Search NASA⌕ Search

SEARCH · Search NASA

Results for “In situ visualization”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

In-Situ Visualization of Long-Range Defect Interactions at the Edge of Melting

Connecting a bulk material’s microscopic defects to its macroscopic properties is an age-old problem in materials science. Long-range interactions between dislocations (line defects) are known to play a key role in how materials deform or melt, but we lack the tools to connect these dynamics to the macroscopic properties. We introduce time-resolved dark-field X-ray microscopy to directly visualize how dislocations move and interact over hundreds of micrometers, deep inside bulk aluminum. With real-time movies, we reveal the thermally activated motion and interactions of dislocations that comprise a boundary, and show how weakened binding forces inhomogeneously destabilize the structure at 99% of the melting temperature. Connecting dynamics of the microstructure to its stability, we provide important opportunities to guide and validate multiscale models that are yet untested.

36 MATERIALS SCIENCE↗
DOE OSTI2020

InSituNet: Deep Image Synthesis for Parameter Space Exploration of Ensemble Simulations

We propose InSituNet, a deep learning based surrogate model to support parameter space exploration for ensemble simulations that are visualized in situ. In situ visualization, generating visualizations at simulation time, is becoming prevalent in handling large-scale simulations because of the I/O and storage constraints. However, in situ visualization approaches limit the flexibility of post-hoc exploration because the raw simulation data are no longer available. Although multiple image-based approaches have been proposed to mitigate this limitation, those approaches lack the ability to explore the simulation parameters. Our approach allows flexible exploration of parameter space for large-scale ensemble simulations by taking advantage of the recent advances in deep learning. Specifically, we design InSituNet as a convolutional regression model to learn the mapping from the simulation and visualization parameters to the visualization results. With the trained model, users can generate new images for different simulation parameters under various visualization settings, which enables in-depth analysis of the underlying ensemble simulations. We demonstrate the effectiveness of InSituNet in combustion, cosmology, and ocean simulations through quantitative and qualitative evaluations.

deep learning↗
DOE OSTI2021

Catalyst Revised: Rethinking the ParaView in Situ Analysis and Visualization API

As in situ analysis goes mainstream, ease of development, deployment, and maintenance becomes essential, perhaps more so than raw capabilities. In this paper, we present the design and implementation of Catalyst, an API for in situ analysis using ParaView, which we refactored with these objectives in mind. Furthermore, our implementation combines design ideas from in situ frameworks and HPC tools like Ascent and MPICH.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2025

Neutron-Friendly Li-Ion Battery Coin Cell for In Situ 3D Visualization of Li Plating

Advanced battery characterization using in situ/operando neutron imaging is critical for uncovering degradation modes such as lithium (Li) plating in Li-ion batteries (LIBs). However, conventional LIBs hinder operando neutron radiography (NR) and in situ neutron micro-computed tomography (N-μCT) for visualizing Li plating near the graphite-separator interface due to strong attenuation from hydrogen-rich components like PP–PE–PP separators, electrolyte, and Fe-based spacers. In this work, we designed and tested a neutron-friendly battery (NFB) optimized for in situ Li detection during extreme fast charging (XFC). Guided by neutron attenuation cross-sections and material transmission, the NFB enables clear visualization at the graphite–separator interface, which is typically opaque in standard LIBs. Electrochemical tests show the NFB exhibits voltage/current responses like standard cells for up to 50 XFC cycles. However, its lower reversibility and capacity are likely due to Cu-coated Al spacer degradation from delamination or corrosion. We propose titanium spacers as a more stable alternative, albeit requiring custom machining. Using this optimized cell, we achieved simultaneous neutron tomography of multiple cells, capturing in situ 3D images of dead Li accumulation, particularly near graphite edges. These heterogeneous deposits and disconnected Li clusters suggest localized current density hotspots during XFC.

25 ENERGY STORAGE↗
DOE OSTI2021

In-situ 4D visualization and analysis of temperature-driven creep in an oil shale propped fracture

Here, the proppant embedment due to creep in shales is a known issue affecting the useable lifetime of wells in unconventional oil and gas recovery. One of the factors influencing creep is the presence of organics, whose properties can be very sensitive to temperature. In this work we investigated for the first time the role of temperature-induced creep increase in proppant embedment in an organics-rich Green River oil shale sample via in-situ synchrotron X-ray micro-computed tomography. We observed that temperatures as low as 75 °C already induce fast creep, with a fracture aperture closing rate of 13 μm/h and a loss of fracture conductivity rate of 8.7%/h, due only to proppant embedment, in the measured interval at the first heating stage. Local displacement data analysis provided evidence for markedly plastic deformation around the proppant-shale contacts, in contrast with the brittle proppant embedment observed on more cemented and less organics-rich shales at room temperature. The results highlight how the problem of temperature-dependent mechanical behavior might be more important than previously thought, in shales with a high content in organics, and that in-situ micro-imaging techniques can play a key role in understanding the underlying mechanisms, contributing to solve creep-related problems associated with hydraulic fracturing in complex scenarios.

02 PETROLEUM↗
DOE OSTI2026

In-situ observation of calcium chloride hexahydrate phase separation via neutron imaging

Inorganic salt hydrate offers a low-cost thermal energy storage solution with high energy density, but phase separation during thermal cycling poses a significant challenge, leading to irreversible performance degradation. In this research, neutron radiography was used to investigate phase separation in calcium chloride hexahydrate (CaCl₂·6H₂O, CCH) during thermal cycling to track its gradual accumulation into calcium chloride tetrahydrate (CaCl₂·4H₂O, CC4). Through in-situ visualization, phase separation and CC4 sedimentation were observed to occur during the cooling phase between 301.40 K and 304.80 K. CC4 accumulated linearly to 7.99 wt% after 10 thermal cycles. Crystallization and multi-cycle conversion models were developed to validate neutron imaging results of CC4 formation. The predicted CC4 content after 10 thermal cycles closely aligned with experimental observations. Neutron imaging offers a novel approach to investigate salt hydrate phase change materials (PCMs). It enables in-situ visualization of sub-hydrate (CC4) formation from original hydrate (CCH) in metastable phase change range (between 301.40 ± 0.66 K and 304.80 ± 0.60 K). Thereby, it provides a new insight of understanding the basis of phase separation mechanism and paves the way for future research of improving PCM thermal cycling performance.

Li, Yucen [The University of Tennessee, Knoxville]↗
DOE OSTI2024

The ECP ALPINE project: In situ and post hoc visualization infrastructure and analysis capabilities for exascale

A significant challenge on an exascale computer is the speed at which we compute results exceeds by many orders of magnitude the speed at which we save these results. Therefore the Exascale Computing Project (ECP) ALPINE project focuses on providing exascale-ready visualization solutions including in situ processing. In situ visualization and analysis runs as the simulation is run, on simulations results are they are generated avoiding the need to save entire simulations to storage for later analysis. The ALPINE project made post hoc visualization tools, ParaView and VisIt, exascale ready and developed in situ algorithms and infrastructures. The suite of ALPINE algorithms developed under ECP includes novel approaches to enable automated data analysis and visualization to focus on the most important aspects of the simulation. Many of the algorithms also provide data reduction benefits to meet the I/O challenges at exascale. ALPINE developed a new lightweight in situ infrastructure, Ascent.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

Tuning Catalyst Activation and Utilization Via Controlled Electrode Patterning for Low-Loading and High-Efficiency Water Electrolyzers

An anode electrode concept of thin catalyst-coated liquid/gas diffusion layers (CCLGDLs), by integrating Ir catalysts with Ti thin tunable LGDLs with facile electroplating in proton exchange membrane electrolyzer cells (PEMECs), is proposed. The CCLGDL design with only 0.08 mg Ir cm -2 can achieve comparative cell performances to the conventional commercial electrode design, saving ~97% Ir catalyst and augmenting a catalyst utilization to ~24 times. CCLGDLs with regulated patterns enable insight into how pattern morphology impacts reaction kinetics and catalyst utilization in PEMECs. A specially designed two-sided transparent reaction-visible cell assists the in situ visualization of the PEM/electrode reaction interface for the first time. Oxygen gas is observed accumulating at the reaction interface, limiting the active area and increasing the cell impedances. In this work, it is demonstrated that mass transport in PEMECs can be modified by tuning CCLGDL patterns, thus improving the catalyst activation and utilization. The CCLGDL concept promises a future electrode design strategy with a simplified fabrication process and enhanced catalyst utilization. Furthermore, the CCLGDL concept also shows great potential in being a powerful tool for in situ reaction interface research in PEMECs and other energy conversion devices with solid polymer electrolytes.

08 HYDROGEN↗
DOE OSTI2025

Operando Optical Microscopy for Visualization of Dendrite Growth in an Argyrodite LPSCl–Polymer Composite Electrolyte

Herein, we demonstrate the utility of optical microscopy as an accessible technique for the in situ visualization of dendrite growth within polymer–sulfide composite solid-state electrolytes. The composite electrolyte features in situ polymerization and cross-linking of the polymer between ceramic particles, which opens up extensive opportunities for accelerated materials discovery, given the vast array of acrylate/methacrylate monomers available. Specifically, the cross-linked polymer poly(triethylene glycol dimethacrylate) (poly(TEGDMA)) was observed to effectively fill pores and inhibit dendrite growth at the lithium metal interface, attributed to its glassy state at room temperature. This work represents the first application of optical microscopy to illustrate that the incorporation of glassy, undoped polymers such as poly(TEGDMA) can serve as a viable strategy for dendrite suppression in solid-state composite electrolytes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1998

Simultaneous in situ Optical Monitoring Techniques during Crystal Growth of ZnSe by Physical Vapor Transport

ZnSe crystals grown in sealed ampoules by the physical vapor transport method were monitored in situ using three techniques, simultaneously. A Michelson interferometer was set-up to observe the growth rate and surface morphological evolution. An interference pattern (interferogram) is formed by the interaction between the reflection of a HeNe laser (632.8 nm wavelength) off the crystal-vapor interface and a reference beam from the same laser. Preliminary results indicate that the rate of growth/thermal-etching can be calculated using analog data acquisition and simple fringe counting techniques. Gross surface features may also be observed using a digital frame grabber and fringe analysis software. The second in situ technique uses optical absorption to determine the partial pressures of the vapor species. The Se2 and Zn vapor species present in the sealed ampoule absorb light at characteristic wavelengths. The optical absorption is determined by monitoring the light intensity difference between the sample and reference beams. The Se2 Partial pressure profile along the length of the ampoule was estimated from the vibronic absorption peaks at 340.5, 350.8, 361.3 and 379.2 nm using the Beer's law constants established in the calibration runs of pure Se. Finally, because the high temperature crystal growth furnace contains windows, in situ visual observation of the growing crystal is also possible. The use of these techniques not only permits in situ investigation of high temperature vapor growth of semiconductors, but also offers the potential for real time feed back on the growing crystal and allows the possibility of actively controlling the growth process.

Su, C.- H.↗
DOE OSTI2023

Engineering and characterization of carbohydrate‐binding modules for imaging cellulose fibrils biosynthesis in plant protoplasts

Abstract Carbohydrate binding modules (CBMs) are noncatalytic domains that assist tethered catalytic domains in substrate targeting. CBMs have therefore been used to visualize distinct polysaccharides present in the cell wall of plant cells and tissues. However, most previous studies provide a qualitative analysis of CBM‐polysaccharide interactions, with limited characterization of engineered tandem CBM designs for recognizing polysaccharides like cellulose and limited application of CBM‐based probes to visualize cellulose fibrils synthesis in model plant protoplasts with regenerating cell walls. Here, we examine the dynamic interactions of engineered type‐A CBMs from families 3a and 64 with crystalline cellulose‐I and phosphoric acid swollen cellulose. We generated tandem CBM designs to determine various characteristic properties including binding reversibility toward cellulose‐I using equilibrium binding assays. To compute the adsorption ( nk on ) and desorption ( k off ) rate constants of single versus tandem CBM designs toward nanocrystalline cellulose, we employed dynamic kinetic binding assays using quartz crystal microbalance with dissipation. Our results indicate that tandem CBM3a exhibited the highest adsorption rate to cellulose and displayed reversible binding to both crystalline/amorphous cellulose, unlike other CBM designs, making tandem CBM3a better suited for live plant cell wall biosynthesis imaging applications. We used several engineered CBMs to visualize Arabidopsis thaliana protoplasts with regenerated cell walls using confocal laser scanning microscopy and wide‐field fluorescence microscopy. Lastly, we also demonstrated how CBMs as probe reagents can enable in situ visualization of cellulose fibrils during cell wall regeneration in Arabidopsis protoplasts.

09 BIOMASS FUELS↗
DOE OSTI2020

Role of electron pathway in dimensionally increasing water splitting reaction sites in liquid electrolytes

Hydrogen from water splitting is one of the most promising alternatives for fossil fuels in solving the global energy crisis, while its electrochemical reaction mechanism, especially in liquid electrolytes, remains unclear. Herein, how the electrode conductivity affects the reaction sites of oxygen evolution reactions (OERs) in acidic and alkaline solutions was investigated by employing visualization system and electrochemical testing. Inserting Au nanolayers greatly increased electrode conductivities, improved OER kinetics and reduced cell ohmic resistance, leading to excellent water splitting performances in both acidic and alkaline electrolytes. Furthermore, the in-situ visualization results showed more reaction sites and higher catalyst utilizations were achieved by augmenting the electrode conductivity, and reaction sites increased from 1-dimension to 2-dimension. Additionally, it was discovered that electrical conductivities of acidic and alkaline solutions are insufficient to overcome the sharp drop of potential in the electrical double layer for activating OER uniformly on low-conductivity catalysts, indicating the importance of electrical conductivity of the electrode in acidic and alkaline water electrolyzers. This study provided a guidance on how to develop efficient and compact electrodes for acidic and alkaline water electrolyzer stacks and other electrochemical devices, such as fuel cell, N2 reduction, CO 2 conversion, etc.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗