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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS2000

Sensing Water Vapon via Spacecraft Radio Occultation Observations

The radio occultation technique has been used to characterize planetary atmospheres since the 1960's spanning atmospheric pressures from 16 microbars to several bars. In 1988, the use of GPS signals to make occultation observations of Earth's atmosphere was realized by Tom Yunck and Gunnar Lindal at JPL. In the GPS to low-Earth-orbiter limb- viewing occultation geometry, Fresnel diffraction yield a unique combination of high vertical resolution of 100 m to 1 km at long wavelengths (approx. 20 cm) insensitive to particulate scattering which allows routine limb sounding from the lower mesosphere through the troposphere. A single orbiting GPS/GLONASS receiver can observe - 1000 to 1400 daily occultations providing as many daily, high vertical resolution soundings as the present global radiosonde network, but with far more evenly distributed, global coverage. The occultations yield profiles of refractivity as a function of height. In the cold, dry conditions of the upper troposphere and above (T less than 240 K), profiles of density, pressure (geopotential), and temperature can be derived. Given additional temperature information, water vapor can be derived in the midddle and lower troposphere with a unique combination of vertical resolution, global distribution and insensitivity to clouds and precipitation to an accuracy of approx. 0.2 g/kg. At low latitudes, moisture profiles will be accurate to 1-5% within the convective boundary layer and better than 20% below 6 to 7 km. Accuracies of climatological averages should be approx. 0. 1 g/kg limited by the biases in the temperature estimates. To use refractivity to constrain water vapor, knowledge of temperature is required. The simplest approach is to use the temperature field from an analysis such as the 6 hour ECMWF global analysis interpolated to the locations of each occultation. A better approach is to combine the temperature and moisture fields from such an analysis with the occultation refractivity in a weighting scheme based on the errors in each data field. A ID variational combinational approach has been developed at the UKMO. We win present results from both approaches from GPS/MET data taken in June and July 1995 and compare them with the ECMWF global 6 hour moisture analyses which are derived largely from TOVS and radiosonde data. Overall, the atmosphere below the 500 mb level appears somewhat drier in general than the ECNIWF humidity field. A 2-D (latitude vs. height) climatological snapshot derived from a 2-week span of GPS/MET data will be compared to the humidity climatology of Peixoto and Oort derived from radiosonde data from 1963-1973. Differences between the GPS results and Peixoto and Oort may be the signature of a climate trend over the past 30 years.

Kursinski, E. Robert↗
DOE OSTI2023

Revealing the relationship between liquid fragility and medium-range order in silicate glasses

Despite decades of studies, the nature of the glass transition remains elusive. In particular, the sharpness of the dynamical arrest of a melt at the glass transition is captured by its fragility. Here, we reveal that fragility is governed by the medium-range order structure. Based on neutron-diffraction data for a series of aluminosilicate glasses, we propose a measurable structural parameter that features a strong inverse correlation with fragility, namely, the average medium-range distance (MRD). We use in-situ high-temperature neutron-scattering data to discuss the physical origin of this correlation. We argue that glasses exhibiting low MRD values present an excess of small network rings. Such rings are unstable and deform more readily with changes in temperature, which tends to increase fragility. These results reveal that the sharpness of the dynamical arrest experienced by a silicate glass at the glass transition is surprisingly encoded into the stability of rings in its network.

36 MATERIALS SCIENCE↗
NASA NTRS2006

NASA Tech Briefs, December 2006

Topic include: Inferring Gear Damage from Oil-Debris and Vibration Data; Forecasting of Storm-Surge Floods Using ADCIRC and Optimized DEMs; User Interactive Software for Analysis of Human Physiological Data; Representation of Serendipitous Scientific Data; Automatic Locking of Laser Frequency to an Absorption Peak; Self-Passivating Lithium/Solid Electrolyte/Iodine Cells; Four-Quadrant Analog Multipliers Using G4-FETs; Noise Source for Calibrating a Microwave Polarimeter; Hybrid Deployable Foam Antennas and Reflectors; Coating MCPs with AlN and GaN; Domed, 40-cm-Diameter Ion Optics for an Ion Thruster; Gesture-Controlled Interfaces for Self-Service Machines; Dynamically Alterable Arrays of Polymorphic Data Types; Identifying Trends in Deep Space Network Monitor Data; Predicting Lifetime of a Thermomechanically Loaded Component; Partial Automation of Requirements Tracing; Automated Synthesis of Architecture of Avionic Systems; SSRL Emergency Response Shore Tool; Wholly Aromatic Ether-Imides as n-Type Semiconductors; Carbon-Nanotube-Carpet Heat-Transfer Pads; Pulse-Flow Microencapsulation System; Automated Low-Gravitation Facility Would Make Optical Fibers; Alignment Cube with One Diffractive Face; Graphite Composite Booms with Integral Hinges; Tool for Sampling Permafrost on a Remote Planet; and Special Semaphore Scheme for UHF Spacecraft Communications.

Source record↗
DOE OSTI2026

Multi-scale structural analysis of swift heavy ion-irradiated ZrO 2 and HfO 2

The radiation-induced monoclinic-to-tetragonal phase transition in ZrO 2 and HfO 2 has been the subject of many investigations, but the transformation pathways and underlying structural mechanisms are still not well understood. In this study, microcrystalline powder samples of ZrO 2 and HfO 2 were irradiated with 946 MeV and 1470 MeV Au ions to a wide fluence range up to 3 × 10 13 ions/cm 2 . To characterize beam-induced structural modifications across all spatial length scales, complementary experimental techniques such as synchrotron X-ray diffraction and spallation neutron total scattering were used. The phase evolution of the tetragonal polymorph with increasing ion fluence is accurately described by a heterogeneous track-overlap model that incorporates both direct- and double-impact processes. These damage accumulation processes are an expression of a core-shell ion track morphology that depends on irradiation conditions and target material. Neutron pair distribution function analysis revealed that ion-beam-induced tetragonal ZrO 2 is merely a configurational average of short-range orthorhombic (Pbcn) domains stabilized by a dense network of domain walls. Furthermore, this knowledge is critical for a better understanding of how crystalline-to-crystalline phase transformations proceed at the atomic scale under extreme conditions.

Monoclinic-to-tetragonal phase transformation↗
DOE OSTI2025

Dome-like pressure-temperature phase diagram of the cooperative Jahn–Teller distortion in NaNiO 2

NaNiO 2 is a Ni 3+ -containing layered material consisting of alternating triangular networks of Ni and Na cations, separated by octahedrally-coordinated O anions. At ambient pressure, it features a collinear Jahn–Teller distortion below $T^{JT}_{onset} ≈ 480$ K, which disappears in a first-order transition on heating to $T^{JT}_{onset} ≈ 500$ K, corresponding to the increase in symmetry from monoclinic to rhombohedral. It was previously studied by variable-pressure neutron diffraction (Nagle-Cocco et al 2022 ACS Inorg. Chem. 61 4312) and found to exhibit an increasing $T^{JT}_{onset}$ with pressure up to ∼5 GPa. In this work, powdered NaNiO 2 was studied via variable-pressure synchrotron x-ray diffraction up to pressures of ∼67 GPa at 294 K and 403 K. Suppression of the collinear Jahn–Teller ordering is observed via the emergence of a high-symmetry rhombohedral phase, with the onset pressure occurring at ∼18 GPa at both studied temperatures. Further, a discontinuous decrease in unit cell volume is observed on transitioning from the monoclinic to the rhombohedral phase. These results taken together suggest that in the vicinity of the transition, application of pressure causes the Jahn–Teller transition temperature, $T^{JT}_{onset}$, to decrease rapidly. We conclude that the pressure-temperature phase diagram of the cooperative Jahn–Teller distortion in NaNiO 2 is dome-like.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1992

Reconfigurable optical interconnection network for multimode optical fiber sensor arrays

A single-source, single-detector architecture has been developed to implement a reconfigurable optical interconnection network multimode optical fiber sensor arrays. The network was realized by integrating LiNbO3 electrooptic (EO) gratings working at the Raman Na regime and a massive fan-out waveguide hologram (WH) working at the Bragg regime onto a multimode glass waveguide. The glass waveguide utilized the whole substrate as a guiding medium. A 1-to-59 massive waveguide fan-out was demonstrated using a WH operating at 514 nm. Measured diffraction efficiency of 59 percent was experimentally confirmed. Reconfigurability of the interconnection was carried out by generating an EO grating through an externally applied electric field. Unlike conventional single-mode integrated optical devices, the guided mode demonstrated has an azimuthal symmetry in mode profile which is the same as that of a fiber mode.

Chen, R. T.↗
DOE OSTI2022

Structure of water-in-salt and water-in-bisalt electrolytes

We report a systematic diffraction study of two “water-in-salt” electrolytes and a “water-in-bisalt” electrolyte combining high-energy X-ray diffraction (HEXRD) with polarized and unpolarized neutron diffraction (ND) on both H 2 O and D 2 O solutions. The measurements provide three independent combinations of correlations between the different pairs of atom types that reveal the short- and intermediate-range order in considerable detail. The ND interference functions show pronounced peaks around a scattering vector Q ~ 0.5 Å -1 that change dramatically with composition, indicating significant rearrangements of the water network on a length scale around 12 Å. The experimental results are compared with two sets of Molecular Dynamics (MD) simulations, one including polarization effects and the other based on a non-polarizable force field. The two simulations reproduce the general shapes of the experimental structure factors and their changes with concentration, but differ in many detailed respects, suggesting ways in which their force fields might be modified to better represent the actual systems.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Data-driven modeling and control of an X-ray bimorph adaptive mirror

Adaptive X-ray mirrors are being adopted on high-coherent-flux synchrotron and X-ray free-electron laser beamlines where dynamic phase control and aberration compensation are necessary to preserve wavefront quality from source to sample, yet challenging to achieve. Additional difficulties arise from the inability to continuously probe the wavefront in this context, which demands methods of control that require little to no feedback. In this work, a data-driven approach to the control of adaptive X-ray optics with piezo-bimorph actuators is demonstrated. This approach approximates the non-linear system dynamics with a discrete-time model using random mirror shapes and interferometric measurements as training data. For mirrors of this type, prior states and voltage inputs affect the shape-change trajectory, and therefore must be included in the model. Without the need for assumed physical models of the mirror's behavior, the generality of the neural network structure accommodates drift, creep and hysteresis, and enables a control algorithm that achieves shape control and stability below 2 nm RMS. Using a prototype mirror and ex situ metrology, it is shown that the accuracy of our trained model enables open-loop shape control across a diverse set of states and that the control algorithm achieves shape error magnitudes that fall within diffraction-limited performance.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Electrical design of the flexible imaging diffraction diagnostic for laser experiments (FIDDLE) at the National Ignition Facility (NIF)—Requirements, design, and performance

The Flexible Imaging Diffraction Diagnostic for Laser Experiments (FIDDLE) is a newly developed diagnostic for imaging time resolved diffraction in experiments at the National Ignition Facility (NIF). It builds on the successes of its predecessor, the Gated Diffraction Development Diagnostic (G3D). The FIDDLE was designed to support eight Daedalus version 2 sensors (six more hCMOS sensors than any other hCMOS-based diagnostic in NIF to date) and an integrated streak camera. We will review the electrical requirements, design, and performance of the electrical subsystems that were created to support this large number of cameras in the FIDDLE. The analysis of the data that the FIDDLE is intended to collect relies heavily on the accurate and well-understood timing of each sensor. We report camera-to-camera timing jitter of less than 100 ps rms and sensor integration times of 2.2 ns FWHM in 2-2 timing mode. Additionally, diffraction experiments on the NIF produce electric fields (EMI) on the order of 1 kV/m, which have been observed to negatively impact the performance of some electrical components of the FIDDLE. We report on the results of testing hCMOS camera electronics in a similar EMI environment generated in an offline lab. In addition, we also summarize the use of a novel approach to using a vector network analyzer as an EMI leak detector to understand and reduce the negative impacts of EMI on the FIDDLE.

47 OTHER INSTRUMENTATION↗
NASA NTRS2011

Polished Panel Optical Receiver for Simultaneous RF/Optical Telemetry with Large DSN Antennas

The polished panel optical receiver concept described here makes use of aluminum panels on the main reflector of the Deep Space Network's (DSN's) 34-meter antennas at optical wavelengths by polishing and coating their surface to efficiently reflect near-infrared wavelengths in the 1,064 1,550-nanometer range. Achievable surface smoothness is not a limiting factor for aluminum panels, and initial field experiments indicate that the surface quality of microwave aluminum panels is sufficient to concentrate the light into small, but not diffraction-limited, spots at their primary focus. Preliminary analysis of data from high-quality microwave panels has shown that the light can be concentrated into 200 400 microradian cones, resulting in spot diameters of 2-4 mm at the 10-meter primary focus F(0) shown in the figure, or 2-4 cm spots at F(1) after magnification by the subreflector, which results in an effective focal length of about 100 meters. Three distinct implementation options are possible, with theoretically identical tracking and communications performance: Option 1: The communications assembly could be placed directly behind the subreflector at F(0), but this placement would require replacing the existing all-aluminum subreflector with a new design that transmits optical wavelengths but reflects RF, thus transmitting the optical signal to the primary focus of the parabolic polished aluminum panels at F(0), as shown in the figure. Option 2: Alternately, the optical communications assembly could be located near the first available focal-spot F(1) following reflection by the subreflector (which would have to be polished), next to the input to the beam waveguide on the main reflector as shown in the figure. Option 3: Finally, the optical communications assembly could be placed inside the pedestal room, and separated from the RF signal after the ellipsoid and before the signal reached the microwave receiver via an RF/optical dichroic near F(3).

Vilnrotter, Victor A.↗
DOE OSTI2022

The mechanisms of catalysis and ligand binding for the SARS-CoV-2 NSP3 macrodomain from neutron and x-ray diffraction at room temperature

The nonstructural protein 3 (NSP3) macrodomain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Mac1) removes adenosine diphosphate (ADP) ribosylation posttranslational modifications, playing a key role in the immune evasion capabilities of the virus responsible for the coronavirus disease 2019 pandemic. Here, we determined neutron and x-ray crystal structures of the SARS-CoV-2 NSP3 macrodomain using multiple crystal forms, temperatures, and pHs, across the apo and ADP-ribose–bound states. We characterize extensive solvation in the Mac1 active site and visualize how water networks reorganize upon binding of ADP-ribose and non-native ligands, inspiring strategies for displacing waters to increase the potency of Mac1 inhibitors. Determining the precise orientations of active site water molecules and the protonation states of key catalytic site residues by neutron crystallography suggests a catalytic mechanism for coronavirus macrodomains distinct from the substrate-assisted mechanism proposed for human MacroD2. These data provoke a reevaluation of macrodomain catalytic mechanisms and will guide the optimization of Mac1 inhibitors.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

High‐pressure Synthesis of Cobalt Polynitrides: Unveiling Intriguing Crystal Structures and Nitridation Behavior

Abstract In this study, we conduct extensive high‐pressure experiments to investigate phase stability in the cobalt‐nitrogen system. Through a combination of synthesis in a laser‐heated diamond anvil cell, first‐principles calculations, Raman spectroscopy, and single‐crystal X‐ray diffraction, we establish the stability fields of known high‐pressure phases, hexagonal NiAs‐type CoN, and marcasite‐type CoN 2 within the pressure range of 50–90 GPa. We synthesize and characterize previously unknown nitrides, Co 3 N 2 ,Pnma‐CoN and two polynitrides, CoN 3 and CoN 5 , within the pressure range of 90–120 GPa. Both polynitrides exhibit novel types of polymeric nitrogen chains and networks. CoN 3 feature branched‐type nitrogen trimers (N 3 ) and CoN 5 show π‐bonded nitrogen chain. As the nitrogen content in the cobalt nitride increases, the CoN 6 polyhedral frameworks transit from face‐sharing (in CoN) to edge‐sharing (in CoN 2 and CoN 3 ), and finally to isolated (in CoN 5 ). Our study provides insights into the intricate interplay between structure evolution, bonding arrangements, and high‐pressure synthesis in polynitrides, expanding the knowledge for the development of advanced energy materials

Chemistry↗
DOE OSTI2026

BMINN: Learning chemical potentials and parameters from voltage data for multi-phase battery modeling

Free-energy landscapes and chemical potentials govern the dynamics of phase transitions, transport, and stability in functional materials, yet they remain experimentally inaccessible under realistic operating conditions. Here we introduce a Bayesian model-integrated neural network (BMINN) that embeds physics-based formulations of non-autonomous partial differential-algebraic equations into probabilistic learning. This approach reconstructs hidden thermodynamics directly from macroscopic current-voltage data, providing quantitative access to metastable states, staging transitions, and energy barriers without synchrotron probes. Demonstrated on lithium-graphite electrodes, BMINN recovers full Gibbs free-energy landscapes with fidelity validated against operando X-ray diffraction. The framework generalizes across dynamical regimes, enabling accurate voltage prediction, internal state estimation, and inference of governing parameters. Beyond batteries, BMINN exemplifies a broadly applicable strategy for learning missing physics in multiphase, non-equilibrium systems, offering a new pathway to uncover hidden thermodynamic functions across condensed matter and materials physics.

25 ENERGY STORAGE↗
DOE OSTI2020

Modulation of crystal growth and structure within cerium-based metal–organic frameworks

The intriguing catalytic properties of cerium-based materials have motivated the development of Ce-based metal–organic frameworks (MOFs). However, the controlled crystallization of Ce MOFs remains nascent due to complications with the high reduction potential of Ce 4+ species. Modulators offer a route in other well-studied coordination networks to slow down crystallization processes to allow for corrective, uniform crystal growth. Herein, we report an investigation of modulator identity and concentration on the synthesis of a Ce-UiO-type MOF with 2,6-naphthalenedicarboxylic acid (NDC) as a linker. At low concentrations using both benzoic acid and trifluoroacetic acid, we observed a mononuclear Ce 3+ MOF (NU-350) through single-crystal X-ray diffraction studies. Higher modulator concentrations yielded pure-phase Ce-UiO-NDC, with uniform particle sizes observed with utilizing benzoic acid as a modulator. Moreover, we demonstrated the transferability of this synthesis through the pure-phase synthesis of Ce-UiO-66 with benzoic acid as a modulator. High-resolution transmission electron microscopy showed a single crystalline domain within Ce-UiO-NDC.

36 MATERIALS SCIENCE↗
DOE OSTI2021

PhaseGAN: a deep-learning phase-retrieval approach for unpaired datasets

Phase retrieval approaches based on deep learning (DL) provide a framework to obtain phase information from an intensity hologram or diffraction pattern in a robust manner and in real-time. However, current DL architectures applied to the phase problem rely on i) paired datasets, i. e., they arc only applicable when a satisfactory solution of the phase problem has been found, and ii) the fact that most of them ignore the physics of the imaging process. Here, we present PhaseGAN, a new DL approach based on Generative Adversarial Networks, which allows the use of unpaired datasets and includes the physics of image formation. The performance of our approach is enhanced by including the image formation physics and a novel Fourier loss function, providing phase reconstructions when conventional phase retrieval algorithms fail, such as ultra-fast experiments. Thus, PhaseGAN offers the opportunity to address the phase problem in real-time when no phase reconstructions but good simulations or data from other experiments are available.

47 OTHER INSTRUMENTATION↗
DOE OSTI2024

Effects of Al Substitution for Fe in Na₅FeSi₄O₁₂ (5.1.8) Glasses: Structure and Crystallization

In this study, the effects of substituting Al for Fe in 5Na2O∙(Al2O3)x∙(Fe2O3)1-x∙8SiO2 glass, x=0 to 1, and Na5AlxFe1-xSi4O12 (5.1.8) crystal, were investigated using thermal analysis, Fe K-edge X-ray absorption, X-ray diffraction, Raman spectroscopy, and Electron Probe Microanalysis. In both glass and crystallized glass, nearly all the Fe was tetrahedrally coordinated Fe3+, as expected from the high concentration of Na2O. The substitution of Al for Fe in the glasses caused the glass transition temperature to increase as polymerization increased, as evidenced by Raman, likely due to both field strength differences of Al vs Fe and a small amount of Fe2+ network modifier present with Fe. After heat treatment at 700 °C for 24 hours, the glasses had crystallized, forming Na2SiO3 and NaAlSiO4 in compositions with high Al concentrations and the 5.1.8 crystal in compositions with high Fe concentrations. Through electron microprobe, it was determined that <0.04 formula unit Al incorporated into the 5.1.8 crystal, i.e. Na5Fe0.96Al0.04Si4O12. The 5.1.8 crystal only formed when Fe concentration was higher than Al in the starting glass.

Antonio, Raine (ORCID:0009000634297975)↗
NASA NTRS1987

DSS 43 antenna gain analysis for Voyager Uranus encounter: 8.45-GHz radio science data correction

A malfunction of the Deep Space Network (DSN) 64-meter antenna in Australia forced the antenna to operate with a mispositioned subreflector during the Voyager Uranus encounter period (January 24, 1986). Because of changing main reflector shape and quadripod position as a function of elevation angle, the antenna gain and pointing were not as expected, and the 8.45 GHz received signal level changed during the pass. The study described here used the Geometrical Theory of Diffraction (GTD) analysis to determine actual antenna gain and pointing during that period in an attempt to reconstruct the radio science data. It is found that the 1.4 dB of signal variation can be accounted for by antenna geometry changes and pointing error. Suggested modifications to the values measured during the pass are presented. Additionally, an extremely useful tool for the analysis of gravity deformed reflectors was developed for use in future antenna design and analysis projects.

Slobin, S. D.↗