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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Decreased Electron Transfer between Cr(VI) and AH 2 DS in the Presence of Goethite

9,10‐Anthraquinone‐2,6‐disulfonic acid (AQDS) is commonly used as a model species to examine the influence of quinones on different biogeochemical cycles. The reduced form of this quinone, AH 2 DS, can donate electrons to the toxic metal species Cr(VI), leading to the precipitation of less soluble Cr(III) phases. Due to the environmental abundance of Fe(III) (oxyhydr)oxides, such as goethite (α‐FeOOH), it is important to study the role of these mineral phases on the electron transfer reaction between AH 2 DS and Cr(VI). In this study, this electron transfer reaction is examined in the presence and absence of goethite at three different ratios of AH 2 DS/Cr(VI). Ultraviolet‐visible spectroscopy is used to qualitatively assess the oxidation state of AQDS during reactions with goethite. Iron K‐edge and Cr K‐edge X‐ray absorption spectroscopy are used to examine the role of goethite in electron transfer and identify Cr(III) phases that form. Goethite inhibits the extent of Cr(VI) reduction to Cr(III), most notably at the highest ratio of AH 2 DS/Cr(VI) investigated. Production of semiquinone radical species may limit electron transfer and decrease the yields of Fe(II) and Cr(III), both in the presence and absence of goethite. Understanding abiotic electron transfer reactions that occur in systems with multiple redox active species is important to determine the contribution of abiotic redox reactions to Fe biogeochemical cycling in natural soils. Core Ideas Goethite inhibits the reduction of Cr(VI) to Cr(III) in the presence of AH 2 DS. Semiquinone radical production probably leads to a decrease in reducing equivalents. X‐ray absorption spectroscopy shows no Fe x Cr x (OH) 3 phases form in Cr(VI) reduction.

Tomaszewski, Elizabeth J.↗
DOE OSTI2019

Information Products & Communications Materials for COR and Contractors' Meetings [Slides]

Contents include the following: 1) Large Scale CO 2 Storage in the Lower Tuscaloosa Massive Sand Formation, December 12, 2007; 2) CoalFleet Program Update and Workshops, July 26-28, 2005; 3) Regional Carbon Sequestration Partnership Annual Review Meeting, November 18, 2009; 4) SECARB U. S. Regional Partnerships from Pilot to Demonstration, November 5, 2009; 5) The SECARB Anthropogenic Test–CO 2 Capture/Transportation/Storage, August 21-23, 2012; 6) Citronelle Project–Experiences With Permitting and Regulations on CCS, August 21, 2013; 7) Partnering With Industry for Large Scale CCS Projects, August 22, 2013; 8) Plant Barry-Citronelle Field Project, August 13, 2104; 9) SECARB's Early Test at Cranfield, Mississippi; 10) SECARB Partnership Early Test at Cranfield Status, August 18-20, 2015; 11) Citronelle Project, August 18, 2015; 12) Plant Barry 25 MW Demo; 13) SECARB Phase III Citronelle Project (Anthropogenic Test) in Alabama, August 18, 2015; 14) SECARB Early Test Retrospective; 15) SECARB Anthropogenic Test Lessons Learned, August 16-18, 2016; 16) SECARB Early Test at Cranfield, August 1-3, 2017; 17) Carbon Storage and Oil and Natural Gas Technologies Review Meeting, August 1-3, 2017; 18) SECARB Partnership Early Test at Cranfield, August 13-16, 2018; 19) SECARB Anthropogenic Test Update, August 13-16, 2018; 20) SECARB Partnership Early Test at Cranfield, August 26-30, 2019; 21) SECARB (Citronelle) Phase III, August 27, 2019.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2018

Polarized neutron scattering study of the multiple order parameter system NdB 4 [Polarized neutron scattering study on multiple order parameter system NdB 4 ]

Neutron polarization analysis has been carried out in order to clarify the magnetic structures of multiple order parameter f-electron system NdB 4 . We confirmed the noncollinear “all-in all-out” structure (Γ 4 ) of the in-plane moment, which is in good agreement with our previous neutron powder diffraction study. We found that the magnetic moment along the c-axis m c showed diagonally antiferromagnetic structure (Γ 10 ), inconsistent with previously reported “vortex” structure (Γ 2 ). The microscopic mixture of these two structures with → q 0 =(0,0,0) appears in phase II and remains stable in phases III and IV, where an incommensurate modulation coexists. The unusual magnetic ordering is phenomenologically understood via Landau theory with the primary order parameter Γ 4 coupled with higher-order secondary order parameter Γ 10 . The magnetic moments were estimated to be 1.8 ± 0.2 and 0.2 ± 0.05μ B at T = 7.5K for Γ 4 and Γ 10 , respectively. We also found a long-period incommensurate modulation of the → q 1 =(0,0,1/2) antiferromagnetic structure of mc with the propagation → q s1 =(0.14,0.14,0.1) and → q s2 =(0.2,0,0.1) in phase III and IV, respectively. The amplitude of sinusoidal modulation was about m c =1.0 ± 0.2μ B at T=1.5 K. The local (0,0,1/2) structure consists of in-plane ferromagnetic and out-of-plane antiferromagnetic coupling of m c , opposite to the coexisting Γ 10 . The mc of Γ 10 is significantly enhanced up to 0.6μ B at T=1.5 K, which is accompanied by the incommensurate modulations. As a result, the Landau phenomenological approach indicates that the higher-order magnetic and/or multipole interactions based on the pseudoquartet f-electron state play important roles.

36 MATERIALS SCIENCE↗
NASA NTRS2007

A Microfabricated Involute-Foil Regenerator for Stirling Engines

A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmented-involute-foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM (electric discharge machining). During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil disks was tested in an oscillating-flow test rig. These test results yielded a performance figure of merit (roughly the ratio of heat transfer to pressure drop) of about twice that of the 90% random fiber currently used in small ~ 100 W Stirling space-power convertors in the Reynolds Number range of interest (50-100). A Phase III effort is now underway to fabricate and test a segmented-involute-foil regenerator in a Stirling convertor. Though funding limitations prevent optimization of the Stirling engine geometry for use with this regenerator, the Sage computer code will be used to help evaluate the engine test results. Previous Sage Stirling model projections have indicated that a segmented-involute-foil regenerator is capable of improving the performance of an optimized involute-foil engine by 6-9%; it is also anticipated that such involute-foil geometries will be more reliable and easier to manufacture with tight-tolerance characteristics, than random-fiber or wire-screen regenerators. Beyond the near-term Phase III regenerator fabrication and engine testing, other goals are (1) fabrication from a material suitable for high temperature Stirling operation (up to 850 C for current engines; up to 1200 C for a potential engine-cooler for a Venus mission), and (2) reduction of the cost of the fabrication process to make it more suitable for terrestrial applications of segmented involute foils. Past attempts have been made to use wrapped foils to approximate the large theoretical figures of merit projected for parallel plates. Such metal wrapped foils have never proved very successful, apparently due to the difficulties of fabricating wrapped-foils with uniform gaps and maintaining the gaps under the stress of time-varying temperature gradients during start-up and shut-down, and relatively-steady temperature gradients during normal operation. In contrast, stacks of involute-foil disks, with each disk consisting of multiple involute-foil segments held between concentric circular ribs, have relatively robust structures. The oscillating-flow rig tests of the segmented-involute-foil regenerator have demonstrated a shift in regenerator performance strongly in the direction of the theoretical performance of ideal parallel-plate regenerators.

Tew, Roy↗
NASA NTRS2007

A Microfabricated Involute-Foil Regenerator for Stirling Engines

A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmented-involute-foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM. During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil disks was tested in an oscillating-flow test rig. These test results yielded a performance figure of merit (roughly the ratio of heat transfer to pressure drop) of about twice that of the 90 percent random fiber currently used in small approx.100 W Stirling space-power convertors-in the Reynolds Number range of interest (50 to 100). A Phase III effort is now underway to fabricate and test a segmented-involute-foil regenerator in a Stirling convertor. Though funding limitations prevent optimization of the Stirling engine geometry for use with this regenerator, the Sage computer code will be used to help evaluate the engine test results. Previous Sage Stirling model projections have indicated that a segmented-involute-foil regenerator is capable of improving the performance of an optimized involute-foil engine by 6 to 9 percent; it is also anticipated that such involute-foil geometries will be more reliable and easier to manufacture with tight-tolerance characteristics, than random-fiber or wire-screen regenerators. Beyond the near-term Phase III regenerator fabrication and engine testing, other goals are (1) fabrication from a material suitable for high temperature Stirling operation (up to 850 C for current engines; up to 1200 C for a potential engine-cooler for a Venus mission), and (2) reduction of the cost of the fabrication process to make it more suitable for terrestrial applications of segmented involute foils. Past attempts have been made to use wrapped foils to approximate the large theoretical figures of merit projected for parallel plates. Such metal wrapped foils have never proved very successful, apparently due to the difficulties of fabricating wrapped-foils with uniform gaps and maintaining the gaps under the stress of time-varying temperature gradients during start-up and shut-down, and relatively-steady temperature gradients during normal operation. In contrast, stacks of involute-foil disks, with each disk consisting of multiple involute-foil segments held between concentric circular ribs, have relatively robust structures. The oscillating-flow rig tests of the segmented-involute-foil regenerator have demonstrated a shift in regenerator performance strongly in the direction of the theoretical performance of ideal parallel-plate regenerators.

Tew, Roy↗
DOE OSTI2020

Enhanced Recovery Opportunities in the Appalachian Basin

The Midwest Regional Carbon Sequestration Partnership (MRCSP) has incorporated the work of geologic research teams (Geoteams) in its regional characterization, project planning and carbon dioxide (CO2) injection implementation work since the partnership was established by the U.S. Department of Energy (DOE) in 2003. Over this 16-year period, the cohort of Geoteams has grown from five to ten states and has contributed to the characterization of geologic sequestration opportunities, refinement of reservoir and seal data, and supported injection efforts through both predictive and post-injection assessments. The regional characterization work conducted by the Geoteams during the MRCSP Phase III project period (2010 – 2019) focused on the following tasks: (1) refinement of geologic seals/reservoir systems; (2) assessment of Atlantic Coastal Plain and offshore opportunities; (3) expanded assessments of oil and gas fields, particularly as they relate to enhanced recovery opportunities; (4) regional support for implementation of carbon capture utilization and storage (CCUS) in the partnership area; and (5) communication and data sharing. The findings of this work are summarized in the final report entitled Final Report of Geologic Carbon Capture Utilization and Storage Opportunities in the form of a state-by-state presentation for the MRCSP Region. In addition to the capstone deliverable mentioned above, the Geoteams have also prepared a series of topical reports to elaborate on specific geologic intervals and/or geographic areas of study completed during the Phase III project period. Specifically, these topical reports address: (1) the Atlantic Coastal Plain and adjacent offshore; (2) Cambro-Ordovician reservoirs/seals in the region; (3) enhanced oil and gas recovery opportunities in the Appalachian Basin; and (4) enhanced oil recovery (EOR) in the Michigan Basin. The remainder of this topical report presents our findings relative to enhanced recovery opportunities in the Appalachian Basin.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Reliable, Practical Kilowatt-class Cryogenics for Superconducting Devices

Following the successful development of a Flexibly-Attached Remote cryocooler for ~200W at 80K under a Phase II DOE grant, Clever Fellows Innovation Consortium, Inc. (dba CFIC-Qdrive; acquired by Chart Industries in 2012) was invited by the DOE to scale up this technology to ~1000W/80K in a Phase III program. This target is responsive to the “Cryogenics Roadmap” developed by the DOE to accelerate the development of cryogenic cooling necessary to support the emerging superconducting power applications. Mirroring the Roadmap, our proposal included a capacity target (1000W at 80K) and a cost target (<$40/watt, at 80K), but unlike the Roadmap, we did not formally propose to meet a specific efficiency target. We achieved 75% of the capacity target, with a record-size coaxial “pulse-tube” coldfinger, but only by working on the project well beyond the original “period of performance” on unfunded extension. We believe 100% of the capacity target was within reach, but our own budget and time constraints forbade additional effort. We were less successful in meeting the cost targets. Ultimately, the specific configuration that was the subject of Phase III was not commercialized, largely because the market for superconducting devices has not been nearly as robust as was expected at the advent of the Roadmap.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2019

Guided Optimization of Phase-Unstable III–V Compositionally Graded Buffers by Cathodoluminescence Spectrum Imaging

Compositionally graded buffers (CGBs) are essential components of high-efficiency III-V inverted metamorphic solar cells, and high-quality CGBs with low defect densities are a requirement for high device efficiencies. Here, we use plan-view and cross-sectional cathodoluminescence spectrum imaging (CLSI) to investigate the effect of growth conditions on the microstructure of Al y Ga 1-x-y In x AS CGBs with x In > 0.30. CLSI reveals significant compositional fluctuation in these materials that correlates with the distribution of threading dislocations in the CGBs. Threading dislocations are observed to collect in regions between abrupt transitions in emission energy, implying that concomitant strain fluctuations in these regions restrict dislocation motion. Thus, the compositional fluctuation leads to elevated threading dislocation densities that degrade CGB quality. We also correlate compositional fluctuation in the CGB with compositional fluctuation in subsequently grown device layers. The effectiveness of specific growth conditions at suppressing compositional fluctuation and limiting threading dislocation density is evaluated. CGBs grown at high temperatures with high Al content exhibit the lowest defect densities. The use of a high V/III ratio suppresses compositional fluctuation and defect density. In conclusion, these insights lead directly to improvements in the efficiency of metamorphic Ga 1-x In x As solar cells grown on AlyGa 1-x-y In x As CGBs.

14 SOLAR ENERGY↗
NASA NTRS2007

The ASPRS Remote Sensing Industry Forecast: Phase II & III - Digital Sensor Compilation

In August 1999, ASPRS and NASA's (then) Commercial Remote Sensing Program (CRSP) entered into a 5-year Space Act Agreement (SAA), combining resources and expertise to: (a) Baseline the Remote Sensing Industry (RSI) based on GEIA Model; (b) Develop a 10-Year RSI market forecast and attendant processes; and (c) Provide improved information for decision makers.

Mondello, Charles↗
NASA NTRS2021

Long-Duration Wear Testing of the ASTRAEUS Hall Thruster, Phases II & III: 72 kg Xe Throughput & 1.2 MN-s Total Impulse

The thruster component of the Ascendant Sub-kW Transcelestial Electric Propulsion System successfully completed a propellant throughput demonstration of 72 kg Xe in a long-duration wear test planned to eventually exceed 100 kg. The thruster has been operated for a total of 5450 h over three operating conditions: 3287 h at 300 V – 1000 W, 1745 h at 500 V – 1000 W, and 417 h at 400 V – 600 W. A total of 1.2 MN-s of impulse has been demonstrated to date. Thrust, telemetry, and temperature measurements periodically recorded at four operating conditions spanning 200 – 500 V and 200 – 1000 W revealed constant performance across the full test duration. The erosion of the downstream faces of the thruster was observed to be higher than anticipated after the first 5032 h of thruster operation. This issue was traced to the application of sub-nominal magnetic field strengths throughout the LDWT, caused by an electrical-related ground-support equipment issue, which resulted in a downstream shift of the discharge plasma and enhanced erosion of the thruster’s pole covers. Nevertheless, the thruster performance and operational behaviour remained unaffected. High-fidelity plasma simulations of the erosion of the thruster’s downstream faces, supported by prior short-duration wear testing, suggest a theoretical lifetime capability of >30 kh, corresponding to propellant throughput of >450 kg Xe and a total impulse of >7 MNs, at the 300 V – 1000 W operating condition. The test was voluntarily paused after 68 kg Xe and 72 kg Xe throughput, respectively, to take these erosion measurements at the 500 V and 400 V operating conditions before the test was resumed at a different operating condition.

Goebel, Dan↗
DOE OSTI2024

Analysis of Automated Transit Network Systems with Battery-Electric Vehicles in Automated Mobility Districts: Preprint

The paper provides an overview of the insights and findings of the National Renewable Energy Laboratory's (NREL) ongoing research on the implementation of automated mobility districts (AMDs). AMD is a term coined by NREL to describe a geographically defined district or major activity center located in a dense urban setting with mobility applications provided by automated/autonomous vehicle (AV) systems spanning internal circulation and first-mile/last-mile connections to regional transportation hubs. Research over the past five years has focused on understanding the evolution of AMDs, beginning with demonstrations of automated shuttles prior to the pandemic, to more integrated on-demand mobility systems currently in initial stages of deployment. Initial insights and findings from earlier studies include the need for designation of a "jurisdiction having authority," a clear vision of a complete system to provide end-to-end mobility services, and the requisite intelligent infrastructure to complement AV technology. NREL's most recent Phase III research investigates station boarding/alighting (curb) issues, the full electrification of fleets, and the need for a systems engineering methodology (SEM) to properly analyze the complexities resulting from the convergence of automation, on-demand mobility, and electrification of the transit systems within the AMD. The paper reviews the findings of AMD research conducted during Phase I, II, and III, with special emphasis on Phase III results with respect to a descriptive example of the proposed SEM when a "digital twin" analytical model is used to simulate the transport fleet's battery-electric vehicle miles of travel and associated duty cycles through a rigorous analytical assessment with a comprehensive modeling process.

ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2018

The grain refinement mechanisms of various phases in shot-peened Nickel-Aluminum bronze (NAB) alloy

Highlights: • There exist two grain refinement mechanisms at the same time in the α phase. • The refinement of β' phase is attributed to the formation of dense and ordered nano twins. • The brittle strip-shape κ{sub iii} phases are fragmented after large deformation. • The κ{sub iv} and κ{sub ii} phases exhibit the twinning and dislocation deformation modes, separately. • The microhardness increases significantly owing to work hardening effect and grain refinement. - Abstract: In this study, coarse-grained Nickel-Aluminum bronze (NAB) alloy is subjected to shot-peening (SP) treatment, and the grain refinement mechanisms of various phases in shot-peened NAB alloy are investigated separately. The results show that severe deformation layers are produced on the surface. Meanwhile, refined grains with the average size below 100 nm are induced through SP treatment indicated by the results of X-ray diffraction (XRD) patterns. Various phases in NAB alloy including α, β' and three intermetallic phases (κ{sub ii}, κ{sub iii} and κ{sub iv}) display different grain refinement mechanisms. The grain refinement in the α phase involves dislocation segmentation in the precipitation-free zone and the twinning intersection in the precipitation zone. The formation of nanotwins by emitting partial dislocations at the grain boundary is found to be responsible for the grain refinement in the β' phase. As for the κ phases, the strip-shaped κ{sub iii} phases are fragmented after severe deformation, and the κ{sub iv} and κ{sub ii} phases exhibit the twinning and dislocation deformation modes, respectively. Also, the microhardness is significantly enhanced after SP treatment, which is mainly attributed to the work hardening effect and grain refinement.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Dense Carbon Monoxide to 160 GPa: Stepwise Polymerization to Two-Dimensional Layered Solid

Carbon monoxide (CO) is the first molecular system found to transform into a nonmolecular “polymeric” solid above 5.5 GPa, yet been studied beyond 10 GPa. Here, we show a series of pressure-induced phase transformations in CO to 160 GPa: from a molecular solid to a highly colored, low-density polymeric phase I to translucent, high-density phase II to transparent, layered phase III. The properties of these phases are consistent with those expected from recently predicted 1D P2 1 /m, 3D I2 1 2 1 2 1 , and 2D Cmcm structures, respectively. Furthermore, the present results advocate a stepwise polymerization of CO triple bonds to ultimately a 2D singly bonded layer structure with an enhanced ionic character.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Structural connection between gallium crystals and near- T m liquids under ambient pressure

We study the short-range structural order in liquid gallium prepared by ab initio molecular dynamics simulations. We found that at 400 K, which is close to the melting point (Tm) of Ga, the dominant motif in the liquid phase is identical to that in the stable solid phase Ga-I. Strong directional bonding in this motif prevents it from nucleation in the liquid phase. Meanwhile, a newly identified motif, topologically distinct from yet related to those in β-Ga and Ga-III phases, is also abundant in Ga liquid. This new motif could serve as precursors for β-Ga or Ga-III during crystallization.

Zhang, F.↗