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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 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Development of High Alumina Glass Property Data for Hanford High-Level Waste Glass Models - 16231

Roughly half of the projected Hanford high-level waste batches will have waste loadings limited by relatively high concentration of Al{sub 2}O{sub 3}. Individual glasses have been formulated and tested to demonstrate that it is possible to increase the loading of these high-Al{sub 2}O{sub 3} wastes in glass by as much as 50%. To implement such increases in waste loading in the Hanford Tank Waste Treatment and Immobilization Plant, the impact of composition on the properties of high-Al{sub 2}O{sub 3} waste glasses must be quantified in the form of validated glass property-composition models. To collect the data necessary for glass property-composition models, a multi-phase experimental approach was developed. In the first phase of the study, a set of 46 glass compositions were statistically designed to most efficiently backfill existing data in the composition region for high-Al{sub 2}O{sub 3} (15 to 30 wt%) waste glasses. The glasses were fabricated and key glass properties were tested: - Product Consistency Test (PCT) on quench (Q) and canister centerline cooled (CCC) samples - Toxicity Characteristic Leaching Procedure (TCLP) on Q and CCC samples - Crystallinity as a function of temperature (T) at equilibrium and of CCC samples - Viscosity and electrical conductivity as a function of T The measured properties of these glasses were compared to predictions from previously existing models developed over lower Al{sub 2}O{sub 3} concentration ranges. Areas requiring additional testing and modeling were highlighted. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

High pressure-high temperature phase diagram of an energetic crystal: Dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50)

Raman spectroscopy was used to examine the high pressure-high temperature structural and chemical stability of an insensitive, high-performance energetic crystal – dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50). The phase diagram was determined over 8 GPa and (293-760) K. Under isobaric heating, the melting/decomposition of TKX-50 is preceded by a transformation to two consecutive high-temperature intermediates; a lower-temperature intermediate – diammonium 5,5’-bistetrazole-1,1'-diolate, and a higher-temperature intermediate – dihydroxylammonium 5,5'-bistetrazolate and/or diammonium 5,5'-bistetrazolate. Pressure strongly increases the transition temperatures for these transformations and subsequent decomposition. As a result, significant increase in the chemical stability of TKX-50 and intermediates with pressure was attributed to a suppression of hydrogen-transfer.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Production of High Yield, Ultra‐Shallow Nitrogen‐Vacancy Centre Ensembles Through High Purity Forming gas Annealing

Dense, ultra‐shallow (<10 nm from the surface) ensembles of nitrogen‐vacancy (NV) centers in diamond are sought‐after for realising practical quantum sensing at the nanoscale. However, these ensembles typically suffer from reduced NV creation efficiency and spin coherence compared to their deeper and bulk counterparts. Consequently, most demonstrations in the literature to date have been restricted to using single NV centers with atypical coherence and charge stability properties not achievable across entire ensembles. Here, in this work, we demonstrate that controlled annealing in a high purity forming gas atmosphere improves near‐surface NV formation efficiency to over 20%. This environment preserves a high quality hydrogen termination throughout the anneal, avoiding material etching over many hours at temperatures up to 1100°C and possibly helping to suppress vacancy out‐diffusion. We show that high temperature annealing is especially vital for improving spin properties in high density, ultra‐shallow implanted samples due to the localised damage profiles produced. By allowing the formation of high yield NV ensembles with improved spin properties, the optimised forming gas anneal can facilitate the reliable production of more sensitive diamond sensors than have previously been accessible.

Healey, Alexander J. [Royal Melbourne Institute of↗
DOE OSTI2019

Localized High‐Concentration Electrolytes Boost Potassium Storage in High‐Loading Graphite

Abstract Reversible intercalation of potassium‐ion (K + ) into graphite makes it a promising anode material for rechargeable potassium‐ion batteries (PIBs). However, the current graphite anodes in PIBs often suffer from poor cyclic stability with low coulombic efficiency. A stable solid electrolyte interphase (SEI) is necessary for stabilizing the large interlayer expansion during K + insertion. Herein, a localized high‐concentration electrolyte (LHCE) is designed by adding a highly fluorinated ether into the concentrated potassium bis(fluorosulfonyl)imide/dimethoxyethane, which forms a durable SEI on the graphite surface and enables highly reversible K + intercalation/deintercalation without solvent cointercalation. Furthermore, this LHCE shows a high ionic conductivity (13.6 mS cm −1 ) and excellent oxidation stability up to 5.3 V (vs K + /K), which enables compatibility with high‐voltage cathodes. The kinetics study reveals that K + intercalation/deintercalation does not follow the same pathway. The potassiated graphite exhibits excellent depotassiation rate capability, while the formation of a low stage intercalation compound is the rate‐limiting step during potassiation.

Qin, Lei↗
DOE OSTI2025

Novel Zwitterionic Polyurethane-in-Salt Electrolytes with High Ion Conductivity, Elasticity, and Adhesion for High-Performance Solid-State Lithium Metal Batteries

This study presents a novel polymer-in-salt (PIS) zwitterionic polyurethane-based solid polymer electrolyte (zPU-SPE) that offers high ionic conductivity, strong interaction with electrodes, and excellent mechanical and electrochemical stabilities, making it promising for high-performance all solid-state lithium batteries (ASSLBs). The zPU-SPE exhibits remarkable lithium-ion (Li+) conductivity (3.7 × 10⁻⁴ S cm−1 at 25 °C), enabled by exceptionally high salt loading of up to 90 wt.% (12.6 molar ratio of Li salt to polymer unit) without phase separation. It addresses the limitations of conventional SPEs by combining high ionic conductivity with a Li+ transference number of 0.44, achieved through the incorporation of zwitterionic groups that enhance ion dissociation and transport. The high surface energy (338.4 J m−2) and elasticity ensure excellent adhesion to Li anodes, reducing interfacial resistance and ensuring uniform Li+ flux. When tested in Li||zPU||LiFePO₄ and Li||zPU||S/C cells, the zPU-SPE demonstrated remarkable cycling stability, retaining 76% capacity after 2000 cycles with the LiFePO4 cathode, and achieving 84% capacity retention after 300 cycles with the S/C cathode. Molecular simulations and a range of experimental characterizations confirm the superior structural organization of the zPU matrix, contributing to its outstanding electrochemical performance. The findings strongly suggest that zPU-SPE is a promising candidate for next-generation ASSLBs.

Wang, Kun↗
DOE OSTI2020

Highly Ordered Carbon Coating Prepared with Polyvinylidene Chloride Precursor for High‐Performance Silicon Anodes in Lithium‐Ion Batteries

Abstract A highly ordered carbon structure based on polyvinylidene chloride precursor has been developed to host silicon nanoparticles. The stoichiometric ratio of sacrificial H and Cl elements facilitated full utilization of the carbon content of the precursor that produced robust carbon coatings on silicon nanoparticles with excellent mechanic properties and electrochemical stabilities. The optimal sintering temperature and carbon content have been investigated. When evaluated as the anode of a lithium‐ion battery (LIB), the Si : C 1 : 2 composite sintered at 800 °C (SiC12‐800) provided excellent capacity retention of 85 % at 0.1 C after 50 cycles with an enhanced CE, which reached 99 % only after 10 cycles. The SiC12‐800 electrode maintained a specific capacity of 709.2 mAh/g after 300 cycles at 0.3 C, and delivered a high rate performance of 737.9 mAh/g and 485.6 mAh/g at 5 C and 10 C, respectively. The results indicate that polymer precursors with stoichiometric ratio of sacrificial elements have high potential for generating highly robust carbon coatings for silicon anodes in high energy density LIBs.

Zhou, Shuo↗
DOE OSTI2025

Homogenization of Dendritic Structures and the High-Temperature Strength of the Refractory High-Entropy Alloy MoNbTaVW

MoNbTaVW, a pioneering refractory high-entropy alloy (RHEA), is renowned for its exceptional strength at elevated temperatures. Like most RHEAs, it solidifies into a dendritic microstructure with steep concentration gradients, necessitating heat treatment for equilibration. Steep concentration gradients typically complicate mechanical property analysis and modeling, key challenges for high-throughput alloy discovery. This study examines the effects of high-temperature homogenization (1800 °C for 8 hours) on the microstructure and mechanical properties of MoNbTaVW across temperatures up to 1200 °C. Postmortem microstructural analysis, coupled with chemical, crystallographic, and mechanical assessments, revealed that yield strength was surprisingly insensitive to homogenization, with less than a 3 pct difference between as-cast and heat-treated materials. Nanoindentation confirmed minimal nanohardness changes across the dendritic structure at room temperature. However, homogenization significantly enhanced high-temperature work hardening, producing higher peak compressive strength. Both as-cast and homogenized MoNbTaVW exhibited room-temperature strengths of 1400 MPa, exceeding previously reported values. These findings demonstrate that high-temperature treatment enables microstructural homogenization without compromising strength, a unique behavior among RHEAs. In conclusion, while not universally applicable, this insight highlights the importance of understanding microstructural development in experimental alloys and offers a pathway to design alloys that achieve homogeneous-like properties without heat treatment.

Rietema, C. J. [Lawrence Livermore National Labora↗
DOE OSTI2011

Dose Escalation Improves Cancer-Related Events at 10 Years for Intermediate- and High-Risk Prostate Cancer Patients Treated With Hypofractionated High-Dose-Rate Boost and External Beam Radiotherapy

Purpose: To evaluate the 10-year outcomes of intermediate- and high-risk prostate cancer patients treated with a prospective dose escalation hypofractionated trial of pelvic external beam radiation therapy (P-EBRT) with a high-dose-rate (HDR) brachytherapy boost. Methods and Materials: From 1992 to 2007, 472 patients were treated with a HDR boost at William Beaumont Hospital. They had at least one of the following: a prostate-specific antigen (PSA) level of >10 ng/ml, a Gleason score of {>=}7, or clinical stage {>=}T2b. Patients received 46-Gy P-EBRT and an HDR boost. The HDR dose fractionation was divided into two dose levels. The prostate biologically equivalent dose (BED) low-dose-level group received <268 Gy, and the high-dose group received >268 Gy . Phoenix biochemical failure (BF) definition was used. Results: Median follow-up was 8.2 years (range, 0.4-17 years). The 10-year biochemical failure rate of 43.1% vs. 18.9%, (p < 0.001), the clinical failure rate of 23.4% vs. 7.7%, (p < 0.001), and the distant metastasis of 12.4% vs. 5.7%, (p = 0.028) were all significantly better for the high-dose level group. On Cox multivariate analysis, higher BED levels (p = 0.017; hazard ratio [HR]= 0.586), pretreatment PSA assays (p < 0.001, HR = 1.022), and Gleason scores (p = 0.004) were significant variables for reduced biochemical failure. Higher dose levels (p, 0.002; HR, 0.397) and Gleason scores (p < 0.001) were significant for clinical failure. Grade 3 genitourinary complications were 2% and 3%, respectively, and grade 3 gastrointestinal complication was <0.5%. Conclusions: This prospective trial using P-EBRT with HDR boost and hypofractionated dose escalation demonstrates a strong dose-response relationship for intermediate- and high-risk prostate cancer patients. The improvement at 10 years for locoregional control with higher radiation doses (BED, > 268Gy) has significantly decreased biochemical and clinical failures as well as distant metastasis.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Long-Term Results After High-Dose Radiotherapy and Adjuvant Hormones in Prostate Cancer: How Curable Is High-Risk Disease?

Purpose: To analyze long-term outcome and prognostic factors for high-risk prostate cancer defined by National Comprehensive Cancer Network criteria treated with high-dose radiotherapy and androgen deprivation in a single institution. Methods and Materials: A total of 306 patients treated between 1995 and 2007 in a radiation dose-escalation program fulfilled the National Comprehensive Cancer Network high-risk criteria. Median International Commission on Radiation Units and Measurements radiation dose was 78 Gy (range, 66.0-84.1 Gy). Long-term androgen deprivation (LTAD) was administered in 231 patients, short-term androgen deprivation (STAD) in 59 patients, and no hormones in 16 patients. The Phoenix (nadir plus 2 ng/mL) consensus definition was used for biochemical control. Multivariate analysis was performed to determine the independent prognostic impact of clinical and treatment factors. Median follow-up time was 64 months (range, 24-171 months). Results: The actuarial overall survival at 5 and 10 years was 95.7% and 89.8%, respectively, and the corresponding biochemical disease-free survival (bDFS) was 89.5% and 67.2%, respectively. Fourteen patients (4.6%) developed distant metastasis. Multivariate analysis showed that Gleason score >7 (p = 0.001), pretreatment prostate-specific antigen (PSA) level >20 ng/mL (p = 0.037), higher radiation dose (p = 0.005), and the use of adjuvant LTAD vs. STAD (p = 0.011) were independent prognostic factors affecting bDFS in high-risk disease. The 5-year bDFS for patients treated with LTAD plus radiotherapy dose >78 Gy was 97%. Conclusions: For high-risk patients the present series showed that the use of LTAD in conjunction with higher doses (>78 Gy) of radiotherapy was associated with improved biochemical tumor control. We observed that the presence of Gleason sum >7 and pretreatment PSA level >20 ng/mL in the same patient represents a 6.8 times higher risk of PSA failure. These men could be considered for clinical trials with addition of novel agents.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Redefining High-Risk Prostate Cancer Based on Distant Metastases and Mortality After High-Dose Radiotherapy With Androgen Deprivation Therapy

Purpose: Modern outcomes of high-dose external beam radiotherapy (EBRT) with androgen deprivation therapy (ADT) for high-risk (HR) prostate cancer are not well described. Methods and Materials: We identified 585 patients who met HR criteria by 2010 National Comprehensive Cancer Network guidelines, who were treated with EBRT consisting of {>=}74 Gy from 1996 to 2008 at Cleveland Clinic, of whom 95% received ADT. We analyzed biochemical relapse-free survival (bRFS), distant metastases-free survival (DMFS), and prostate cancer-specific mortality (PCSM). Results: The median EBRT dose was 78 Gy, and median ADT duration was 6 months. At 10 years, the bRFS was 50.2%, the DMFS was 71.6%, and the PCSM was 14.4%. On multivariate analysis, significant predictors of bRFS were biopsy Gleason score (bGS) of 8 to 10, stage T3, and prostate-specific antigen (PSA) concentration; predictors of DMFS were bGS of 8 to 10 and stage T3; the only predictor of PCSM was bGS of 8 to 10. The duration of ADT was not predictive of any endpoint. We identified an unfavorable high-risk (UHR) group of stage T1-T2 tumors consisting of bGS of 8 with PSA of >10 ng/ml or bGS of 9 to 10 with any PSA level; the remaining clinically localized cancers comprised the favorable high-risk (FHR) group. Comparing FHR, UHR, and stage T3 groups, the DMFS rates were 81.4%, 57.8%, and 59.1% (p < 0.0001), and the PCSM rates were 7.5%, 28.4%, and 20.6% at 10 years, respectively (p = 0.006). Conclusion: A bGS of 8 to 10 is the strongest predictor of bRFS, DMFS, and PCSM after high-dose EBRT with ADT. The duration of ADT did not correlate with outcome. Future studies should account for the heterogeneity in HR prostate cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2024

Rheology characterization of ionic liquids under high pressure and high temperature

Ionic liquids (ILs) are liquid salts that exist at or below ambient temperatures and are composed of ion pairs. They offer promising alternatives to toxic, hazardous, highly flammable, and volatile solvents in various applications such as solution preparation, dispersion, gel formation, composites, and polymer melts. ILs possess unique and interesting characteristics, including excellent chemical and thermal stability and low vapor pressures. Understanding the rheological properties of ILs is essential to optimizing IL performance. This paper presents a comparative analysis of the rheological properties of two ionic liquids, Nsingle bondHexylpyridinium tetrafluoroborate (HPyBF4) and Nsingle bondHexylpyridinium bromide (HPyBr), under different shear rates, temperatures, and pressures. Rheological measurements were performed under varying controlled pressure and temperature conditions. The experimental investigation covered a pressure range of 689–12,411 kPa [100–1800 psi] and a temperature range from room temperature up to 522 kelvin (K) [480°F]. The primary objective is to explore and compare the flow behavior and viscoelastic characteristics of HPyBF4 and HPyBr under high-pressure and high-temperature conditions. The experimental data showed that HPyBF4 and HPyBr exhibited shear-thinning behavior, and pressure had an insignificant effect on rheology compared to the temperature effect. Under the same testing conditions, HPyBr showed higher shear stress and viscosity than HPyBF4. This research significantly contributes to the improved understanding of the rheological behavior of these specific ionic liquids and their suitability for diverse industrial and scientific applications, particularly in high-pressure and high-temperature environments.

15 GEOTHERMAL ENERGY↗
DOE OSTI2013

BaZn{sub 2}Si{sub 2}O{sub 7} and the solid solution series BaZn{sub 2−x}Co{sub x}Si{sub 2}O{sub 7} (0<x≤2) as high temperature seals for solid oxide fuel cells studied by high-temperature X-ray diffraction and dilatometry

For sealing of solid oxide fuel cells, glasses from which crystalline phases with high coefficient of thermal expansion (CTE) can be crystallized are required. In this paper, a new solid solution series BaZn{sub 2−x}Co{sub x}Si{sub 2}O{sub 7} (0<x≤2) is introduced which exhibit extremely high CTE. The prepared powders were characterized by X-ray diffraction and high-temperature X-ray diffraction (BaZn{sub 2}Si{sub 2}O{sub 7}). Sintered specimens were characterized by dilatometry. The introduction of Co{sup 2+} does not lead to a change in the space group. All compounds show a transition of a low to a high temperature modification. The attributed temperature increases from 300 °C for BaZn{sub 2}Si{sub 2}O{sub 7} to 850 °C for BaCo{sub 2}Si{sub 2}O{sub 7}. The volume expansion which runs parallel to the phase transition decreases with increasing cobalt concentration. The phase BaZn{sub 2}Si{sub 2}O{sub 7} shows the largest CTE and a steep volume effect during phase transition. For the compound BaZn{sub 0.25}Co{sub 1.75}Si{sub 2}O{sub 7} the CTE is minimum (8.6×10{sup −6} K{sup −1} (50–900 °C)) and increases again until for the compound BaCo{sub 2}Si{sub 2}O{sub 7} a CTE of 16.6×10{sup −6} K{sup −1} (50–900 °C) is reached. In the cobalt rich composition range, the CTEs are in the right range for high temperature fuel cells and can be adjusted by the composition. - Graphical abstract: The composition of the solid solution BaZn{sub 2−x}Co{sub x}Si{sub 2}O{sub 7} strongly affects the thermal expansion. Display Omitted - Highlights: • We examined the thermal expansion of solid solutions BaZn{sub 2−x}Co{sub x}Si{sub 2}O{sub 7} (0<x≤2). • BaZn{sub 2}Si{sub 2}O{sub 7} exhibits the highest thermal expansion due to a phase transition. • Substitution of small amounts of Zn{sup 2+} against Co{sup 2+} lead to decreasing thermal expansion. • The thermal expansions re-increased with further increasing Co{sup 2+} concentrations. • Seals based on these solid solutions should be suitable for solid oxide fuel cells.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗