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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 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS2022

La Soufriere Volcanic Eruptions Launched Gravity Waves Into Space

Atmospheric gravity waves can be excited by explosive volcanic eruptions and may reach Earth's upper atmosphere. In this study, we report on mesoscale concentric gravity waves observed in the mesopause airglow layer following the La Soufriere volcano eruption in April 2021. A large ash plume observed by the spaceborne Multi-angle Imaging SpectroRadiometer instrument on April 10 reached ∼20 km. Temporal evolution of the volcanic ash plume was provided by the GOES-16 Advanced Baseline Imager. Nightglow gravity waves were observed by the Visible Infrared Imaging Radiometer Suite Day Night Band. These waves had horizontal wavelengths of ∼25–40 km, and took about a half-to-1 hr to travel from the tropopause to the mesopause. Some concentric ionospheric disturbance signatures are also seen in Global Navigation Satellite System-total electron content maps. We found the launch of gravity waves to be highly correlated with the elevated ash plume from explosive eruptions.

gravity waves↗
NASA NTRS2022

Volcanic Eruption of Cumbre Vieja, La Palma, Spain: A First Insight to the Particulate Matter Injected in the Troposphere

The volcanic eruption of Cumbre Vieja (La Palma Island, Spain), started on 19 September, 2021, and was declared terminated on 25 December, 2021. A complete set of aerosol measurements were deployed around the volcano within the first month of the eruptive activity. This paper describes the results of the observations made at Tazacorte on the west bank of the island where a polarized micro pulse lidar was deployed. The two and a half months analyzed (16 October – 31 December) reveal that the peak height of the lowermost and strongest volcanic plume did not exceed 3 km (mean of 1.43±0.45 km over the whole period) and was highly variable. It steadily increased until week 11 after the eruption start (and 3 weeks before its end) and started decreasing afterwards. The ash mass concentration has been assessed with a method based on the polarization capability of the instrument. Considering the limitation of current remote sensing techniques to detect large to giant particles, the ash mass concentration on one of the days with the highest ash load is estimated to have peaked in the range 800-3200 μg m(exp -3) in the lowermost layer below 2.5 km.

Cumbre Vieja↗
DOE OSTI2020

Unprecedented Analysis of LA’s Clean Energy Transformation

Jurisdictions like the City of Los Angeles are boldly establishing ambitious energy objectives—and NREL can be a key partner in informing these transitions.The City of Los Angeles is one of several U.S. local governments setting monumental, measurable goals to transform their energy economies. At the direction of its City Council, LA has embarked on a plan to modernize its electricity system infrastructure—aiming for a 100% renewable energy supply by 2045, along with aggressive electrification targets for buildings and vehicles.

LA100↗
DOE OSTI2021

Rapid Laser Reactive Sintering of Garnet Li 6.1 La 3 Zr 2 Al 0.3 O 12 Solid-State Electrolyte

All solid-state lithium-ion batteries (ASSLIBs) have gained significant interest in recent years due to their wide range of applications, including mobile devices, electric vehicles, and grid storage. Garnet-type Li 7 La 3 Zr 2 O 12 (LLZO) solid-state electrolyte (SSE) continues to be a significant player in the fabrication of ASSLIBs with excellent ionic conductivity on the order of 10 -3 S•cm -1 with the integration of dopants and sintering aids to assist conductivity and structural evolution during the sintering procedure. Traditional sintering techniques, such as solid-state sintering (SSS), have been proven to yield desirable crystal structures. However, the low ionic conductivity results from inferior microstructure, and lithium loss is a significant challenge. Recently, a relatively novel sintering process called rapid laser reactive sintering (RLRS) has shown great potential for achieving fully dense solid oxide electrolytes with less surface element loss, resulted in high ionic conductivity. Here, we applied the same RLRS method to fabricate LLZO dense electrolyte with different amounts of aluminum dopants. We hope the rapid high-temperature sintering can densify the electrolyte and avoid the lithium loss for achieving high lithium-ion conductivity. In this work, we optimized multiple combinations of laser parameters (speed, power, and defocus distance), initial precursor composition, and controlled atmospheres to discover the optimal conditions for reaching the efficacious crystal structure, microstructure, and ionic conductivity.

25 ENERGY STORAGE↗
DOE OSTI2022

Modified La—Fe—Si magnetocaloric alloys

A magnetocaloric material comprising a La—Fe—Si based alloy composition that is compositionally modified to include a small but effective amount of at least one of Al, Ga, and In to improve mechanical stability of the alloy (substantially reduce alloy brittleness), improve thermal conductivity, and preserve comparable or provide improved magnetocaloric effects. The alloy composition may be further modified by inclusion of at least one of Co, Mn, Cr, and V as well as interstitial hydrogen.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(SiP3)2 by Materials Project

LaSi2P6 crystallizes in the orthorhombic Cmc2_1 space group. The structure is two-dimensional and consists of sixteen lanthanum molecules; sixteen phosphine molecules; and four Si2P5 sheets oriented in the (0, 1, 0) direction. In each Si2P5 sheet, there are four inequivalent Si4- sites. In the first Si4- site, Si4- is bonded to four P1+ atoms to form corner-sharing SiP4 tetrahedra. There are a spread of Si–P bond distances ranging from 2.20–2.29 Å. In the second Si4- site, Si4- is bonded to four P1+ atoms to form corner-sharing SiP4 tetrahedra. There are a spread of Si–P bond distances ranging from 2.23–2.31 Å. In the third Si4- site, Si4- is bonded to four P1+ atoms to form corner-sharing SiP4 tetrahedra. There are a spread of Si–P bond distances ranging from 2.23–2.28 Å. In the fourth Si4- site, Si4- is bonded to four P1+ atoms to form corner-sharing SiP4 tetrahedra. There are a spread of Si–P bond distances ranging from 2.24–2.29 Å. There are twelve inequivalent P1+ sites. In the first P1+ site, P1+ is bonded in a water-like geometry to two Si4- atoms. In the second P1+ site, P1+ is bonded in a single-bond geometry to one Si4- atom. In the third P1+ site, P1+ is bonded in a water-like geometry to two Si4- atoms. In the fourth P1+ site, P1+ is bonded in a single-bond geometry to one Si4- atom. In the fifth P1+ site, P1+ is bonded in a single-bond geometry to one Si4- atom. In the sixth P1+ site, P1+ is bonded in a water-like geometry to two equivalent Si4- atoms. In the seventh P1+ site, P1+ is bonded in an L-shaped geometry to two equivalent Si4- atoms. In the eighth P1+ site, P1+ is bonded in a single-bond geometry to one Si4- atom. In the ninth P1+ site, P1+ is bonded in a water-like geometry to two equivalent Si4- atoms. In the tenth P1+ site, P1+ is bonded in a water-like geometry to two Si4- atoms. In the eleventh P1+ site, P1+ is bonded in a bent 120 degrees geometry to two Si4- atoms. In the twelfth P1+ site, P1+ is bonded in a water-like geometry to two equivalent Si4- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(P3Os)4 by Materials Project

LaOs4P12 crystallizes in the cubic Im-3 space group. The structure is three-dimensional and consists of two lanthanum molecules and one OsP3 framework. In the OsP3 framework, Os+1.75- is bonded to six equivalent P+0.33+ atoms to form distorted corner-sharing OsP6 octahedra. The corner-sharing octahedral tilt angles are 62°. All Os–P bond lengths are 2.38 Å. P+0.33+ is bonded in a bent 120 degrees geometry to two equivalent Os+1.75- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(WO3)11 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(As3Os)4 by Materials Project

LaOs4As12 crystallizes in the cubic Im-3 space group. The structure is three-dimensional and consists of two lanthanum molecules and one OsAs3 framework. In the OsAs3 framework, Os+1.75- is bonded to six equivalent As+0.33+ atoms to form corner-sharing OsAs6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Os–As bond lengths are 2.48 Å. As+0.33+ is bonded in a bent 120 degrees geometry to two equivalent Os+1.75- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(Mo3Se4)2 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2025

Rapid scalable plasma processing of thin-film Li–La–Zr–O solid-state electrolytes

Solid-state electrolytes, such as lithium lanthanum zirconium oxide (LLZO), show promise as technologies for next-generation high-energy-density batteries, but commercial development has been hindered by a lack of scalable processing methods. Current fabrication methods are costly or require long annealing steps to create dense films. We report an atmospheric pressure blown-arc nitrogen plasma jet process to rapidly form sub-micrometer-thick, dense amorphous LLZO (a-LLZO) films from sol-gel precursors. Films are processed in less than 2 min, an order of magnitude faster than what has previously been reported. We demonstrate 500-nm-thick a-LLZO films processed at 350°C with an ionic conductivity of 2 × 10 −6 S/cm at 30°C and 2 × 10 −3 S/cm at 100°C and a conductance of 19 S at 100°C, the highest conductance of any LLZO phase to date. Here, the films exhibit outstanding smooth surface morphology with low defectivity, advancing atmospheric plasma processing as a scalable processing method for solid-state electrolytes.

25 ENERGY STORAGE↗
DOE OSTI2025

Is a Homologous Series Member Equal to or Greater than the Sum of its Subunits? A Focus on a Few Fe-based BaNiSn3 subunits: LnFeGe3 (Ln = La, Pr)

The homologous series Lnn+1MnGe3n+1 (Ln = Ce, Pr, M = Fe, Co) has proven to be a fruitful platform for tuning physical properties as a function of subunit stacking. In this study, we investigate the crystal growth, structure, and physical properties of PrFeGe3, aiming to deconstruct Pr4Fe3Ge10 (n = 3) into its subunits, including the BaNiSn3 and CeNiSi2 structure types. The electrical resistivity and magnetic susceptibility of PrFeGe3 were measured. The magnetic properties reveal PrFeGe3 to be antiferromagnetic (5 K) with an effective moment of eff = 4.38 B/F.U., larger than the spin-only moment from Pr3+ (3.58 B). Due to the large magnetic moment observed, the oxidation state of the elements was determined using spectroscopic methods including X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. The neutral oxidation state of iron determined from X-ray photoelectron spectroscopy supports itinerant magnetic behavior of iron. Annealing, in tandem with differential scanning calorimetry, revealed PrFeGe3 to be a precursor for the formation of new homologous series members.

36 MATERIALS SCIENCE↗
NASA NTRS1995

El Nino and La Nina Events Simulated by the Cane and Zebiak's Model and Observed with Satellite or in situ Data

The Zebiak and Cane (1987) model is first run in its 'forced mode' where the oceanic part of the model is driven by FSU wind stress anomalies over 1980-1994 to simulate sea surface temperature anomalies and those are used in the atmospheric part of the model to generate wind anomalies. Simulated thermocline depths, sea surface temperature and wind stress anomalies are first validated with observations.

climate research sea temperature sea wind El Nino ↗