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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Phase I Trial of Stereotactic Body Radiation Therapy Dose Escalation in Pancreatic Cancer

Stereotactic body radiation therapy (SBRT) has demonstrated encouraging local tumor control rates in the treatment of pancreatic cancer, yet we lack prospective clinical trials evaluating dose-escalation strategies among patients treated with 5-fraction SBRT. This phase 1 dose-escalation trial was conducted to determine the maximum tolerated dose of SBRT in patients with pancreatic cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Competing magnetic interactions and emergent phase diagrams in double perovskite Y 2 Ni x Co 1–x MnO 6

We present a comparative study of double perovskites Y 2 Ni x Co 1–x MnO 6 for x = 1, 0.5, and 0. The polycrystalline samples of Y 2 Ni x Co 1–x MnO 6 with space group P2 1 /n were synthesized via sol-gel technique. X-ray photoelectron spectroscopy (XPS) confirms the presence of majority Ni 2+ /Mn 4+ in Y 2 NiMnO 6 (YNMO) and a mixed valence state Ni 2+/3+ /Co 2+/3+ /Mn 4+/3+ in co-doped Y 2 Ni 0.5 Co 0.5 MnO 6 (YNCMO). The temperature dependent magnetization results suggest homogeneous substitution of Ni ions with Co ions with minimal contribution of 3+ cationic magnetic interactions in YNCMO. The superexchange ferromagnetic (FM) interaction has a major contribution to the magnetism of YNMO. The strength of antiferromagnetic (AFM) coupling resulting from the antiphase boundaries in Y 2 Ni x Co 1–x MnO 6 increases with the increase in the Co concentration. The AC susceptibility (AC-χ) study further validates the presence of higher density of antiphase boundaries, which is reflected by the dynamics of domain walls in YNCMO. The isothermal magnetic entropy change (ΔS M ) as functions of temperature and magnetic field is exploited to assess the stabilization of different magnetic phases. Finally, the findings of ΔS M (T,µ 0 H) lead to the proposed new magnetic phase diagrams for Y 2 Ni x Co 1–x MnO 6 for x = 1 and 0.5, in comparison with the previously established phase diagram of Y 2 CoMnO 6 .

36 MATERIALS SCIENCE↗
DOE OSTI2025

Tetragonal structure and uniaxial magnetic anisotropy in the arc-melted (Ce,Zr) 2 (Fe,M) 17 (M = Mo, W, Co) alloys

The tetragonal ThMn 12 -type structure is stabilized in (Ce 1-x Zr x ) 2 T 16 M (x = 0.2 – 0.3; T = Fe or Fe/Co, M = Mo or W) arc-melted alloys. Approximately 5 at% of Mo or W admixture is sufficient to transform the hexagonal Th 2 Ni 17 -type structure of (Ce 1-x Zr x ) 2 Fe 17 into the tetragonal ThMn 12 -type structure of nearly single-phase (Ce 1-x Zr x ) 2 Fe 16 M and/or (Ce 1-x Zr x ) 2 Fe 15 CoM bulk alloys. X-ray Rietveld refinements reveal that Zr and Mo (W) substitute different sites in the tetragonal crystal structure. Zirconium preferentially replaces Ce, whereas Mo (W) substitutes Fe. At room temperature, the tetragonal phases exhibit strong ferromagnetism and a uniaxial magneto-crystalline anisotropy with anisotropy fields of 15 – 17 kOe. These materials possess room-temperature saturation magnetizations of 95 – 105 emu/g and Curie temperature of 420 – 505 K. At some concentrations, concurrent Zr and Mo (W) site occupancy facilitates 1:12 structure formation in bulk alloys with minimal presence of non-magnetic element in the Fe sublattice, thus securing the highest known magnetic moment per Fe atom (∼ 1.37 µ B ) in this type of materials. The intrinsic magnetic characteristics, as well as the absence of critical rare earths (RE), make these compounds interesting for development as low-cost permanent magnets. In conclusion, small Co additions improve the Curie temperature, especially if combined with W.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Crystal structure and magnetic properties of CeFe 11 M (M = Mo, W)

Tetragonal CeFe 11 Mo (struct. type ThMn 12 , a = 8.529(1) Å, c = 4.766(1) Å, V = 346.68(1) Å 3 ) and novel isostructural CeFe 11 W (a = 8.539(1) Å, c = 4.754(1) Å, V = 346.62(1) Å 3 ) are obtained in bulk, as homogenized single-phase arc-melted alloys. Here, their crystal structures are evaluated by full profile Rietveld analysis of the powder X-ray diffraction patterns which confirm that Ce occupies the 2a atomic site in both cases, whereas atomic disorder is present in the Fe-sublattice, i.e., predominantly on the dumbbell 8i site and minorly on two other sites 8j and 8f. In CeFe 11 Mo the third element, M, is mixed with Fe on the 8i dumbbell site and 8f atomic position, whereas in CeFe 11 W, M is mixed on the 8i and 8j Fe sites. In these bulk CeFe 12-x M x alloys the tetragonal structure persists at lower M content, x < 1 here, in comparison to known similar alloys, with x > 1. Because of the low M content, comparably higher values of mass magnetization and Curie temperature are achieved i.e., CeFe 11 Mo: ϭ s = 104 emu/g (14.7 µ B /f.u.), T c = 420 K and CeFe 11 W: ϭ s = 99 emu/g (16.5 µ B /f.u.), T c = 450 K. Magnetocrystalline anisotropy is uniaxial with anisotropy fields H a ∼ 14.5 and 16.5 kOe, respectively. Based on Curie temperature and magnetic anisotropy enhancements, using tungsten as the stabilizing dopant is more beneficial than molybdenum.

36 MATERIALS SCIENCE↗
DOE OSTI2021

OpenMP application experiences: Porting to accelerated nodes

As recent enhancements to the OpenMP specification become available in its implementations, there is a need to share the results of experimentation in order to better understand the OpenMP implementation’s behavior in practice, to identify pitfalls, and to learn how the implementations can be effectively deployed in scientific codes. We report on experiences gained and practices adopted when using OpenMP to port a variety of ECP applications, mini-apps and libraries based on different computational motifs to accelerator-based leadership-class high-performance supercomputer systems at the United States Department of Energy. Additionally, we identify important challenges and open problems related to the deployment of OpenMP. Through our report of experiences, we find that OpenMP implementations are successful on current supercomputing platforms and that OpenMP is a promising programming model to use for applications to be run on emerging and future platforms with accelerated nodes.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2025

A comparative review on cold sprayed cermet coatings and their applications in high temperature corrosion, oxidation and wear resistance

This review article explores the properties and bonding mechanisms specific to cold sprayed cermet coatings, highlighting its contrast with that of pure metals, and pure ceramics. The general cost structure of cold spraying is compared with other thermal spray techniques and the advantages are highlighted. Several cold sprayed cermet coatings with good corrosion, oxidation and wear resistance behavior in elevated temperatures show convincing potential for applications in power generation industries. The important factors that are attributed to producing highly functional cold sprayed cermet coatings are discussed. A strategic approach involving material, equipment, and application specific optimization of the cold spray process is currently relevant and of utmost importance to meet the coating requirements in several industrial applications.

36 MATERIALS SCIENCE↗
DOE OSTI2026

A bioinspired approach for adaptive solid-solid phase change material coatings with optimized surface features for passive thermal regulation

The necessity to reduce global energy consumption calls for innovative strategies in building thermal management. Passive thermal regulation, particularly through bio-inspired designs, offers a promising avenue by mimicking nature's efficient control of optical properties. This research introduces a novel, climate-responsive coating that integrates optimized bio-inspired surface features with a solid-solid phase change material (SS-PCM) to dynamically manage solar absorptivity without adding additional thickness, enabling both heating and cooling as needed. Drawing on the photonic architectures of the Saharan silver ant and Morpho Didius butterfly, we employed a modeling and multi-objective optimization framework to tailor these surface features. Simulations reveal that surface texture, rather than the intrinsic phase transition of the SS PCM, dominates optical control. Relative to a flat SS PCM coating, optimized isotropic random roughness and broader range features yielded the highest passive heating power increase of about 144 % and 319 % respectively suitable for cold climates. Saharan ant-inspired features enhanced passive cooling for hot climates, achieving a 21.8 % improvement. For moderate climates, Butterfly-wing-inspired surface features provided a balanced enhancement of 19 % for heating and 7 % for cooling. Across all cases, the optimized surface features reduced combined heating and cooling energy demand more effectively than the baseline coating, while preserving material thickness. These findings demonstrate that climate-adaptive, optimized bio-inspired surface features can unlock the full potential of SS PCM coatings, providing a versatile pathway to significant energy savings in buildings and other applications. The methodology establishes a framework for designing next-generation adaptive envelopes that leverage natural photonic principles for high-impact, low-cost thermal regulation.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Vaporization behavior of Ir 4 (CO) 12 and Re 2 (CO) 10 measured by torsion effusion gravimetric method

Metal carbonyls are of great importance in chemical vapor deposition (CVD), composite materials fabrication, and other near-net shape technologies. Carbonyl CVD is used for deposition of high-purity metallic and alloy coatings for which vapor pressure data is essential. In this study, we report vapor pressures of solid Ir 4 (CO) 12 and Re 2 (CO) 10 carbonyls measured by using the Knudsen Cell methodology using a torsion effusion thermogravimetric system. The vapor pressure of the Ir 4 (CO) 12 exhibited incongruent vaporization, as the molecular weight (MW) of the effusing species was determined as 128 g/mol as compared to the theoretical MW of 1105 g/mol. It is proposed that the Ir 4 (CO) 12 (s) partially decomposed (~66%) to Ir 4 (CO) 12 (g), Ir(s), and CO(g). The Re 2 (CO) 10 on the other hand, showed congruent behavior with Re 2 (CO) 10 (s) vaporizing to Re 2 (CO) 10 (g) in the measured temperature range. The raw data for vapor pressures was measured using two sets of Knudsen cells with different orifice sizes, and the equilibrium vapor pressures were calculated using Whitman-Motzfeldt methodology. The equilibrium vapor pressures of these carbonyls, partial pressures of gaseous species in case of decomposition, average molecular weights of the effusing gasses were determined. The vapor pressures and Gibbs energies of vaporization reactions of the two above mentioned carbonyls, as well as comparison of vaporization thermodynamics these two carbonyls with other carbonyls from Group VIB to VIIIB are presented in this work.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Investigations into Plasma-Mediated Decomposition of Organoiodide Species as a Pretreatment for Mitigation of Radioiodine Emissions

A plasma-mediated pretreatment step is proposed to decompose methyl iodide (CH 3 I) for facilitating the capture of the iodine radioisotopes present in off-gas streams from used nuclear fuel reprocessing operations. Simulated CH 3 I gas streams were exposed to dielectric barrier discharge (DBD) plasma in a quartz glass continuous-flow reactor using copper electrodes. The kinetics of decomposition of CH 3 I in nitrogen was investigated by varying the applied voltage, inlet concentration, and residence time. The rate of decomposition was proportional to CH 3 I concentration and increased as the applied potential was increased. This effect was incorporated in the kinetics through the dependence of the rate constant on the applied electric field. Decomposition of CH 3 I was not affected by moisture, and the DBD pretreatment is likely to be similarly effective in an air environment as well; however, the results were confounded by a plasma-mediated reaction between nitrogen and oxygen.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2025

Water-In-Glass: A Self-Supporting Inorganic Aqueous Electrolyte

Aqueous rechargeable sodium-ion batteries (ARNIBs) are emerging as cost-effective and safe candidates for large-scale energy storage applications. However, their advancement has been constrained by the narrow electrochemical stability window (ESW) of conventional aqueous electrolytes (1.23 V). Here, in this study, we present a transformative approach using an inexpensive and rapidly dissolvable inorganic glass material, water glass (W-glass), to significantly enhance the ESW and enable the development of solid-state, self-supporting aqueous film (SSA film) electrolytes. These SSA film electrolytes exhibit an extended ESW of up to 3.5 V and a conductivity of ∼10 –4 S/cm at room temperature. Structural analysis using magic-angle spinning nuclear magnetic resonance (NMR) and solution-state NMR reveals that the dissolution of W-glass in water is driven by the interdependent hydrolysis of P–O–P linkages and Na + –H + ion exchange. This work offers a cost-effective and scalable solution for advancing high-performance ARNIB technology, addressing critical barriers to commercial adoption.

Electrochemical stability window↗
DOE OSTI2024

Interlayer Coupling Controlled Ordering and Phases in Polar Vortex Superlattices

The recent discovery of polar topological structures has opened the door for exciting physics and emergent properties. There is, however, little methodology to engineer stability and ordering in these systems, properties of interest for engineering emergent functionalities. Notably, when the surface area is extended to arbitrary thicknesses, the topological polar texture becomes unstable. Here we show that this instability of the phase is due to electrical coupling between successive layers. We demonstrate that this electrical coupling is indicative of an effective screening length in the dielectric, similar to the conductor–ferroelectric interface. Controlling the electrostatics of the superlattice interfaces, the system can be tuned between a pure topological vortex state and a mixed classical-topological phase. This coupling also enables engineering coherency among the vortices, not only tuning the bulk phase diagram but also enabling the emergence of a 3D lattice of polar textures.

3D ordering↗