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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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138 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Enhanced Rock Weathering for Carbon Dioxide Removal: Life Cycle Analysis and Techno-Economic Assessment

The study models enhanced rock weathering (ERW) using minerals such as basalt and olivine in terrestrial environments. Our analysis shows potential for ERW CO2 removal and storage costs to approach US$ 100 per tonne (t) of CO2 removed and stored under certain conditions (2023 dollars). In the environmental analysis, the 100-year global warming potential impact with igneous rock and industrial waste materials ranges from 34–263 and 23–180 kg CO2-eq per tonne of CO2 removed and stored, respectively (these values result in overall emissions (removed minus emitted) between –977 and –737 kg CO2-eq net removed per tonne of CO2 removed and stored, meaning for every tonne of CO2 removed by ERW, after accounting for the CO2 equivalent emissions from the GWP, the overall emissions are negative.

Priyadarshini, NFN [NETL Site Support Contractor, ↗
DOE OSTI2025

Deployment and Evaluation of SciStream on OLCF's Advanced Computing Ecosystem (ACE)

The growing demand for real-time analysis, experimental steering, and decision-making in scientific workflows has created a need for tightly coupled integrations between experimental facilities and high-performance computing (HPC) systems. The Department of Energy’s Integrated Research Infrastructure (IRI) initiative highlights data streaming as a key capability for enabling memory-to-memory data transfers, bypassing the limitations of traditional store-and-forward models. SciStream is a toolkit developed by researchers at Argonne National Laboratory (ANL) to support such streaming by addressing cross-domain security, delegated authentication, and application transparency. We deployed and evaluated SciStream on the Oak Ridge Leadership Computing Facility’s (OLCF) Advanced Computing Ecosystem (ACE) infrastructure, leveraging the Olivine OpenShift cluster and its high-bandwidth Data Streaming Nodes (DSNs) as gateway nodes. Our evaluation included synthetic streaming workloads derived from IRI science workflows, a streaming simulator, and integration with RabbitMQ to handle low-level messaging. This report documents the deployment process, performance evaluation, and challenges encountered, along with opportunities for future improvements.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2020

The Elastic Properties of β-Mg 2 SiO 4 Containing 0.73 wt.% of H 2 O to 10 GPa and 600 K by Ultrasonic Interferometry with Synchrotron X-Radiation

Here, we measured the elastic velocities of a synthetic polycrystalline β-Mg 2 SiO 4 containing 0.73 wt.% H 2 O to 10 GPa and 600 K using ultrasonic interferometry combined with synchrotron X-radiation. Third-order Eulerian finite strain analysis of the high P and T data set yielded K so = 161.5(2) GPa, G o = 101.6(1) GPa, and (∂K s /∂P) T = 4.84(4), (∂G/∂P) T = 1.68(2) indistinguishable from K so = 161.1(3) GPa, G o = 101.4(1) GPa, and (∂K s /∂P) T = 4.93(4), (∂G/∂P) T = 1.73(2) from the linear fit. The hydration of the wadsleyite by 0.73 wt.% decreases K s and G moduli by 5.3% and 8.6%, respectively, but no measurable effect was noted for (∂K s /∂P) T and (∂G/∂P) T . The temperature derivatives of the K s and G moduli from the finite strain analysis (∂K S /∂T) P = –0.013(2) GPaK –1 , (∂G/∂T) P = –0.015(0.4) GPaK –1 , and the linear fit (∂K S /∂T) P = –0.015(1) GPaK –1 , (∂G/∂T) P = –0.016(1) GPaK –1 are in agreement, and both data sets indicating the |(∂G/∂T) P | to be greater than |(∂K S /∂T) P |. Calculations yield ΔV p(α-β) = 9.88% and ΔV S(α-β) = 8.70% for the hydrous β-Mg 2 SiO 4 and hydrous α-Mg 2 SiO 4 , implying 46–52% olivine volume content in the Earth’s mantle to satisfy the seismic velocity contrast ΔV s = ΔV P = 4.6% at the 410 km depth.

58 GEOSCIENCES↗
DOE OSTI2021

Composition and Pressure Effects on Partitioning of Ferrous Iron in Iron-Rich Lower Mantle Heterogeneities

Both seismic observations of dense low shear velocity regions and models of magma ocean crystallization and mantle dynamics support enrichment of iron in Earth’s lowermost mantle. Physical properties of iron-rich lower mantle heterogeneities in the modern Earth depend on distribution of iron between coexisting lower mantle phases (Mg,Fe)O magnesiowüstite, (Mg,Fe)SiO3 bridgmanite, and (Mg,Fe)SiO3 post-perovskite. The partitioning of iron between these phases was investigated in synthetic ferrous-iron-rich olivine compositions (Mg0.55Fe0.45)2SiO4 and (Mg0.28Fe0.72)2SiO4 at lower mantle conditions ranging from 33–128 GPa and 1900–3000 K in the laser-heated diamond anvil cell. The resulting phase assemblages were characterized by a combination of in situ X-ray diffraction and ex situ transmission electron microscopy. The exchange coefficient between bridgmanite and magnesiowüstite decreases with pressure and bulk Fe# and increases with temperature. Thermodynamic modeling determines that incorporation and partitioning of iron in bridgmanite are explained well by excess volume associated with Mg-Fe exchange. Partitioning results are used to model compositions and densities of mantle phase assemblages as a function of pressure, FeO-content and SiO2-content. Unlike average mantle compositions, iron-rich compositions in the mantle exhibit negative dependence of density on SiO2-content at all mantle depths, an important finding for interpretation of deep lower mantle structures.

Dorfman, Susannah M. (ORCID:0000000239689592)↗
DOE OSTI2020

A New Method for Deriving Composition of S-type Asteroids from Noisy and Incomplete Near-infrared Spectra

The surface composition of S-type asteroids can be determined using band parameters extracted from their near-infrared (NIR) spectra (0.7–2.50 μm) along with spectral calibrations derived from laboratory samples. In the past, these empirical equations have been obtained by combining NIR spectra of meteorite samples with information about their composition and mineral abundance. For these equations to give accurate results, the characteristics of the laboratory spectra they are derived from should be similar to those of asteroid spectral data (i.e., similar signal-to-noise ratio (S/N) and wavelength range). Here we present new spectral calibrations that can be used to determine the mineral composition of ordinary chondrite-like S-type asteroids. Contrary to previous work, the S/N of the ordinary chondrite spectra used in this study has been decreased to recreate the S/N typically observed among asteroid spectra, allowing us to obtain more realistic results. In addition, the new equations have been derived for five wavelength ranges encompassed between 0.7 and 2.50 μm, making it possible to determine the composition of asteroids with incomplete data. The new spectral calibrations were tested using band parameters measured from the NIR spectrum of asteroid (25143) Itokawa, and comparing the results with laboratory measurements of the returned samples. We found that the spectrally derived olivine and pyroxene chemistry, which are given by the molar contents of fayalite (Fa) and ferrosilite (Fs), are in excellent agreement with the mean values measured from the samples (Fa{sub 28.6±1.1} and Fs{sub 23.1±2.2}), with a maximum difference of 0.6 mol% for Fa and 1.4 mol% for Fs.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2025

Spectroscopy of the Hamburg Meteorite, Michigan H4

Spectroscopic studies of the Hamburg (Michigan H4) meteorite using visible–near-infrared (VNIR), mid-infrared (MIR), Raman, and Mössbauer data reproduce the results of more conventional laboratory measurements of petrology and geochemistry. This combination provides general information on the mineral modes of silicates, although spectroscopy was performed on different splits of this meteorite, and varying results may be explained by heterogeneity that is typical of ordinary chondrites. Raman also detects small features assigned to first-order D and G carbon bands, while Mössbauer data show the presence of Fe oxides and carbides. The electron microprobe (EMPA) composition of olivine in this meteorite is accurately measured to be Fo 81.3 , while MIR and Raman closely agree with Fo 80 and Fo 82 , respectively, and Mössbauer, at Fo 60 − Fo 70 , is in the ballpark. Similarly, P. R. Heck et al. report pyroxenes with compositions of Fs 16 Wo 1 , while Raman suggests a somewhat similar composition of Fs 28 Wo 0 . Both VNIR and MIR detect the presence of small amounts of feldspar, while EMPA identifies its composition as An 14 Ab 8 Or 5 . VNIR data were matched to spectral libraries of meteorite and asteroid data and shown to closely match other L and H meteorites. The best spectral matches to the Michigan H4 meteorite are to asteroid classes L/H/LL/URE, EH/EL/AUB, and CO/CV from M. D. Dyar et al.; objects in this group are intermediate in semimajor axis lengths for their orbits. The results highlight the strengths and weaknesses of each technique and show their collective strength when applied together to a single meteorite sample.

58 GEOSCIENCES↗
DOE OSTI2022

Next-Generation Cobalt-Free Cathodes – A Prospective Solution to the Battery Industry's Cobalt Problem*

Lithium-ion batteries are over-reliant on cobalt-containing cathodes. Current projections estimate hundreds of millions of electric vehicles (EVs) will be on the road by 2050, and this ever-growing demand threatens to deplete global cobalt reserves at an alarming rate. Moreover, cobalt supply-chain issues have significantly increased cobalt prices throughout the last decade. As such, energy storage research and development need to reduce reliance on cobalt to meet ever-growing demands for lithium-ion batteries. This chapter summarizes the science/technology gaps and potential of numerous cobalt-free Li-ion cathodes, including layered, spinel, olivine, and disordered rocksalt systems. Despite the promising performance of these Co-free cathodes, scale-up and manufacturing bottlenecks associated with these materials must also be addressed to enable widespread adoption in commercial batteries. Overall, this review broadly highlights the enormous promise of “zero-cobalt” Li-ion batteries to enable sustainable production of EVs in the coming decades.

Muralidharan, Nitin↗
DOE OSTI2025

Ab Initio Structures and Energetics of Hydrated Flat and Terrace-Step Surfaces of Forsterite (Mg 2 SiO 4 )

Forsterite (Mg 2 SiO 4 ), a model divalent metal silicate mineral, has been extensively studied in the context of mineral carbonation. Although dissolution is a key step in this process, the mechanisms by which forsterite dissolves under high CO 2 conditions remain poorly understood. Atomistic simulations could aid in exploring these mechanisms, but it is essential first to understand the structures and energetics of the relevant forsterite surfaces. We present an ab initio study of the structure and surface energy at 0 K of the flat $(010), (110), (001), (111), (021), (101)$ and $(120)$ faces of forsterite using the density functional PBE Hamiltonian and a plane-wave basis set. Dry surfaces became stabilized upon hydration through the formation of bonds between surface Mg and O from water, as well as by the formation of hydrogen bonds. According to surface energy values, the stability order of the hydrated forsterite faces was found to be $(120) < (101) < (021) < (111) < (001) < (110) < (010)$. We also investigated the energetics of the terrace-step $(0\bar{41})$ surface as a model site for forsterite dissolution. Among all the facets, the $(0\bar{41})$ surface is the least stable termination in water. Hydration of Mg atoms on the $(0\bar{41})$ surface increases their susceptibility to dissolution. The presence of a step and its hydration destabilizes the terraces, making step retreat more likely than a dissolution front advancing along the [010] direction. This research will support future simulations to investigate forsterite dissolution in water under CO 2 -rich conditions.

PBE Hamiltonian↗
DOE OSTI2020

Femtosecond X-ray Diffraction of Laser-shocked Forsterite (Mg 2 SiO 4 ) to 122 GPa

The response of forsterite, Mg 2 SiO 4 , under dynamic compression is of fundamental importance for understanding its phase transformations and high-pressure behavior. Here, we have carried out an in situ X-ray diffraction study of laser-shocked polycrystalline and single-crystal forsterite from 19 to 122 GPa using the Matter in Extreme Conditions end-station of the Linac Coherent Light Source. Under laser-based shock loading, forsterite does not transform to the high-pressure equilibrium assemblage of MgSiO 3 bridgmanite and MgO periclase, as has been suggested previously. Instead, we observe forsterite and forsterite III, a metastable polymorph of Mg 2 SiO 4 , coexisting in a mixed-phase region from 33 to 75 GPa for both polycrystalline and single-crystal samples. Densities inferred from X-ray diffraction are consistent with earlier gas-gun shock data. At higher stress, the response is sample-dependent. Polycrystalline samples undergo amorphization above 79 GPa. For [010]- and [001]-oriented crystals, a mixture of crystalline and amorphous material is observed to 108 GPa, whereas the [100]-oriented forsterite adopts an unknown phase at 122 GPa. The first two sharp diffraction peaks of amorphous Mg 2 SiO 4 show a similar trend with compression as those observed for MgSiO 3 in both recent static- and laser-driven shock experiments. This study provides new insight into the transformation of forsterite under nanosecond-duration shock loading. This work emphasizes the importance of formation of metastable phases along the Hugoniot and adds to evidence that the 300-K single-crystal diamond anvil cell experiments have relevance for understanding structures formed under shock compression. In particular, the metastable phase forsterite III has now been shown to form under dynamic compression from 10s to 100s of nanoseconds as well as under 300-K static compression. Upon compression to higher pressures, Mg 2 SiO 4 transforms to an amorphous phase. These results have broad relevance for understanding the behavior of silicates under dynamic compression.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Delineating the kinetic limitations of Mn 2+/3+ redox in LiMn x Fe 1−x PO 4 cathodes for lithium-ion batteries

LiMn x Fe 1−x PO 4 (LMFP) cathodes offer higher energy density than LiFePO 4 due to a higher operating voltage. However, the kinetic limitations of the Mn 2+/3+ redox couple in LMFP restrict its practically achievable capacity and hinder the ability to achieve high energy density. While the shortcomings of Mn 2+/3+ redox are recognized, its behavior and the factors that impact it remain to be fully understood. We present here an in-depth kinetics study of LMFP by utilizing novel techniques, such as chronoamperometry and galvanostatic electrochemical impedance spectroscopy. Compared to moderate-Mn LMFP (40–60% Mn), high-Mn LMFP (80% Mn) experiences reduced capacity, poor rate capability, and heightened impedance during Mn 2+/3+ redox. The oxidation of Mn 2+ to Mn 3+ becomes more resistive during charge due to the formation of Jahn–Teller active Mn 3+ and the increasing charge-transfer insulating behavior of Mn x Fe 1−x PO 4 . However, the impedance associated with Mn 3+ to Mn 2+ reduction remains constant during discharge in the entire region. The protracted Mn2+ oxidation in high-Mn LMFP results in excessive impedance compared to that in moderate-Mn LMFP, even at low C-rates and high cycling temperatures. Despite the promise of high energy density, the extreme kinetic limitations inherent to high-Mn LMFP present a barrier.

25 ENERGY STORAGE↗
DOE OSTI2023

CasDinG is a 5′-3′ dsDNA and RNA/DNA helicase with three accessory domains essential for type IV CRISPR immunity

Abstract CRISPR-associated DinG protein (CasDinG) is essential to type IV-A CRISPR function. Here, we demonstrate that CasDinG from Pseudomonas aeruginosa strain 83 is an ATP-dependent 5′-3′ DNA translocase that unwinds double-stranded (ds)DNA and RNA/DNA hybrids. The crystal structure of CasDinG reveals a superfamily 2 helicase core of two RecA-like domains with three accessory domains (N-terminal, arch, and vestigial FeS). To examine the in vivo function of these domains, we identified the preferred PAM sequence for the type IV-A system (5′-GNAWN-3′ on the 5′-side of the target) with a plasmid library and performed plasmid clearance assays with domain deletion mutants. Plasmid clearance assays demonstrated that all three domains are essential for type IV-A immunity. Protein expression and biochemical assays suggested the vFeS domain is needed for protein stability and the arch for helicase activity. However, deletion of the N-terminal domain did not impair ATPase, ssDNA binding, or helicase activities, indicating a role distinct from canonical helicase activities that structure prediction tools suggest involves interaction with dsDNA. This work demonstrates CasDinG helicase activity is essential for type IV-A CRISPR immunity as well as the yet undetermined activity of the CasDinG N-terminal domain.

59 BASIC BIOLOGICAL SCIENCES↗