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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 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Aqueous Zr/Hf IV ‐Oxo Cluster Speciation and Separation

Abstract Many industrial separations of chemically‐similar elements are achieved by solvent extraction, exploiting differences in speciation and solubility across aqueous‐organic interfaces. We recently identified [OM 4 (OH) 6 (SCN) 12 ] 4− (OM 4 , M=Zr/Hf IV ) tetrahedral oxoclusters as the main species in industrial processes that produce nuclear‐grade Zr and Hf from crude ore. However, isostructural/isoelectronic OM 4 ‐oxoclusters do not explain selective extraction of Hf into the organic phase. Here we have characterized heterometal Hf−Zr clusters in solution and the solid‐state yielding key information about their fundamentally different chemistry that engenders separation. Clusters prepared with both ammonium (industrial process) and tetramethylammonium counter cations revealed that 1) heterometal clusters (instead of a mixture of homometal clusters) assemble, and 2) Hf‐rich OM 4 selectively precipitates over Zr‐rich OM 4 , providing a separation process that does not require an organic extractant. Mass spectrometry, small‐angle X‐ray scattering, solution‐state 1 H nuclear magnetic resonance (NMR) spectroscopy, and solid‐state 17 O NMR evidence both mixed‐metal speciation and selective Hf‐precipitation. Raman spectroscopy suggests greater Zr‐ligand lability than Hf‐ligand lability, consistent with higher aqueous solubility of Zr‐rich clusters, enabling both extraction and precipitation‐based separation. Fundamentally, we also identify a key difference between these chemically similar elements that has enabled diversification of Zr‐polyoxocation chemistry over the last decade, while Hf‐polyoxocation chemistry lags.

Roseborough, Alexander [Department of Chemistry Or↗
DOE OSTI2021

Amino‐Functionalised Hybrid Ultramicroporous Materials that Enable Single‐Step Ethylene Purification from a Ternary Mixture

Abstract Pyrazine‐linked hybrid ultramicroporous (pore size <7 Å) materials (HUMs) offer benchmark performance for trace carbon capture thanks to strong selectivity for CO 2 over small gas molecules, including light hydrocarbons. That the prototypal pyrazine‐linked HUMs are amenable to crystal engineering has enabled second generation HUMs to supersede the performance of the parent HUM, SIFSIX‐3‐Zn , mainly through substitution of the metal and/or the inorganic pillar. Herein, we report that two isostructural aminopyrazine‐linked HUMs, MFSIX‐17‐Ni (17=aminopyrazine; M=Si, Ti), which we had anticipated would offer even stronger affinity for CO 2 than their pyrazine analogs, unexpectedly exhibit reduced CO 2 affinity but enhanced C 2 H 2 affinity. MFSIX‐17‐Ni are consequently the first physisorbents that enable single‐step production of polymer‐grade ethylene (>99.95 % for SIFSIX‐17‐Ni ) from a ternary equimolar mixture of ethylene, acetylene and CO 2 thanks to coadsorption of the latter two gases. We attribute this performance to the very different binding sites in MFSIX‐17‐Ni versus SIFSIX‐3‐Zn .

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

Porous Covalent Organic Polymers for efficient Fluorocarbon-based Adsorption Cooling

Adsorption-based cooling is an energy-efficient renewable-energy technology that can be driven using low-grade industrial waste heat and/or solar heat. Here, we report the first exploration of fluorocarbon adsorption using porous covalent organic polymers (COPs) for this cooling application. High fluorocarbon R134a equilibrium capacities and unique overall linear-shaped isotherms are revealed for the materials, namely COP-2 and COP-3. The key role of mesoporous defects on this unusual adsorption behavior was demonstrated by molecular simulations based on atomistic defect-containing models built for both porous COPs. Analysis of simulated R134a adsorption isotherms for various defect-containing atomistic models of the COPs shows a direct correlation between higher fluorocarbon adsorption capacities and increasing pore volumes induced by defects. Combined with their high porosities, excellent reversibility, fast kinetics, and large operating window, these defect-containing porous COPs are promising for adsorption-based cooling applications.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

Efficient Polyester Hydrogenolytic Deconstruction via Tandem Catalysis

Using a mechanism-based solvent-free tandem catalytic approach, commodity polyester plastics such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN) are rapidly and selectively deconstructed by combining the two air- and moisture-stable catalysts, Hf(OTf) 4 and Pd/C, under 1 atm H 2 , affording terephthalic acid (or naphthalene dicarboxylic acid for PEN) and ethane (or butane for PBT) in essentially quantitative yield. This process is effective for both laboratory grade and waste plastics, and comingled polypropylene remains unchanged. Combined experimental and DFT mechanistic analyses indicate that Hf(OTf) 4 catalyzes a mildly exergonic retro-hydroalkoxylation reaction in which an alkoxy C-O bond is first cleaved, yielding a carboxylic acid and alkene, and this process is closely coupled to an exergonic olefin hydrogenation step, driving the overall reaction forward.

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

Upcycling of Waste Plastics into Carboxylic Acids for Biodegradable Surfactants

This work outlines a process for producing high‐purity (>95%) carboxylate surfactants from post‐consumer recycled high‐density polyethylene (PCR‐HDPE). The approach involves the thermal depolymerization of PCR‐HDPE via pyrolysis, followed by fractional distillation to isolate C9–C14 olefins. These olefins undergo hydroformylation using cobalt carbonyl catalysts to generate aldehydes, which are subsequently oxidized to carboxylic acids using Pinnick oxidation under mild aqueous‐phase conditions. Neutralization of the resulting carboxylic acids with sodium hydroxide produces plastic‐derived carboxylate surfactants (PDCs) in the form of sodium carboxylates. Subsequent purification steps ensure surfactant‐grade purity and enable accurate assessment of physicochemical properties. The resulting PDCs are evaluated for critical micelle concentration (CMC), foamability, surface tension reduction, and calcium ion tolerance, demonstrating competitive behavior with conventional anionic carboxylate surfactants. This route provides a sustainable alternative for surfactant production, reducing reliance on fossil‐derived feedstocks and valorizing plastic waste streams through chemical upcycling.

Biodegradable surfactants↗
DOE OSTI2023

Valorization of mullet roe by‐products for the production of polyunsaturated fatty acids rich oils

Abstract This work examines the potential valorization of mullet roe by‐products for the production of mullet roe oil using mild processes. Three different extraction methods with potential of scale‐up for the food industry, namely pressure (PE), supercritical fluid extraction (SFE), and solvent extraction (SE) are examined. Mild temperature conditions to prevent oil oxidation and (wherever applicable) food‐grade solvents are used. The oil yield, the composition of oils in fatty acids by GC‐FID, the level of oil oxidation (peroxide value (PV), p‐anisidine value (AV), K 232 K 268 , TOTOX)) and the antioxidant activity (DPPH, ABTS) are determined. SE provided the highest oil recovery, followed by SFE and PE (68%, 28% and 10% respectively). The extracted oils had a high concentration of EPA and DHA and a total of 20.7%–24.3% of identified PUFAs among the fatty acids. Oxidation was the lowest in the SFE extracted oil followed by PE, PV was <2.5 meq O2 , AV≤10 and TOTOX <15 in all examined oil samples. Further research is needed to optimize processing conditions for the increase in oil recovery.

Kalogianni, Eleni P.↗
DOE OSTI2023

3D Carbon Coating Enabled High‐capacity and Stable Micro‐sized Silicon Suboxide‐graphite Blended Anodes for Practical Lithium‐ion Batteries

Abstract Silicon oxide (SiO x ) is a promising anode candidate of lithium‐ion batteries (LIBs) owing to its extremely high specific capacity. However, the low initial Coulombic efficiency (ICE) and rapid capacity degradation of SiO x , triggered by the enormous volume variation upon repeated (de)lithiation, gravely hinder its practical use. Herein, two mass‐produced micro‐sized SiO x @C composites with obviously different morphologies for commercial LIBs are reported. Particularly, the SiO x ‐graphite blended anode (SiO x @3D‐G‐Gr) based on SiO x wrapped by three‐dimensional (3D) carbon layers (SiO x @3D‐G) exhibits a capacity of 519 mAh g −1 , an ICE of 90.0 % and a capacity retention of 83.4 % at 0.2 C over 100 cycles. which is far exceeding its counterpart SiO x @C‐H‐Gr (65.7 %). The obtained impressive properties of SiO x @3D‐G originate from the critical contribution of 3D carbon layers, which serves as the effective stress buffer and protective layer as well as the strong networks for electron/Li + transport. Accordingly, the full‐cell based on SiO x @3D‐G‐Gr anode and commercial LiCoO 2 cathode delivers a capacity of 803 mAh and an excellent capacity retention of 95.6 % (616 mAh, 96.6 % for graphite, respectively) at 1 C over 100 cycles with a stabilized CE of nearly 100 %. The micro‐sized SiO x @3D‐G showing a promising prospect in the commercial‐grade anodes in LIBs.

Electrochemistry↗
DOE OSTI2024

Model acetylcholinesterase‐Fc fusion glycoprotein biotechnology system for the manufacture of an organophosphorus toxicant bioscavenging countermeasure

Abstract Organophosphate (OP) toxicants remain an active threat to public health and to warfighters in the military. Current countermeasures require near immediate administration following OP exposure and are reported to have controversial efficacies. Acetylcholinesterase (AChE) fused to the human immunoglobulin 1 (IgG1) Fc domain (AChE‐Fc) is a potential bioscavenger for OP toxicants, but a reproducible AChE‐Fc biomanufacturing strategy remains elusive. This report is the first to establish a comprehensive laboratory‐scale bioprocessing strategy that can reproducibly produce AChE‐Fc and AChE(W86A)‐Fc which is a mutated AChE protein with reduced enzymatic activity. Characterization studies revealed that AChE‐Fc and AChE(W86A)‐Fc are N ‐glycosylated dimeric fusion glycoproteins but only AChE‐Fc had the capability to bind to paraoxon (a model OP). This AChE‐Fc fusion glycoprotein bioprocessing strategy can be leveraged during industrial biomanufacturing development, while the research‐grade AChE‐Fc proteins can be used to determine the potential clinical relevance of the countermeasure against OP toxicants.

Biel, Thomas G.↗
DOE OSTI2020

A nomogram for prediction of stage III/IV gastric cancer outcome after surgery: A multicenter population‐based study

Abstract Most patients with gastric cancer (GC) are first diagnosed at stage III‐IV and surgery resection remains the primary therapeutic modality for these patients. However, clinical staging used for prediction of those patients provides limited information. We collected clinicopathological data and disease‐progression information from 508 patients with stage III‐IV GC at three Chinese hospitals and 1298 patients from the Surveillance, Epidemiology, and End Results database. Based on the stepwise multivariate regression model, we constructed a novel nomogram to predict overall survival (OS). The performance of discrimination for this model was measured using Harrell's concordance index (C‐index) and receiver‐operating characteristic curve (ROC), and was validated using calibration plots. Multivariate Cox regression analyses showed that tumor size, age at diagnosis, N stage, tumor grade, and distant metastases were outstanding independent prognostic factors of stage III‐IV GC. We developed a nomogram based on these five prognostic predictors. In the training set, the C‐index of the nomogram was 0.645 (95% CI: 0.611‐0.679), which was higher than that of the American Joint Committee on Cancer TNM system alone (sixth TNM: 0.544; seventh TNM: 0.575; eighth TNM: 0.568). Similar results were observed in validation cohort. Moreover, calibration blots demonstrated good consistency between the actual and predicted OS probabilities. According to the nomogram, GC individuals could be classified into three groups (low‐, middle‐, and high‐risk) ( P < .001). Our nomogram complements the current staging system for prediction of individual prognosis with stage III‐IV GC, and may be helpful for making individualized treatment decisions.

Gao, Zhiying↗
DOE OSTI2025

Sustainable Graphite and Jet Fuel from Biorefinery Residue

Abstract Battery‐grade graphite and aviation fuel are traditionally produced from non‐renewable, fossil carbon feedstocks and result in substantial greenhouse gas emissions. Biomass holds exciting potential as a renewable and sustainable feedstock for the production of graphite and aviation fuel, but challenges exist including the necessity of a catalyst when producing graphite and low selectivity when producing aviation fuel. A process to convert a biomass‐derived feedstock into graphite without the use of a catalyst and fuels with high selectivity towards sustainable aviation fuel (SAF) is innovated. Heavy bio‐oil undergoes a conversion process similar to the commercial production of synthetic graphite including coking at 500 °C, calcination at 1000 °C, and graphitization at 2800 °C. The resulting biographite exhibits excellent performance in lithium‐ion battery configurations with specific capacity of ~330 mAh g −1 and a 96.8 % capacity rebound after high rate cycling. The liquid hydrocarbon co‐product from coking is suitable for hydrotreating into SAF. The aviation fuel fraction (70 wt % of the fuel produced) meets ASTM standards and is composed primarily of cycloalkanes (~80 wt %) which improves energy density compared to paraffins produced by other SAF pathways and may replace aromatics for elastomer swelling in traditional jet fuel with less soot production.

09 BIOMASS FUELS↗
DOE OSTI2025

Hydrolysis of Polyamide 6 to ε‐Caprolactam over Titanium Dioxide

Polyamides (PAs) are an important component of discarded textiles and food packaging. Chemical recycling can recover PA monomers, enabling repolymerization to produce virgin-grade PA. However, contemporary PA chemical recycling methods employ homogeneous catalysts that are hard to separate. Anatase TiO 2 is reported as a catalyst for PA6 hydrolysis at 270 °C for 0.5 h, achieving a maximum ε-caprolactam (CL) yield of 81% (limited by thermodynamic equilibrium). The CL yield decreases upon catalyst reuse, due to loss of catalyst surface area induced by significant changes in catalyst crystallinity and texture. Pretreating the catalyst hydrothermally stabilizes it against morphological changes, yielding repeatable CL yields. Altogether, this study discloses a heterogeneous catalyst capable of producing repeatable equilibrium CL yields via PA6 hydrolysis under industrially relevant reaction temperatures and times (<3 h, 250–330 °C).

depolymerization↗
DOE OSTI2025

Linking Lattice Strain and Fractal Dimensions to Non‐monotonic Volume Changes in Irradiated Nuclear Graphite

Graphite's resilience to high temperatures and neutron damage makes it vital for nuclear reactors, yet irradiation alters its microstructure, degrading key properties. We used small- and wide-angle X-ray scattering to study neutron-irradiated fine-grain nuclear graphite (Grade G347A) across varied temperatures and fluences. Results show significant shifts in internal strain and porosity, correlating with radiation-induced volume changes. Notably, porosity volume distribution (fractal dimensions) follows non-monotonic volume changes, suggesting a link to the Weibull distribution of fracture stress.

X-ray scattering↗
DOE OSTI2021

Perceived Conflicts of Systems Engineering in Early-Stage Research and Development 1

Early Systems Research and Development (ESR&D) is one of the most crucial phases in the product development process. It both blends and blurs the lines between science and engineering, and requires a risk-based, disciplined, and graded approach to effectively manage scope, cost, and complexity of the final product. Many leaders, program managers, and scientists are unwilling to involve systems engineering because of the perception that systems engineering is heavily process oriented, adds unnecessary costs, and should be applied only to mature technologies. The value of systems engineering as applied to ESR&D is unclear to these key individuals. The unfortunate result is that system engineering is not applied to ESR&D. This results in R&D efforts that may have solved the wrong problem, selected the wrong architecture, require technical rework, have difficulty transitioning later maturity levels, and result in higher R&D costs and extended development timelines. This work discusses the difficulty of introducing systems engineering to the research and early development process and their inclination perspectives of researchers, engineers, and managers. The article shall offer potential means to manage the cultural transformation of early adoption of right-sized systems engineering in ESR&D and reverse the attitudinal positions.

42 ENGINEERING↗
DOE OSTI2021

Fabrication and characterization of dextran/zein hybrid electrospun fibers with tailored properties for controlled release of curcumin

Abstract BACKGROUND In recent years, there has been considerable interest in the use of biopolymer electrospun nanofibers for various food applications due to the biocompatibility, biodegradability, and high loading capacity. Herein, we fabricated and characterized novel hybrid electrospun fibers from dextran (50%, w/v ) and zein (0–30%, w/v ) solutions, and the effects of various zein concentrations on the properties of the hybrid electrospun fibers were investigated. RESULTS When zein was added at low concentrations (5% and 10%), dextran and zein showed poor miscibility, as reflected by significantly decreased viscosity of the solutions, and the poor mechanical properties of the derived fiber membranes. When zein was added at medium concentrations (15–25%), hydrogen bonds were formed between dextran and zein molecules, as indicated by the red shift of Fourier‐transform infrared bands and β‐sheet to α‐helix structural transformations. The fiber membranes electrospun from a solution with 25% zein showed the most hydrophobic surface, with a water contact angle of 116.9°. The homogenous dispersion of dextran and zein resulted in improved mechanical properties for fibers electrospun from a solution with 30% zein. Curcumin encapsulating dextran/zein electrospun fibers exhibited effective radical scavenging activity and ferric reducing power, along with the desired controlled release behavior for curcumin delivery. CONCLUSION Food grade dextran/zein hybrid electrospun fibers demonstrated tunable properties, and appear to be promising as delivery systems for bioactive and edible antimicrobial food packaging. © 2021 Society of Chemical Industry.

Luo, Shiyuan↗
DOE OSTI2021

Long‐term drench of exopolysaccharide from Leuconostoc pseudomesenteroides XG5 protects against type 1 diabetes of NOD mice via stimulating GLP ‐1 secretion

Abstract BACKGROUND Type 1 diabetes is an autoimmune disease that results in the specific destruction of insulin‐producing beta cells in the pancreas. The aim of this study was to investigate the mechanism of exopolysaccharide from Leuconostoc pseudomesenteroides XG5 (XG5 EPS) against type 1 diabetes. RESULTS Long‐term drench of XG5 EPS delayed the onset of autoimmune diabetes and had fewer islets with high‐grade infiltration (an insulitis score of 3 or 4) than untreated NOD mice. Oral administration of 50 mg kg −1 d −1 XG5 EPS increased the insulin and glucagon‐like peptide‐1 (GLP‐1) levels of serum, stimulated GLP‐1 secretion and upregulated gcg mRNA expression of colon in NOD mice. Moreover, oral administration of 50 mg kg −1 d −1 XG5 EPS significantly increased total short‐chain fatty acids levels in the colon contents, especially those of acetic acid and butyric acid. In NCI‐H716 cells, 500 and 1000 μmol L −1 sodium butyrate promoted the secretion of GLP‐1 and upregulated the mRNA expression of gcg and PC3 , while XG5 EPS and sodium acetate did not stimulate the GLP‐1 secretion. Therefore, long‐term drench of XG5 EPS delayed the onset of autoimmune diabetes, which may be directly correlated with the increase of butyrate in the colon of NOD mice. CONCLUSION Long‐term drench of 50 mg kg −1 d −1 XG5 EPS promoted the expression and secretion of GLP‐1 by increasing the production of butyric acid, thereby delaying T1D onset in NOD mice. © 2021 Society of Chemical Industry.

Pan, Lei↗
DOE OSTI2022

Oxides and Nitrides with Asymmetric Pore Structure from Block Copolymer Co–Assembly and Non–Solvent Induced Phase Separation

Materials combining an asymmetric pore structure with mesopores everywhere enable high surface area accessibility and fast transport, making them attractive for e.g., energy conversion and storage applications. Block copolymer (BCP)/inorganic precursor co-assembly combined with non-solvent induced phase separation (NIPS) provides a route to materials in which a mesoporous top surface layer merges into an asymmetric support with graded porosity along the film normal and mesopores throughout. Here, the co-assembly and non-solvent-induced phase separation (CNIPS) of poly(isoprene)-b-poly(styrene)-b-poly(4-vinylpyridine) (ISV) triblock terpolymer and titanium dioxide (TiO 2 ) sol-gel nanoparticlesare reported. Heat-treatment in air results in free-standing asymmetric porous TiO 2 . Further thermal processing in ammonia results in free-standing asymmetric porous titanium nitride (TiN). processing changes alter structural membrane characteristics is demonstrated. Changing the CNIPS evaporation time results in various membrane cross-sections ( finger-like to sponge-like). Further, oxide and nitride material composition, crystallinity, and porosity are tuned by varying thermal processing conditions. Finally, thermal processing condition effects are probed on phase-pure asymmetric nitride membrane behavior using cyclic voltammetry to elucidate their influence, e.g., on specific capacitance. Results provide further insights into improving asymmetric and porous materials for applications including energy conversion and storage, separation, and catalysis and motivate a further expansion of CNIPS to other (in)organic materials.

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

International collaboration framework for the calculation of performance loss rates: Data quality, benchmarks, and trends (towards a uniform methodology)

Abstract The IEA PVPS Task 13 group, experts who focus on photovoltaic performance, operation, and reliability from several leading R&D centers, universities, and industrial companies, is developing a framework for the calculation of performance loss rates of a large number of commercial and research photovoltaic (PV) power plants and their related weather data coming across various climatic zones. The general steps to calculate the performance loss rate are (i) input data cleaning and grading; (ii) data filtering; (iii) performance metric selection, corrections, and aggregation; and finally, (iv) application of a statistical modeling method to determine the performance loss rate value. In this study, several high‐quality power and irradiance datasets have been shared, and the participants of the study were asked to calculate the performance loss rate of each individual system using their preferred methodologies. The data are used for benchmarking activities and to define capabilities and uncertainties of all the various methods. The combination of data filtering, metrics (performance ratio or power based), and statistical modeling methods are benchmarked in terms of (i) their deviation from the average value and (ii) their uncertainty, standard error, and confidence intervals. It was observed that careful data filtering is an essential foundation for reliable performance loss rate calculations. Furthermore, the selection of the calculation steps filter/metric/statistical method is highly dependent on one another, and the steps should not be assessed individually.

14 SOLAR ENERGY↗
DOE OSTI2023

Analysis of degradation products in thermally treated TATB

Delineating the chemical composition of TATB (1,3,5-triamino-2,4,6-trinitrobenzene) residues produced from the exposure to abnormal thermal environments should lead to a better understanding of the decomposition paths. Identifying and quantifying each compound in thermally produced residues, monitors which compounds are degrading or forming along the decomposition route, as well as providing input for the kinetic models of those pathways. Here, in this paper, we report the methodology of isolating, identifying, and where possible, quantifying soluble compounds present in solid residues of thermally treated TATB (330 °C for tens of minutes). Samples were extracted with DMSO, separated using chromatography, and quantified using their absorption at 354 nm. Identification of unknown compounds was accomplished using high resolution mass spectrometry. TATB, F1 (diamino-dinitro-benzofurazan), HO-TATB (2,4,6-triamino-1-hydroxyl-3,5-dinitrobenzene), and T4A (1-chloro-3,5-dinitro-2,4,6-triaminobenzene) were trace compounds detected in the unreacted TATB. Ten more compounds that formed in the residues were structurally identified including F2 (amino-nitro-difurazan). Several more compounds were observed but not completely identified. We propose possible structures for the unknowns. Of the compounds formed, F1 was the most abundant compound reaching 4.5 % by weight of the degraded solid sample. Other degradation compounds were estimated to sum to trace levels, well below 1 %. Most compounds were new, having not been detected and identified in previous studies of production grade and thermally aged TATB. Many compounds only reached detectable concentrations after several min of thermal exposure.

36 MATERIALS SCIENCE↗