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At least 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on YCr2Si2C by Materials Project

YCr2Si2C crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Y3+ is bonded in a distorted linear geometry to eight equivalent Si4- and two equivalent C4- atoms. All Y–Si bond lengths are 3.05 Å. Both Y–C bond lengths are 2.63 Å. Cr+4.50+ is bonded in a distorted linear geometry to four equivalent Si4- and two equivalent C4- atoms. All Cr–Si bond lengths are 2.44 Å. Both Cr–C bond lengths are 1.98 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Y3+, four equivalent Cr+4.50+, and one Si4- atom. The Si–Si bond length is 2.41 Å. C4- is bonded to two equivalent Y3+ and four equivalent Cr+4.50+ atoms to form corner-sharing CY2Cr4 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SmV2O2 by Materials Project

SmV2O2 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. Sm is bonded in a linear geometry to two equivalent O atoms. Both Sm–O bond lengths are 2.24 Å. V is bonded in a 1-coordinate geometry to three equivalent O atoms. There are one shorter (2.04 Å) and two longer (2.31 Å) V–O bond lengths. O is bonded in a distorted rectangular see-saw-like geometry to one Sm and three equivalent V atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BeCo2Si by Materials Project

BeCo2Si crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Be2+ is bonded in a distorted linear geometry to two equivalent Si4- atoms. Both Be–Si bond lengths are 2.62 Å. Co1+ is bonded in a 4-coordinate geometry to four equivalent Si4- atoms. All Co–Si bond lengths are 2.34 Å. Si4- is bonded in a 10-coordinate geometry to two equivalent Be2+ and eight equivalent Co1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on DyCr2Si2C by Materials Project

DyCr2Si2C crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Dy3+ is bonded in a distorted linear geometry to eight equivalent Si4- and two equivalent C4- atoms. All Dy–Si bond lengths are 3.06 Å. Both Dy–C bond lengths are 2.62 Å. Cr+4.50+ is bonded in a distorted linear geometry to four equivalent Si4- and two equivalent C4- atoms. All Cr–Si bond lengths are 2.44 Å. Both Cr–C bond lengths are 1.99 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Dy3+, four equivalent Cr+4.50+, and one Si4- atom. The Si–Si bond length is 2.40 Å. C4- is bonded to two equivalent Dy3+ and four equivalent Cr+4.50+ atoms to form corner-sharing CDy2Cr4 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaAl2BOs2 by Materials Project

LaOs2Al2B crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. La is bonded in a distorted linear geometry to two equivalent B atoms. Both La–B bond lengths are 2.83 Å. Os is bonded to four equivalent Al and two equivalent B atoms to form a mixture of corner, edge, and face-sharing OsAl4B2 octahedra. The corner-sharing octahedral tilt angles are 0°. All Os–Al bond lengths are 2.58 Å. Both Os–B bond lengths are 2.12 Å. Al is bonded in a 4-coordinate geometry to four equivalent Os atoms. B is bonded to two equivalent La and four equivalent Os atoms to form corner-sharing BLa2Os4 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiAlH2 by Materials Project

LiAlH2 crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Li is bonded in a linear geometry to two equivalent H atoms. Both Li–H bond lengths are 1.99 Å. Al is bonded in a distorted square co-planar geometry to four equivalent H atoms. All Al–H bond lengths are 1.80 Å. H is bonded in a trigonal non-coplanar geometry to one Li and two equivalent Al atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiSbWO7 by Materials Project

LiWSbO7 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Li is bonded in a distorted linear geometry to four O atoms. There are two shorter (1.95 Å) and two longer (2.55 Å) Li–O bond lengths. W is bonded to six O atoms to form WO6 octahedra that share corners with two equivalent WO6 octahedra and corners with four equivalent SbO6 octahedra. The corner-sharing octahedra tilt angles range from 34–41°. There is four shorter (1.94 Å) and two longer (1.95 Å) W–O bond length. Sb is bonded to six O atoms to form SbO6 octahedra that share corners with two equivalent SbO6 octahedra and corners with four equivalent WO6 octahedra. The corner-sharing octahedra tilt angles range from 41–49°. There are four shorter (1.99 Å) and two longer (2.03 Å) Sb–O bond lengths. There are four inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two equivalent Li atoms. In the second O site, O is bonded in a distorted bent 150 degrees geometry to one W and one Sb atom. In the third O site, O is bonded in a bent 150 degrees geometry to two equivalent W atoms. In the fourth O site, O is bonded in a 4-coordinate geometry to two equivalent Li and two equivalent Sb atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaGa4Fe9C by Materials Project

LaFe9Ga4C crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. La is bonded in a distorted linear geometry to eight equivalent Fe, eight equivalent Ga, and two equivalent C atoms. All La–Fe bond lengths are 3.50 Å. All La–Ga bond lengths are 3.40 Å. Both La–C bond lengths are 2.90 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to eight Fe and four equivalent Ga atoms to form FeGa4Fe8 cuboctahedra that share corners with four equivalent FeLa2Ga4Fe6 cuboctahedra, corners with four equivalent CLa2Fe4 octahedra, and faces with eight equivalent FeLa2Ga4Fe6 cuboctahedra. The corner-sharing octahedral tilt angles are 30°. There are four shorter (2.39 Å) and four longer (2.47 Å) Fe–Fe bond lengths. All Fe–Ga bond lengths are 2.59 Å. In the second Fe site, Fe is bonded in a single-bond geometry to three Fe, four equivalent Ga, and one C atom. Both Fe–Fe bond lengths are 2.54 Å. There are two shorter (2.55 Å) and two longer (2.66 Å) Fe–Ga bond lengths. The Fe–C bond length is 1.85 Å. In the third Fe site, Fe is bonded to two equivalent La, six Fe, and four equivalent Ga atoms to form distorted FeLa2Ga4Fe6 cuboctahedra that share corners with eight FeGa4Fe8 cuboctahedra, corners with two equivalent CLa2Fe4 octahedra, edges with four equivalent FeLa2Ga4Fe6 cuboctahedra, edges with two equivalent CLa2Fe4 octahedra, and faces with seven FeGa4Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 75°. There are two shorter (2.52 Å) and one longer (2.56 Å) Fe–Fe bond lengths. There are a spread of Fe–Ga bond distances ranging from 2.52–2.58 Å. Ga is bonded in a 12-coordinate geometry to two equivalent La, nine Fe, and one Ga atom. The Ga–Ga bond length is 2.84 Å. C is bonded to two equivalent La and four equivalent Fe atoms to form distorted CLa2Fe4 octahedra that share corners with twelve FeLa2Ga4Fe6 cuboctahedra, corners with two equivalent CLa2Fe4 octahedra, and edges with eight equivalent FeLa2Ga4Fe6 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ErTiFe11C by Materials Project

ErTiFe11C crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. Er is bonded in a distorted linear geometry to one Ti, ten Fe, and two equivalent C atoms. The Er–Ti bond length is 3.16 Å. There are a spread of Er–Fe bond distances ranging from 3.06–3.29 Å. Both Er–C bond lengths are 2.42 Å. Ti is bonded in a 1-coordinate geometry to one Er and thirteen Fe atoms. There are a spread of Ti–Fe bond distances ranging from 2.37–2.94 Å. There are six inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are four shorter (2.46 Å) and two longer (2.64 Å) Fe–Fe bond lengths. The Fe–C bond length is 1.89 Å. In the second Fe site, Fe is bonded in a single-bond geometry to two equivalent Ti, six Fe, and one C atom. There are four shorter (2.48 Å) and two longer (2.66 Å) Fe–Fe bond lengths. The Fe–C bond length is 1.90 Å. In the third Fe site, Fe is bonded in a single-bond geometry to one Ti, six Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.44–2.69 Å. The Fe–C bond length is 1.88 Å. In the fourth Fe site, Fe is bonded to two equivalent Er, one Ti, and nine Fe atoms to form distorted FeEr2TiFe9 cuboctahedra that share corners with ten equivalent FeEr2TiFe9 cuboctahedra, corners with two equivalent CEr2Fe4 octahedra, edges with four equivalent FeEr2TiFe9 cuboctahedra, faces with six equivalent FeEr2TiFe9 cuboctahedra, and faces with two equivalent CEr2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 67–69°. There are a spread of Fe–Fe bond distances ranging from 2.42–2.63 Å. In the fifth Fe site, Fe is bonded in a 1-coordinate geometry to one Ti and eight Fe atoms. All Fe–Fe bond lengths are 2.97 Å. In the sixth Fe site, Fe is bonded in a 12-coordinate geometry to one Er, two equivalent Ti, and eleven Fe atoms. The Fe–Fe bond length is 2.43 Å. C is bonded to two equivalent Er and four Fe atoms to form CEr2Fe4 octahedra that share corners with eight equivalent FeEr2TiFe9 cuboctahedra, corners with two equivalent CEr2Fe4 octahedra, and faces with eight equivalent FeEr2TiFe9 cuboctahedra. The corner-sharing octahedral tilt angles are 2°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NdCr2Si2C by Materials Project

NdCr2Si2C crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Nd3+ is bonded in a distorted linear geometry to eight equivalent Si4- and two equivalent C4- atoms. All Nd–Si bond lengths are 3.09 Å. Both Nd–C bond lengths are 2.68 Å. Cr+4.50+ is bonded in a distorted linear geometry to four equivalent Si4- and two equivalent C4- atoms. All Cr–Si bond lengths are 2.45 Å. Both Cr–C bond lengths are 1.99 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Nd3+, four equivalent Cr+4.50+, and one Si4- atom. The Si–Si bond length is 2.50 Å. C4- is bonded to two equivalent Nd3+ and four equivalent Cr+4.50+ atoms to form corner-sharing CNd2Cr4 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ni3Pb2SeS by Materials Project

Ni3Pb2SeS crystallizes in the trigonal R3m space group. The structure is three-dimensional. Ni is bonded in a distorted linear geometry to four Pb, one Se, and one S atom. There are a spread of Ni–Pb bond distances ranging from 2.85–2.88 Å. The Ni–Se bond length is 2.31 Å. The Ni–S bond length is 2.16 Å. There are two inequivalent Pb sites. In the first Pb site, Pb is bonded in a distorted hexagonal planar geometry to six equivalent Ni atoms. In the second Pb site, Pb is bonded to six equivalent Ni, one Se, and one S atom to form distorted corner-sharing PbNi6SeS hexagonal bipyramids. The Pb–Se bond length is 3.17 Å. The Pb–S bond length is 3.22 Å. Se is bonded in a 3-coordinate geometry to three equivalent Ni and one Pb atom. S is bonded in a 3-coordinate geometry to three equivalent Ni and one Pb atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TbTiFe11C by Materials Project

TbTiFe11C crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. Tb is bonded in a distorted linear geometry to one Ti, ten Fe, and two equivalent C atoms. The Tb–Ti bond length is 3.17 Å. There are a spread of Tb–Fe bond distances ranging from 3.07–3.30 Å. Both Tb–C bond lengths are 2.44 Å. Ti is bonded in a 1-coordinate geometry to one Tb and thirteen Fe atoms. There are a spread of Ti–Fe bond distances ranging from 2.36–2.95 Å. There are six inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to six Fe and one C atom. There are four shorter (2.46 Å) and two longer (2.64 Å) Fe–Fe bond lengths. The Fe–C bond length is 1.89 Å. In the second Fe site, Fe is bonded in a single-bond geometry to two equivalent Ti, six Fe, and one C atom. There are four shorter (2.48 Å) and two longer (2.65 Å) Fe–Fe bond lengths. The Fe–C bond length is 1.91 Å. In the third Fe site, Fe is bonded in a single-bond geometry to one Ti, six Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.44–2.71 Å. The Fe–C bond length is 1.89 Å. In the fourth Fe site, Fe is bonded to two equivalent Tb, one Ti, and nine Fe atoms to form distorted FeTb2TiFe9 cuboctahedra that share corners with ten equivalent FeTb2TiFe9 cuboctahedra, corners with two equivalent CTb2Fe4 octahedra, edges with four equivalent FeTb2TiFe9 cuboctahedra, faces with six equivalent FeTb2TiFe9 cuboctahedra, and faces with two equivalent CTb2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 67–69°. There are a spread of Fe–Fe bond distances ranging from 2.43–2.63 Å. In the fifth Fe site, Fe is bonded in a 1-coordinate geometry to one Ti and eight Fe atoms. All Fe–Fe bond lengths are 2.98 Å. In the sixth Fe site, Fe is bonded in a 12-coordinate geometry to one Tb, two equivalent Ti, and eleven Fe atoms. The Fe–Fe bond length is 2.41 Å. C is bonded to two equivalent Tb and four Fe atoms to form CTb2Fe4 octahedra that share corners with eight equivalent FeTb2TiFe9 cuboctahedra, corners with two equivalent CTb2Fe4 octahedra, and faces with eight equivalent FeTb2TiFe9 cuboctahedra. The corner-sharing octahedral tilt angles are 2°.

36 MATERIALS SCIENCE↗
DOE OSTI2022

CEA Contribution to the PIP-II Linear Accelerator

The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018, and will deliver 10 low-beta cryomodules as In-Kind Contribution to the PIP-II project, with cavities supplied by LASA-INFN and power couplers and tuning systems supplied by Fermilab. This paper presents the CEA scope of work that includes the design, manufacturing, assembly and tests of the cryomodules and the upgrade of the existing infrastructures to the PIP-II requirements.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Final Design of the LB650 Cryomodule for the PIP-II Linear Accelerator

The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018, and its scope covers the supply of the 650 MHz low-beta cryomodule section, with the design of the cryostat (i.e the cryomodule without the cavities, the power couplers and the frequency tuning systems) and the manufacturing of its components, the assembly and tests of the pre-production cryomodule and 9 production modules. An important milestone was reached in April 2023 with the Final Design Review. This paper presents the detailed design of the 650 MHz low-beta cryomodules.

43 PARTICLE ACCELERATORS↗
NASA NTRS1992

Single link flexible beam testbed project

This thesis describes the single link flexible beam testbed at the CLaMS laboratory in terms of its hardware, software, and linear model, and presents two controllers, each including a hub angle proportional-derivative (PD) feedback compensator and one augmented by a second static gain full state feedback loop, based upon a synthesized strictly positive real (SPR) output, that increases specific flexible mode pole damping ratios w.r.t the PD only case and hence reduces unwanted residual oscillation effects. Restricting full state feedback gains so as to produce a SPR open loop transfer function ensures that the associated compensator has an infinite gain margin and a phase margin of at least (-90, 90) degrees. Both experimental and simulation data are evaluated in order to compare some different observer performance when applied to the real testbed and to the linear model when uncompensated flexible modes are included.

Hughes, Declan↗
DOE OSTI2024

Parametric reduced-order modeling for component-oriented treatment and localized nonlinear feature inclusion

Abstract We propose coupling a physics-based reduction framework with a suited response decomposition technique to derive a component-oriented reduction (COR) approach, which is suitable for assembly systems featuring localized nonlinearities. Dependencies on influencing parameters are injected into the reduced-order model (ROM), thus ensuring robustness and validity over a domain of parametric inputs, while capturing nonlinear effects. The implemented approach employs individual component modes to capture localized features while additionally relying on reduced modes of a global nature to approximate the system’s dynamics accurately. The global modes are derived from a linear monolithic system, defined as a result of a coordinate separation scheme, which permits the proposed COR-ROM to naturally couple the response between linear and nonlinear subdomains. The derived low-order representation utilizes a proper orthogonal decomposition projection and is additionally reinforced with the inclusion of a hyper-reduction technique to capture the underlying high-fidelity model response while providing accelerated computations. The resulting approach is exemplified in the synthetic case studies of a four-story shear frame with multiple nonlinear regions driven by hysteresis and a large-scale kingpin connection featuring plasticity.

Vlachas, Konstantinos (ORCID:000000029124219X)↗
DOE OSTI2023

Parametric analysis on optimized design of hybrid solar power plants

There is increasing interest in utility-scale solar power plants with storage which can flexibly dispatch renewable energy to the grid. However, plant design possesses many degrees of freedom and non-obvious trade-offs in performance. Software tools can estimate or optimize the performance of a specific plant configuration under market and weather conditions of interest; the associated cost parameters and operating assumptions strongly influence estimates of plant performance and decisions regarding optimal sizing. We employ the National Renewable Energy Laboratory's Hybrid Optimization and Performance Platform, which incorporates optimal dispatch when evaluating plant performance, and investigate the sensitivity to weather and market conditions, operating limitations, and the presence of a capacity-based incentive. We demonstrate changes in plant performance and optimal sizing with respect to these inputs and discuss implications. Here results show that PV-with-battery designs are more profitable under our assumptions, but that designs including a concentrated solar power (CSP) system produce significantly greater annual energy; and that CSP-with-thermal energy storage designs maximizing the benefit-to-cost ratio have an input-dependent linear relationship between the CSP field solar multiple and the hours of storage as the project budget varies.

14 SOLAR ENERGY↗
DOE OSTI2022

Generation and Control of Self-Organized Nonlinear Kinetic Structures in High Energy Density Plasmas in the Presence of Intense Magnetic Fields and Ultrashort Laser Pulses

In the project we investigated mechanisms to sculpt phase space by controlling plasma instabilities. We found that linear theory, which applies in the initial growth phase of an instability, allows for initial conditions that can suppress instabilities. This provides a possible mechanism to release the energy available to an instability on demand. We developed various computational techniques that can reduce computational cost of simulations while maintaining or improving physical fidelity. We considered the Buneman instability in the presence of a ponderomotively driven plasma wave to examine the interplay between an instability and steady-state plasma response.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗