bath stirring in ladles. The metal bath is often stirred by an inert gas to achieve maximum compositional and thermal uniformity throughout the melt. Ladle operators often observe the top surface phenomena, such as level of meniscus disturbance, to evaluate the status of stirring. However, this type of monitoring has significant limitations in assessing the process accurately especially at low gas flow rate bubbling. The present study investigates stirring phenomena using ladle wall triaxial vibration at a low flow rate on a steel-made laboratory model and plant scale for the case of the vacuum tank degasser. Cold model and plant data were successfully modeled by partial least-squares regression to predict the amount of stirring. In the cold model, it was found that the combined vibration signal could predict the stirring power and recirculation speed effectively in specific frequency ranges. Plant trials also revealed that there is a high structure in each data set and in the same frequency ranges at the water model. In the case of industrial data, the degree of linear relationship was strong for data taken from a single heat.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Hierarchical Defect Engineering for LiCoO 2 through Low-Solubility Trace Element Doping

Real-world industry-relevant battery composite electrodes are hierarchically structured. Their structural and chemical complexity is featured by ubiquitous multi-scale porosity and cracks, solid-solid and solid-liquid interfaces, compositional and redox heterogeneity, as well as lattice disordering and deformation. In particular for the active cathode particles, which are the fundamental building blocks for the energy reservoir, it is a consensus that these structural and chemical defects could have a profound impact on the battery performance. An in-depth understanding of the underlying mechanisms could critically inform the cathode material engineering, which would have a tremendous potential but remains a daunting challenge at present. In this work, we tackle this question by studying LiCoO 2 (LCO) with trace doping of Ti, which exhibits a low solubility in the LCO layered lattice. Additionally, we observed the spontaneous and heterogeneous segregation of the dopant (Ti) across a wide range of length scales. In addition to the modification of the particle surface and the buried grain boundaries within the particle, we reveal that the Ti doping has induced a significant amount of lattice distortions, which, in turn, promotes the robustness of the LCO lattice at high state of charge (above 4.5V). Our result formulates a multi-scale defect engineering strategy that could be applicable to the synthesis of a broad range of energy materials for applications in batteries and beyond.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Solvent‐Phobic and Ionophilic Carboxylated Polythiophene Layer for Fluoride‐Rich Cathode Electrolyte Interphase

Abstract One focal area of contemporary organic mixed ionic‐electronic conductor (OMIEC) research relates to utilization of dual‐conductive properties to enhance the ion/electron transfer kinetics for energy storage applications. Insight regarding OMIEC response toward the electrolyte anion and solvent used in lithium‐ion batteries (LIBs), however, is limited. Here, for the first time, the solvent‐phobic and ionophilic (SP‐IP) properties of the OMIEC, poly[3‐(potassium‐4‐butanoate)thiophene‐2,5‐diyl] (P3KBT), are revealed through comprehensive evaluation and characterization. The solvent‐phobic characteristics arise from the cooperation of dispersive interaction, polar interaction, and hydrogen‐bonding between P3KBT and electrolyte solvent. The ionophilic nature is driven by electrostatic interactions between P3KBT side chain carboxylate groups and LiPF 6 , and the reversible electrochemical doping/de‐doping of the polythiophene backbone with PF 6 ⁻ . The SP‐IP properties induce formation of a LiF‐ rich , Li 2 CO 3 ‐ limited cathode electrolyte interphase (CEI) layer when a P3KBT coating layer is applied to the active material surface, significantly improving half‐cell life to over 1500 cycles at 2C.

Ren, Haoze [Department of Chemical and Bimolecular↗
DOE OSTI2023

Electrokinetic comparison of CaF 2 and AgCl from a MDS perspective

CaF 2 has limited electrokinetic sensitivity to fluoride ions in solution and the positive CaF 2 surface charge is not reversed at high fluoride ion concentration. Similar insensitivity of surface charge to high fluoride ion concentration has been observed for other alkali and alkaline earth fluoride salts. On the contrary, chloride ions act as potential determining ions for AgCl and reverse the surface charge, as expected. FTIR-IRS results indicate that the AgCl/water interface has a water structure-breaking tendency, whereas the CaF 2 /water interface has a structure-making tendency. Here, it is speculated that the strong hydrogen bonding between fluoride ions and water prevents the accommodation of excess fluoride ions at surface lattice sites of fluorite, and therefore explains the low sensitivity of the fluorite surface charge sign and magnitude to fluoride ion concentration. However, this speculation has not been examined at the molecular level and is evaluated by molecular dynamics simulations (MDS) in the research presented in this paper. Higher hydrogen bond density at the CaF 2 mineral/water interface confirms that the water structure has stronger hydrogen bonding at both the CaF 2 mineral surface and with the F - ion in solution. In this way, the interaction of the F - ion with the CaF 2 surface is inhibited.

36 MATERIALS SCIENCE↗