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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Electronic and Geometric effects on Photochemistry of Molecules in Well-Defined Environments

Assemblies of molecular switches at surfaces are of great interest for applications in solar energy conversion, optoelectronic and optomechanical devices. Experimental studies have demonstrated that it is possible to optically probe photoactive molecules in well-defined nanoscale environments. To understand these systems, we have developed a polarizable frozen-density embedding (FDEpol) to model the optical properties of molecules adsorbed on metal clusters. We have demonstrated that the FDEpol method can describe the ground state and linear response properties of strongly coupled systems with results that are in good agreement with exact projection based embedding method.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

FY2022 Q4: Demonstrate multi-turbine simulation with hybrid-structured/unstructured-moving-grid software stack running primarily on GPUs and propose improvements for successful KPP-2 [Poster]

Milestone accomplishments staged the ExaWind team for successful completion of KPP-2 challenge problem in FY23, which requires the simulation on Frontier of at least four MW-scale turbines in an atmospheric boundary layer with at least 20B gridpoints. The ExaWind project and software stack is many faceted, with team members working on multiple areas, including linear-system solvers (Trilinos, hypre, AMReX), overset meshes, turbulence modeling, and in situ visualization, all with an aim for high fidelity predictions and performance portability. This milestone marks significant improvements on many fronts and provides the team with a pathway to exascale wind farm simulations in FY23.

17 WIND ENERGY↗
DOE OSTI2023

Magnetoelectronic phenomena due to quantum magnetization fluctuations

The goal of the project was to identify techniques to study magnetoelectronic phenomena such as spin transfer (ST) that stem from the quantum-mechanical nature of magnetization, and utilize them to characterize these quantum phenomena. The first such technique, electronic measurements based on the dependence of resistance on the population of spin-wave quanta (magnons) in a magnetic nanostructure, was shown by detailed measurements to be significantly influenced by the current-driven generation of a highly nonequilibrium phonon distribution by electrical current. This previously unrecognized phenomenon adds to the understanding of current-induced heating phenomena, qualitatively changes the methodology of analysis of current-induced heating common in scientific studies and engineering of current-carrying nanostructures. It benefits the public by providing a new direction for mitigation of Joule heating effects in electronic devices. The project also included quantum simulations of current-induced effects in magnetic nanostructures, which revealed that linear momentum and energy conservation are important for ST. Only angular momentum conservation was previously believed to be important. This finding is important for the fundamental understanding of ST, and for the design of efficient magnetoelectronic devices taking advantage of these conservation laws. Simulations also showed that non-classical ST is dominant in antiferromagnets, which will transform the understanding of ST in these systems. Finally, experimental studies of spin-transfer in ultrathin transition metal films revealed very large non-classical effects which were traced to the quantum origins of magnetism associated in the studied systems with the formation of an orbital liquid state. These findings i) transform the understanding of "conventional" transition-metal magnetism, ii) open a new field of studies in magnetism and a new method for the electronic control of magnetic properties and magnetism itself, and iii) provide a new approach to the development of efficient magnetoelectronic devices.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2024

MULTI-LEADER: MULTI-source LEarning-Accelerated Design of high-Efficiency multi-stage compRessor (Final Technical Report)

The objective of MULTI-LEADER is to cut design costs by 80% while generating more energy-efficient designs of multi-stage compressors by developing and implementing novel machine learning (ML) techniques, which enable faster and fewer design iterations, improved solver performance, and concurrent multi-disciplinary design. Current industrial practices for the design of multi-stage compressors involve simulation-based design optimization with successive levels of model fidelity, iteratively evaluated between distinct disciplines, one stage at a time to tackle the high dimensional design variations. This project addresses these key design challenges: (1) concurrent optimization of multiple stages under many non-linear constraints; (2) multitude of evaluation of high-fidelity and expensive solvers and their gradients during optimization convergence in high-dimensional design; (3) multi-disciplinary design to maximize aerodynamic performance while guaranteeing structural integrity and additive manufacturability; (4) utilization of multiple fidelity of solvers with disparate parameterization and modeling assumptions. MULTI-LEADER achieved more than 5x speed up in detailed design of more energy-efficient compressors via these machine learning (ML) innovations: (i) rapid design surrogates by multi-source learning from diverse fidelities across multiple disciplines, (ii) physics-constrained data-augmented modeling for improved empiricism, (iii) generative manifold embedding for high dimensional concurrent design without gradient information; (iv) budget-constrained fidelity-adaptive sampling towards fewer design iterations.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2025

Consideration of REBCO Rapid-Cycling Diple Magnet for Staged Muon Acceleration

A possible application of the HTS (ReBCO) rapid-cycling dipole magnet [1] in the first stages of muon acceleration consisting of Recirculating Linear Accelerator (RLA) and followed-up first Rapid Cycling Synchrotron (RCS-1) is presented. The projected ReBCO magnet hysteresis loss is discussed in terms of the liquid helium coolant choice and the option with the striated ReBCO conductor for the further significant reduction of the hysteresis power loss.

Piekarz, Henryk [Fermilab] (ORCID:0000000194225662↗
DOE OSTI2020

Increasing the SATS Uncertainty Safety Margin

The Surveillance and Test System (SATS) checks the functionality of ATR’s Plant Protection System (PPS). The analogue linearity test checks that the SATS analog and digital conversions are accurate to +/- 61 mVdc. This project analyzes whether this accuracy range can be increased without impacting the uncertainty analysis of the PPS system.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Materials Data on In2Co3S2 by Materials Project

Co3In2S2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Co is bonded in a distorted linear geometry to four In and two equivalent S atoms. There are two shorter (2.67 Å) and two longer (2.75 Å) Co–In bond lengths. Both Co–S bond lengths are 2.15 Å. There are two inequivalent In sites. In the first In site, In is bonded to six equivalent Co and two equivalent S atoms to form InCo6S2 hexagonal bipyramids that share corners with six equivalent InCo6S2 hexagonal bipyramids and faces with six equivalent InCo6S6 cuboctahedra. Both In–S bond lengths are 3.04 Å. In the second In site, In is bonded to six equivalent Co and six equivalent S atoms to form InCo6S6 cuboctahedra that share corners with six equivalent InCo6S6 cuboctahedra, edges with six equivalent InCo6S6 cuboctahedra, and faces with six equivalent InCo6S2 hexagonal bipyramids. All In–S bond lengths are 3.17 Å. S is bonded in a 3-coordinate geometry to three equivalent Co and four In atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co3(SnS)2 by Materials Project

Co3Sn2S2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Co is bonded in a distorted linear geometry to four Sn and two equivalent S atoms. There are two shorter (2.69 Å) and two longer (2.70 Å) Co–Sn bond lengths. Both Co–S bond lengths are 2.16 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded to six equivalent Co and two equivalent S atoms to form SnCo6S2 hexagonal bipyramids that share corners with six equivalent SnCo6S2 hexagonal bipyramids and edges with six equivalent SnCo6 cuboctahedra. Both Sn–S bond lengths are 2.89 Å. In the second Sn site, Sn is bonded to six equivalent Co atoms to form distorted SnCo6 cuboctahedra that share corners with six equivalent SnCo6 cuboctahedra and edges with six equivalent SnCo6S2 hexagonal bipyramids. S is bonded in a 4-coordinate geometry to three equivalent Co and one Sn atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on In2Ni3S2 by Materials Project

Ni3In2S2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ni is bonded in a distorted linear geometry to four In and two equivalent S atoms. There are two shorter (2.72 Å) and two longer (2.76 Å) Ni–In bond lengths. Both Ni–S bond lengths are 2.17 Å. There are two inequivalent In sites. In the first In site, In is bonded to six equivalent Ni atoms to form distorted InNi6 cuboctahedra that share corners with six equivalent InNi6 cuboctahedra and edges with six equivalent InNi6S2 hexagonal bipyramids. In the second In site, In is bonded to six equivalent Ni and two equivalent S atoms to form InNi6S2 hexagonal bipyramids that share corners with six equivalent InNi6S2 hexagonal bipyramids and edges with six equivalent InNi6 cuboctahedra. Both In–S bond lengths are 3.04 Å. S is bonded in a 4-coordinate geometry to three equivalent Ni and one In atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ni3(PbS)2 by Materials Project

Ni3Pb2S2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ni is bonded in a distorted linear geometry to four Pb and two equivalent S atoms. There are two shorter (2.82 Å) and two longer (2.84 Å) Ni–Pb bond lengths. Both Ni–S bond lengths are 2.18 Å. There are two inequivalent Pb sites. In the first Pb site, Pb is bonded in a hexagonal planar geometry to six equivalent Ni atoms. In the second Pb site, Pb is bonded to six equivalent Ni and two equivalent S atoms to form corner-sharing PbNi6S2 hexagonal bipyramids. Both Pb–S bond lengths are 3.16 Å. S is bonded in a 3-coordinate geometry to three equivalent Ni and one Pb atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiMo2(PO4)3 by Materials Project

LiMo2(PO4)3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Li1+ is bonded in a distorted linear geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.85–2.68 Å. There are three inequivalent Mo4+ sites. In the first Mo4+ site, Mo4+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with six equivalent PO4 tetrahedra and edges with two equivalent MoO6 octahedra. There are two shorter (2.13 Å) and four longer (2.23 Å) Mo–O bond lengths. In the second Mo4+ site, Mo4+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with six equivalent PO4 tetrahedra. There is two shorter (1.96 Å) and four longer (2.01 Å) Mo–O bond length. In the third Mo4+ site, Mo4+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with six PO4 tetrahedra and an edgeedge with one MoO6 octahedra. There are a spread of Mo–O bond distances ranging from 1.97–2.22 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent MoO6 octahedra. The corner-sharing octahedral tilt angles are 45°. There are a spread of P–O bond distances ranging from 1.49–1.59 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent MoO6 octahedra. The corner-sharing octahedra tilt angles range from 40–42°. There is one shorter (1.48 Å) and three longer (1.58 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with six MoO6 octahedra. The corner-sharing octahedra tilt angles range from 42–55°. There are a spread of P–O bond distances ranging from 1.51–1.60 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Mo4+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Mo4+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mo4+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Li1+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo4+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Li1+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Mo4+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo4+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo4+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr3SiNi2 by Materials Project

Cr3Ni2Si crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Cr is bonded in a distorted linear geometry to four equivalent Ni and two equivalent Si atoms. There are two shorter (2.43 Å) and two longer (2.82 Å) Cr–Ni bond lengths. Both Cr–Si bond lengths are 2.80 Å. Ni is bonded to six equivalent Cr, three equivalent Ni, and three equivalent Si atoms to form distorted NiCr6Si3Ni3 cuboctahedra that share corners with three equivalent SiCr6Ni6 cuboctahedra, corners with six equivalent NiCr6Si3Ni3 cuboctahedra, faces with four equivalent SiCr6Ni6 cuboctahedra, and faces with nine equivalent NiCr6Si3Ni3 cuboctahedra. All Ni–Ni bond lengths are 2.48 Å. All Ni–Si bond lengths are 2.25 Å. Si is bonded to six equivalent Cr and six equivalent Ni atoms to form SiCr6Ni6 cuboctahedra that share corners with six equivalent NiCr6Si3Ni3 cuboctahedra, faces with six equivalent SiCr6Ni6 cuboctahedra, and faces with eight equivalent NiCr6Si3Ni3 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HgPb2(ClO)2 by Materials Project

HgPb2(OCl)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Hg2+ is bonded in a distorted linear geometry to two equivalent O2- and four equivalent Cl1- atoms. Both Hg–O bond lengths are 2.08 Å. All Hg–Cl bond lengths are 3.06 Å. Pb2+ is bonded in a 3-coordinate geometry to three equivalent O2- and five equivalent Cl1- atoms. There are one shorter (2.40 Å) and two longer (2.44 Å) Pb–O bond lengths. There are a spread of Pb–Cl bond distances ranging from 3.34–3.47 Å. O2- is bonded to one Hg2+ and three equivalent Pb2+ atoms to form a mixture of corner and edge-sharing OHgPb3 tetrahedra. Cl1- is bonded in a 7-coordinate geometry to two equivalent Hg2+ and five equivalent Pb2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ni3(SnS)2 by Materials Project

Ni3Sn2S2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ni is bonded in a distorted linear geometry to four Sn and two equivalent S atoms. There are two shorter (2.72 Å) and two longer (2.77 Å) Ni–Sn bond lengths. Both Ni–S bond lengths are 2.18 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded to six equivalent Ni and two equivalent S atoms to form corner-sharing SnNi6S2 hexagonal bipyramids. Both Sn–S bond lengths are 2.91 Å. In the second Sn site, Sn is bonded in a distorted hexagonal planar geometry to six equivalent Ni atoms. S is bonded in a 4-coordinate geometry to three equivalent Ni and one Sn atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tl2Ni3S2 by Materials Project

Tl2Ni3S2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ni is bonded in a distorted linear geometry to four Tl and two equivalent S atoms. There are two shorter (2.77 Å) and two longer (2.81 Å) Ni–Tl bond lengths. Both Ni–S bond lengths are 2.17 Å. There are two inequivalent Tl sites. In the first Tl site, Tl is bonded in a distorted hexagonal planar geometry to six equivalent Ni atoms. In the second Tl site, Tl is bonded to six equivalent Ni and two equivalent S atoms to form corner-sharing TlNi6S2 hexagonal bipyramids. Both Tl–S bond lengths are 3.16 Å. S is bonded in a 3-coordinate geometry to three equivalent Ni and one Tl atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ni3(BiS)2 by Materials Project

Ni3Bi2S2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ni is bonded in a distorted linear geometry to four Bi and two equivalent S atoms. There are two shorter (2.77 Å) and two longer (2.91 Å) Ni–Bi bond lengths. Both Ni–S bond lengths are 2.18 Å. There are two inequivalent Bi sites. In the first Bi site, Bi is bonded to six equivalent Ni and two equivalent S atoms to form corner-sharing BiNi6S2 hexagonal bipyramids. Both Bi–S bond lengths are 3.03 Å. In the second Bi site, Bi is bonded in a distorted hexagonal planar geometry to six equivalent Ni atoms. S is bonded in a 4-coordinate geometry to three equivalent Ni and one Bi atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbLa9(IrO6)4 by Materials Project

RbLa9(IrO6)4 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. Rb1+ is bonded in a distorted linear geometry to two equivalent O2- atoms. Both Rb–O bond lengths are 2.69 Å. There are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of La–O bond distances ranging from 2.44–2.89 Å. In the second La3+ site, La3+ is bonded to six O2- atoms to form LaO6 octahedra that share corners with six IrO6 octahedra. The corner-sharing octahedra tilt angles range from 0–56°. There are two shorter (2.28 Å) and four longer (2.47 Å) La–O bond lengths. There are two inequivalent Ir5+ sites. In the first Ir5+ site, Ir5+ is bonded to six O2- atoms to form IrO6 octahedra that share corners with two equivalent LaO6 octahedra. The corner-sharing octahedral tilt angles are 56°. There is two shorter (1.95 Å) and four longer (2.04 Å) Ir–O bond length. In the second Ir5+ site, Ir5+ is bonded to six O2- atoms to form IrO6 octahedra that share a cornercorner with one LaO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Ir–O bond distances ranging from 1.95–2.02 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Ir5+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to five La3+ and one Ir5+ atom. In the third O2- site, O2- is bonded to one Rb1+, four equivalent La3+, and one Ir5+ atom to form distorted corner-sharing ORbLa4Ir octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent La3+ and one Ir5+ atom. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent La3+ and one Ir5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li2(VS2)3 by Materials Project

Li2(VS2)3 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. Li1+ is bonded in a linear geometry to two equivalent S2- atoms. Both Li–S bond lengths are 2.29 Å. V+3.33+ is bonded to six S2- atoms to form distorted edge-sharing VS6 pentagonal pyramids. There are two shorter (2.35 Å) and four longer (2.37 Å) V–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to one Li1+ and three equivalent V+3.33+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent V+3.33+ atoms.

36 MATERIALS SCIENCE↗