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Results for “X-ray identification”

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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

X-ray Diffraction Studies of Single-Crystal Materials for Broad Battery Applications

Single-crystal materials have attracted growing interest in battery research due to their well-defined crystallographic orientation, absence of grain boundaries, and enhanced mechanical and electrochemical stability. This Review provides a comprehensive overview of recent advances in the synthesis, structural evolution, and performance optimization of single-crystal electrodes and solid electrolytes. Particular focus is placed on the application of advanced X-ray diffraction (XRD) techniques, including operando synchrotron diffraction, reciprocal space mapping, and Bragg coherent diffraction imaging, which have enabled in-depth investigations of lattice strain, cation disorder, phase transitions, and defect formation. Representative case studies across Ni-rich layered oxides, spinel-type cathodes, and garnet-based electrolytes are examined to highlight the structural features unique to single crystals. Additionally, the synergistic integration of XRD with machine learning, tomography, and spectroscopy is discussed as a powerful direction for real-time analysis and predictive modeling. Furthermore, these insights provide critical guidance for the rational design of high-performance single-crystal materials in lithium, sodium, and solid-state battery systems.

25 ENERGY STORAGE↗
DOE OSTI2024

Scaling and merging time-resolved pink-beam diffraction with variational inference

Time-resolved x-ray crystallography (TR-X) at synchrotrons and free electron lasers is a promising technique for recording dynamics of molecules at atomic resolution. While experimental methods for TR-X have proliferated and matured, data analysis is often difficult. Extracting small, time-dependent changes in signal is frequently a bottleneck for practitioners. Recent work demonstrated this challenge can be addressed when merging redundant observations by a statistical technique known as variational inference (VI). However, the variational approach to time-resolved data analysis requires identification of successful hyperparameters in order to optimally extract signal. In this case study, we present a successful application of VI to time-resolved changes in an enzyme, DJ-1, upon mixing with a substrate molecule, methylglyoxal. We present a strategy to extract high signal-to-noise changes in electron density from these data. Furthermore, we conduct an ablation study, in which we systematically remove one hyperparameter at a time to demonstrate the impact of each hyperparameter choice on the success of our model. We expect this case study will serve as a practical example for how others may deploy VI in order to analyze their time-resolved diffraction data.

47 OTHER INSTRUMENTATION↗
DOE OSTI2026

Decoding α-MoC 1− x Nanoparticle Formation in Continuous Flow via Machine Learning

Molybdenum carbide nanoparticles (α-MoC 1−x NPs) are promising catalysts that offer noble-metal-like performance at lower cost. We report a mild continuous-flow synthesis of α-MoC 1−x NPs from Mo(CO) 6 , coupled with in-line spectroscopic monitoring and machine learning (ML)-based analysis to quantify precursor conversion and product formation in real time. A multilayer perceptron ML model was found to accurately deconvolute complex, nonlinear spectral patterns, enabling identification of a two-step reaction pathway, involving precursor conversion to an amorphous intermediate followed by intraparticle crystallization to α-MoC 1−x NPs, with the first step being rate limiting. Ex situ small angle X-ray scattering (SAXS) and X-ray diffraction (XRD) validation confirm the predicted concentration profiles and crystallization behavior. This integrated approach showcases how ML can empower insights into NP nucleation and growth, paving the way for self-driving, flow-based platforms for NP synthesis.

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

Machine-Learning-Driven Discovery of Water Splitting BaFe 2 O 4 and Human-in-the-Loop Improvement via Al-Substitution for Increased Thermal Stability

Thermochemical hydrogen (TCH) production offers a promising method for converting thermal energy into hydrogen fuel through heat-driven redox cycles of metal oxides. Here, in this work a defect graph neural network (dGNN) was used to predict oxygen vacancy formation energies ΔH V O combined with Materials Project predictions of oxygen chemical potential stability to screen candidate oxides via high-throughput database analysis. BaFe 2 O 4 was identified as a promising material for experimental validation based on its predicted ΔH V O , oxygen chemical potential stability range, and potential for tunable substitutions to improve thermal properties. Experimental validation using thermogravimetric analysis (TGA), stagnation flow reactor (SFR), X-ray diffraction (XRD), and electron microscopy confirmed positive water-splitting behavior but also revealed limitations in thermal stability under aggressive reduction conditions. To address this, a human-in-the-loop modification strategy was employed introducing Al substitution in BaFe 2–x Al x O 4 ; this modification improves thermal stability, alters the crystal structure and enhances overall performance. These results demonstrate a combined computational and experimental workflow in which machine learning accelerates identification of promising candidates, while targeted experimental design enables optimization of functional performance. This approach advances the development of robust, cost-effective TCH materials and highlights the importance of integrating data-driven discovery with human-guided materials design in paving the way for scalable hydrogen production technologies.

organic↗
NASA NTRS1967

Mechanized X-ray inspection system for large tanks

Mechanized X ray equipment provides nondestructive inspection of structural weldments at various positions on very large tanks. It mechanizes the placement of the film, automates the identification process, adheres to safety requirements, and eliminates all the usual time-consuming manual operations in industrial radiography.

Occhipinti, G. C.↗
NASA NTRS1972

On the optical identification of Centaurus X-3.

It is suggested that the previously photographed emission-line star WRA 795 is the optical counterpart of Cen X-3, the X-ray pulsar which is a member of an occulting binary system. The star falls in the X-ray error box, which measures only 0.01 square degrees, and shows strong emission variability on a timescale of days, similar to HDE 226868, the suggested Cyg X-1 counterpart.

Margon, B.↗
NASA NTRS1971

X-ray astronomy from sounding rockets at MIT

The research in the program for designing and fabricating payloads for sounding rockets for use in X-ray astronomy is reported. Published papers concerning six Aerobee flights are presented. The results include: (1) the establishment of the radio galaxy M87 as an X-ray source; (2) the studies of the pulsar NPO532, including its X-ray pulse shape, the determination of the synchronism of the optical and X-ray pulses and the codiscovery of its existence as an X-ray pulsar; (3) the determination of many X-ray source positions, and (4) the precise position of Cyg X-1 which led directly to the identification of a ninth magnitude BO supergiant.

Source record↗
NASA NTRS1973

Ultraminiature X-ray fluorescence spectrometer for in-situ geochemical analysis on Mars.

A spectrometer based upon the X-ray fluorescence method of elemental analysis has been developed in an ultraminiature, rugged form suitable for a spacecraft mission to Mars. The instrument employs two radioisotope sources (Fe-55 and Cd-109) which irradiate adjacent areas on a regolith sample. Fluorescent X rays emitted by the sample are detected by four thin-window proportional counters. Using pulse-height discrimination, the energy spectra are determined. Virtually all elements above sodium in the periodic table are detected if present at sufficient levels. Minimum detection limits range from 30 ppm to 2% depending upon the element and the matrix. For most elements, they are below 0.5%. Accuracies also depend upon the matrix, but are generally better than plus or minus 0.5% for all elements of atomic number greater than 14. Elements below sodium are also detected, but as a single group. Ambiguities of identification of the elements producing the observed spectra are minimal.

Clark, B. C.↗
NASA NTRS1975

Centaurus X-3 - New low- and medium-energy X-ray observations

Low- and medium-energy X-ray observations of Cen X-3 during two pointed sounding-rocket experiments are discussed. The lack of low-energy emission from Cen X-3 is consistent with the identification of Krzeminski's star as the optical counterpart of Cen X-3 and normal reddening, in contrast to an earlier measurement by Bleeker et al (1973).

Long, K.↗
NASA NTRS1976

The Identification of Scientific Programs to Utilize the Space Environment

A program to identify and develop ideas for scientific experimentation on the long duration exposure facility (LDEF) was completed. Four research proposals were developed: (1) Ultra pure germanium gamma ray radiation detectors in the space environment, intended to develop and demonstrate an X-ray and gamma-ray spectroscopy system incorporating a temperature cyclable high-purity germanium detector and diode heat pipe cryogenic system for cooling, (2) growth, morphogenesis and metabolism of plant embryos in the zero-gravity environment, to investigate if the space environment induces mutations in the embryogenic cells so that mutants of commercial significance with desirable attributes may be obtained, (3) effect of zero gravity on the growth and pathogenicity of selected zoopathic fungi. It is possible that new kinds of treatment for candidiasis, and tichophytosis could eventuate from the results of the proposed studies, and (4) importance of gravity to survival strategies of small animals. Gravitational effects may be direct or mediate the selection of genetic variants that are preadapted to weightlessness.

Kulacki, F. A.↗
NASA NTRS1978

Gamma-ray lines from neutron stars as probes of fundamental physics

The detection of gamma-ray lines produced at the surface of neutron stars will serve to test both the strong and gravitational interactions under conditions unavailable in terrestrial laboratories. Observation of a single redshifted gamma-ray line, combined with an estimate of the mass of the star will serve as a strong constraint on allowable equations of state of matter at supernuclear densities. Detection of two redshifted lines arising from different physical processes at the neutron star surface can provide a test of the strong principle of equivalence. Expected fluxes of nuclear gamma-ray lines from accreting neutron stars were calculated, including threshold, radiative transfer and redshift effects. The most promising probes of neutron star structure are the deuterium formation line and the positron annihilation line. Detection of sharp redshifted gamma-ray lines from X-ray sources such as Cyg X-1 would argue strongly in favor of a neutron star rather than black hole identification for the object.

Brecher, K.↗
NASA NTRS1978

X-ray observations of BL Lac objects

The BL Lac objects MK501 and MK421 were observed with OSO-8 and HEAO-1 X-ray detectors in the 2-60 keV band. Their spectra are similar with best fitting power laws having energy index -.4 alpha 4. A soft X-ray excess is indicated in their spectra. There was no detectable X-ray absorption with implied column densities N sub H 1.5 x 10 to the 22d power at sq cm. MK421 was a factor 6 weaker in November 1977 than in May 1977. An identification of PKS0548-322 with a new source H0548,-32 is suggested.

Mushotzky, R. F.↗
NASA NTRS1978

X-ray observations of BL Lacertae objects

Results are reported for OSO 8 and HEAO 1 X-ray observations of the BL Lac objects Mrk 421, Mrk 501, and PKS 0548-322 over the energy range from 2 to 60 keV. It is found that the X-ray spectra of Mrk 421 and 501 are similar, exhibit statistically significant soft X-ray excesses, lack low-energy absorption, and are best fitted by power laws over the 2-30-keV range with respective photon indices of approximately 0.91 and 1.2 and respective hydrogen column densities of less than 8 x 10 to the 21st per sq cm and no more than 1.8 x 10 to the 22nd per sq cm. It is noted that the spectral index for both sources is identical, within errors, to the HF radio spectral index and that Mrk 421 experienced a factor of 6 decrease in the 2-10-keV band over a six-month period. A tentative identification of PKS 0548-322 with the source H0548-32 is suggested.

Mushotzky, R. F.↗