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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 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Impact of Mixed Sources on the Atmospheric Aerosols of Urbanized Areas in the Philippines

Southeast Asia (SEA) holds approximately 10% of the global population, who are constantly exposed to severe local and transboundary air pollution. Here, we characterized the physiochemical characteristics of atmospheric aerosols in urbanized areas (Valenzuela, Manila, and Boracay) in the Philippines. The variability of coarse and fine aerosols, black carbon (BC), and trace elements of particulate matter (PM) were analyzed between June 2017 and April 2019. The average fine (coarse) aerosols of Valenzuela, Manila, and Boracay were 26.7 (80.4), 27.9 (86.6), and 20.9 (124.6) µg m –3 , respectively, which all exceeded the recent annual limits of the World Health Organization. The average BC level was 6.6 µg m –3 across three sampling sites, ranging between 4 to 83% of the fine PM mass. Vehicular emission predominated at the extreme urban sites as reflected by the high BC levels attributed to transport activities. The conventional receptor modeling procedure was implemented and improved by integrating BC speciation, which distinguished vehicle emission and biomass burning. The new method revealed eight and seven sources influencing the atmospheric conditions of Valenzuela and Boracay. In particular, the elevated zinc and lead highlighted the substantial impact of industrial sources in Valenzuela, attributing more than 9% of PM 2.5 . For Boracay, construction activities evidently enhanced PM based on the mass burden of calcium. Overall, the results uncovered the origin of PM 2.5 in urbanized locations in the Philippines, which will be valuable in reducing the exposure of a significant portion of the global population to harmful pollutants.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

A Review and Perspective on Particulate Matter Indices Linking Fuel Composition to Particulate Emissions from Gasoline Engines

Particulate matter (PM) indices - those linking PM emissions from gasoline engines to the composition and properties of the fuel - have been a topic of significant study over the last decade. It has long been known that fuel composition has a significant impact on particulate emissions from gasoline engines. Since gasoline direct injection (GDI) engines have become the market-leading technology, this has become more significant because the evaporative behavior of fuel increases in importance. Several PM indices have been developed to provide metrics describing this behavior and correlating PM emissions. In this article, 16 different PM indices are identified and collected - to the authors' knowledge, all of the indices are available at the time of writing. The indices are reviewed and discussed in the context of the information required to calculate them, as well as their utility. Additionally, the authors believe that there is a need for indices that provide both a detailed and robust correlation, as well as those that are less sophisticated yet sufficient for specific use cases. Future research is suggested to guide the technical community toward improvements in the indices' methods and equations for both high and low fidelity and high and low time investment.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2023

Quantitative chemical assay of nanogram-level particulate matter using aerosol mass spectrometry: characterization of particles collected from uncrewed atmospheric measurement platforms

Abstract. Aerosol generation techniques have expanded the utility of aerosol mass spectrometry (AMS) for offline chemical analysis of airborne particles and droplets. However, standard aerosolization techniques require relatively large liquid volumes (e.g., several milliliters) and high sample masses that limit their utility. Here we report the development and characterization of a micronebulization AMS (MN-AMS) technique that requires as low as 10 µL of sample and can provide the quantification of the nanogram level of organic and inorganic substances via the usage of an isotopically labeled internal standard (34SO42-). Using standard solutions, the detection limits for this technique were determined at 0.19, 0.75, and 2.2 ng for sulfate, nitrate, and organics, respectively. The analytical recoveries for these species are 104 %, 87 %, and 94 %, respectively. This MN-AMS technique was applied successfully to analyze filter and impactor samples collected using miniature particulate matter (PM) samplers deployable on uncrewed atmospheric measurement platforms, such as uncrewed aerial systems (UASs) and tethered balloon systems (TBSs). Chemical composition of PM samples collected from a UAS field campaign conducted at the Department of Energy's (DOE) Southern Great Plains (SGP) observatory was characterized. The offline MN-AMS data compared well with the in situ PM composition measured by a co-located aerosol chemical speciation monitor (ACSM). In addition, the MN-AMS and ion chromatography (IC) agreed well for measurements of sulfate and nitrate concentrations in the PM extracts. This study demonstrates the utility of combining MN-AMS with uncrewed measurement platforms to provide quantitative measurements of ambient PM composition.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Machining of Wrought Alloy 316L Specimens to Evaluate Elevated-Temperature Fatigue and Creep-Fatigue Properties

At the 2019 GAIN Microreactors workshop, a need to fabricate microreactor components through advanced manufacturing (AM) was conveyed by microreactor developers. Powder metallurgy (PM) hot isostatic pressing (HIP) is more mature than other AM techniques and thus more readily deployable in the near term. The elevated-temperature cyclic properties of materials manufactured by PM HIP, however, have not been established. Work is currently in progress to evaluate the elevated-temperature cyclic properties of Alloy 316L manufactured by PM HIP. These properties need to be compared to those of wrought Alloy 316L in order to understand the effect of PM HIP. Therefore, wrought Alloy 316L testing at the same conditions as those tested for the PM HIP is necessary. This statement of work provides instructions and requirements for the machining of wrought Alloy 316L specimens.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

System and method for high power diode based additive manufacturing

The present disclosure relates to a system for performing an Additive Manufacturing (AM) fabrication process on a powdered material (PM) forming a substrate. The system uses a first optical subsystem to generate an optical signal comprised of electromagnetic (EM) radiation sufficient to melt or sinter a PM of the substrate. The first optical subsystem is controlled to generate a plurality of different power density levels, with a specific one being selected based on a specific PM forming a powder bed being used to form a 3D part. At least one processor controls the first optical subsystem and adjusts a power density level of the optical signal, taking into account a composition of the PM. A second optical subsystem receives the optical signal from the first optical subsystem and controls the optical signal to help facilitate melting of the PM in a layer-by-layer sequence of operations.

El-Dasher, Bassem S.↗
DOE OSTI2020

Materials Data on Pm3Ge by Materials Project

Pm3Ge is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pm is bonded in a distorted square co-planar geometry to four equivalent Ge atoms. All Pm–Ge bond lengths are 3.40 Å. Ge is bonded to twelve equivalent Pm atoms to form a mixture of face and corner-sharing GePm12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmAg3 by Materials Project

PmAg3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Pm is bonded in a distorted body-centered cubic geometry to fourteen Ag atoms. There are eight shorter (3.06 Å) and six longer (3.53 Å) Pm–Ag bond lengths. There are two inequivalent Ag sites. In the first Ag site, Ag is bonded to four equivalent Pm and four equivalent Ag atoms to form a mixture of distorted face, edge, and corner-sharing AgPm4Ag4 tetrahedra. All Ag–Ag bond lengths are 3.06 Å. In the second Ag site, Ag is bonded in a 8-coordinate geometry to six equivalent Pm and eight equivalent Ag atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmCd3 by Materials Project

PmCd3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Pm is bonded in a distorted body-centered cubic geometry to fourteen Cd atoms. There are eight shorter (3.16 Å) and six longer (3.65 Å) Pm–Cd bond lengths. There are two inequivalent Cd sites. In the first Cd site, Cd is bonded in a distorted body-centered cubic geometry to four equivalent Pm and four equivalent Cd atoms. All Cd–Cd bond lengths are 3.16 Å. In the second Cd site, Cd is bonded in a 8-coordinate geometry to six equivalent Pm and eight equivalent Cd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmIn3 by Materials Project

PmIn3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pm is bonded to twelve equivalent In atoms to form PmIn12 cuboctahedra that share corners with twelve equivalent PmIn12 cuboctahedra, edges with twenty-four equivalent InPm4In8 cuboctahedra, faces with six equivalent PmIn12 cuboctahedra, and faces with twelve equivalent InPm4In8 cuboctahedra. All Pm–In bond lengths are 3.33 Å. In is bonded to four equivalent Pm and eight equivalent In atoms to form distorted InPm4In8 cuboctahedra that share corners with twelve equivalent InPm4In8 cuboctahedra, edges with eight equivalent PmIn12 cuboctahedra, edges with sixteen equivalent InPm4In8 cuboctahedra, faces with four equivalent PmIn12 cuboctahedra, and faces with fourteen equivalent InPm4In8 cuboctahedra. All In–In bond lengths are 3.33 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmPd3 by Materials Project

PmPd3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pm is bonded to twelve equivalent Pd atoms to form a mixture of face and corner-sharing PmPd12 cuboctahedra. All Pm–Pd bond lengths are 2.96 Å. Pd is bonded in a distorted square co-planar geometry to four equivalent Pm atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmRh3 by Materials Project

PmRh3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pm is bonded to twelve equivalent Rh atoms to form a mixture of face and corner-sharing PmRh12 cuboctahedra. All Pm–Rh bond lengths are 2.91 Å. Rh is bonded in a distorted square co-planar geometry to four equivalent Pm atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmSn3 by Materials Project

PmSn3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pm is bonded to twelve equivalent Sn atoms to form a mixture of face and corner-sharing PmSn12 cuboctahedra. All Pm–Sn bond lengths are 3.37 Å. Sn is bonded in a distorted square co-planar geometry to four equivalent Pm atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmTl3 by Materials Project

PmTl3 is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pm is bonded to twelve equivalent Tl atoms to form PmTl12 cuboctahedra that share corners with twelve equivalent PmTl12 cuboctahedra, edges with twenty-four equivalent TlPm4Tl8 cuboctahedra, faces with six equivalent PmTl12 cuboctahedra, and faces with twelve equivalent TlPm4Tl8 cuboctahedra. All Pm–Tl bond lengths are 3.41 Å. Tl is bonded to four equivalent Pm and eight equivalent Tl atoms to form distorted TlPm4Tl8 cuboctahedra that share corners with twelve equivalent TlPm4Tl8 cuboctahedra, edges with eight equivalent PmTl12 cuboctahedra, edges with sixteen equivalent TlPm4Tl8 cuboctahedra, faces with four equivalent PmTl12 cuboctahedra, and faces with fourteen equivalent TlPm4Tl8 cuboctahedra. All Tl–Tl bond lengths are 3.41 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pm3Sn by Materials Project

Pm3Sn is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pm is bonded in a distorted square co-planar geometry to four equivalent Sn atoms. All Pm–Sn bond lengths are 3.49 Å. Sn is bonded to twelve equivalent Pm atoms to form a mixture of corner and face-sharing SnPm12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pm3Pb by Materials Project

Pm3Pb is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pm is bonded in a distorted square co-planar geometry to four equivalent Pb atoms. All Pm–Pb bond lengths are 3.52 Å. Pb is bonded to twelve equivalent Pm atoms to form a mixture of face and corner-sharing PbPm12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmBi3 by Materials Project

PmBi3 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pm is bonded to twelve Bi atoms to form a mixture of edge, face, and corner-sharing PmBi12 cuboctahedra. There are four shorter (3.34 Å) and eight longer (3.65 Å) Pm–Bi bond lengths. There are two inequivalent Bi sites. In the first Bi site, Bi is bonded in a 12-coordinate geometry to four equivalent Pm and four equivalent Bi atoms. All Bi–Bi bond lengths are 3.34 Å. In the second Bi site, Bi is bonded in a square co-planar geometry to four equivalent Pm atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmMg by Materials Project

MgPm is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Mg is bonded in a body-centered cubic geometry to eight equivalent Pm atoms. All Mg–Pm bond lengths are 3.34 Å. Pm is bonded in a body-centered cubic geometry to eight equivalent Mg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PmSm3 by Materials Project

Sm3Pm is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Sm is bonded to eight equivalent Sm and four equivalent Pm atoms to form SmPm4Sm8 cuboctahedra that share corners with twelve equivalent SmPm4Sm8 cuboctahedra, edges with eight equivalent PmSm12 cuboctahedra, edges with sixteen equivalent SmPm4Sm8 cuboctahedra, faces with four equivalent PmSm12 cuboctahedra, and faces with fourteen equivalent SmPm4Sm8 cuboctahedra. All Sm–Sm bond lengths are 3.64 Å. All Sm–Pm bond lengths are 3.64 Å. Pm is bonded to twelve equivalent Sm atoms to form PmSm12 cuboctahedra that share corners with twelve equivalent PmSm12 cuboctahedra, edges with twenty-four equivalent SmPm4Sm8 cuboctahedra, faces with six equivalent PmSm12 cuboctahedra, and faces with twelve equivalent SmPm4Sm8 cuboctahedra.

36 MATERIALS SCIENCE↗