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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

OpenSoC Fabric

Recent advancements in technology scaling have shown a trend towards greater integration with large-scale chips containing thousands of processors connected to memories and other I/O devices using non-trivial network topologies. Software simulation proves insufficient to study the tradeoffs in such complex systems due to slow execution time, whereas hardware RTL development is too time-consuming. We present OpenSoC Fabric, an on-chip network generation infrastructure which aims to provide a parameterizable and powerful on-chip network generator for evaluating future high performance computing architectures based on SoC technology. OpenSoC Fabric leverages a new hardware DSL, Chisel, which contains powerful abstractions provided by its base language, Scala, and generates both software (C++) and hardware (Verilog) models from a single code base. The OpenSoC Fabric2 infrastructure is modeled after existing state-of-the-art simulators, offers large and powerful collections of configuration options, and follows object-oriented design and functional programming to make functionality extension as easy as possible.

Source record↗
DOE OSTI2016

AmeriFlux US-Ro1 Rosemount- G21

This is the AmeriFlux version of the carbon flux data for the site US-Ro1 Rosemount- G21. Site Description - This tower is located in a farm field farmed in accordance with the dominant farming practice in the region: a corn/soybean rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2016

AmeriFlux US-Ro3 Rosemount- G19

This is the AmeriFlux version of the carbon flux data for the site US-Ro3 Rosemount- G19. Site Description - This tower is located in a farm field farmed in accordance with the cominant farming practice in the region: a corn/soybean rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2018

AmeriFlux US-Ro2 Rosemount- C7

This is the AmeriFlux version of the carbon flux data for the site US-Ro2 Rosemount- C7. Site Description - This tower is located in a farm field farmed in accordance with the dominant farming practice in the region: a corn/soybean/clover rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2018

AmeriFlux US-Ro5 Rosemount I18_South

This is the AmeriFlux version of the carbon flux data for the site US-Ro5 Rosemount I18_South. Site Description - This tower is located in a farm field farmed in accordance with the dominant farming practice in the region: a corn/soybean rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2018

AmeriFlux US-Ro6 Rosemount I18_North

This is the AmeriFlux version of the carbon flux data for the site US-Ro6 Rosemount I18_North. Site Description - This tower is located in a farm field farmed in accordance with a conservation type agricultural practice in the region: a corn/soybean/clover (living mulch/cover crop) rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2019

AmeriFlux US-CF2 CAF-LTAR Cook West

This is the AmeriFlux version of the carbon flux data for the site US-CF2 CAF-LTAR Cook West. Site Description - CF2 has operated since May 2017 at the R.J. Cook Agronomy Farm outside of Pullman, Washington, and monitors the conventionally tilled side of a paired-catchment study that is part of the Longterm Agroecosystem Research (LTAR) site common experiment. CF2 is located in “Cook West,” a field that has been in conventional tillage since prior to 1998 and constitutes the Prevalent treatment of the common experiment. In this case, conventional tillage involves chisel plowing after the winter wheat phase of rotations (approximately every 3-4 years) and occasional harrowing. CF2 is paired with the CF1 tower location in “Cook East,” which has been in no-till since 1998 and represents the Alternative treatment of the common experiment. Both fields are planted in the same crops every year. Cook Agronomy Farm is in the high precipitation agroecological zone of the Columbia Plateau’s dryland cropping region. Crop rotations are wheat-based and include winter wheat, spring wheat, chickpea, spring canola, and winter peas. Wheat is the principal cash crop, with other crops grown in rotation for diversity, nutrient, and pest management. Soils are predominantly silt loam texture Mollisols in the Palouse, Thatuna, Naff soil series. The CF2 tower replaced US-RC2, which operated 2012-2016 in a neighboring field that was also conventionally tilled. CF2 and RC2 have distinct footprints, aspects, and soil series compositions.

Huggins, Dave↗
DOE OSTI2021

AmeriFlux FLUXNET-1F US-Ro5 Rosemount I18_South

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-Ro5 Rosemount I18_South. This is the FLUXNET version of the carbon flux data for the site US-Ro5 Rosemount I18_South produced by applying the standard ONEFlux (1F) software. Site Description - This tower is located in a farm field farmed in accordance with the dominant farming practice in the region: a corn/soybean rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2022

AmeriFlux FLUXNET-1F US-CF2 CAF-LTAR Cook West

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-CF2 CAF-LTAR Cook West. This is the FLUXNET version of the carbon flux data for the site US-CF2 CAF-LTAR Cook West produced by applying the standard ONEFlux (1F) software. Site Description - CF2 has operated since May 2017 at the R.J. Cook Agronomy Farm outside of Pullman, Washington, and monitors the conventionally tilled side of a paired-catchment study that is part of the Longterm Agroecosystem Research (LTAR) site common experiment. CF2 is located in “Cook West,” a field that has been in conventional tillage since prior to 1998 and constitutes the Prevalent treatment of the common experiment. In this case, conventional tillage involves chisel plowing after the winter wheat phase of rotations (approximately every 3-4 years) and occasional harrowing. CF2 is paired with the CF1 tower location in “Cook East,” which has been in no-till since 1998 and represents the Alternative treatment of the common experiment. Both fields are planted in the same crops every year. Cook Agronomy Farm is in the high precipitation agroecological zone of the Columbia Plateau’s dryland cropping region. Crop rotations are wheat-based and include winter wheat, spring wheat, chickpea, spring canola, and winter peas. Wheat is the principal cash crop, with other crops grown in rotation for diversity, nutrient, and pest management. Soils are predominantly silt loam texture Mollisols in the Palouse, Thatuna, Naff soil series. The CF2 tower replaced US-RC2, which operated 2012-2016 in a neighboring field that was also conventionally tilled. CF2 and RC2 have distinct footprints, aspects, and soil series compositions.

Huggins, Dave↗
DOE OSTI2022

AmeriFlux FLUXNET-1F US-Ro1 Rosemount- G21

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-Ro1 Rosemount- G21. This is the FLUXNET version of the carbon flux data for the site US-Ro1 Rosemount- G21 produced by applying the standard ONEFlux (1F) software. Site Description - This tower is located in a farm field farmed in accordance with the dominant farming practice in the region: a corn/soybean rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2022

AmeriFlux FLUXNET-1F US-Ro6 Rosemount I18_North

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-Ro6 Rosemount I18_North. This is the FLUXNET version of the carbon flux data for the site US-Ro6 Rosemount I18_North produced by applying the standard ONEFlux (1F) software. Site Description - This tower is located in a farm field farmed in accordance with a conservation type agricultural practice in the region: a corn/soybean/clover (living mulch/cover crop) rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2023

AmeriFlux FLUXNET-1F US-Ro2 Rosemount- C7

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-Ro2 Rosemount- C7. This is the FLUXNET version of the carbon flux data for the site US-Ro2 Rosemount- C7 produced by applying the standard ONEFlux (1F) software. Site Description - This tower is located in a farm field farmed in accordance with the dominant farming practice in the region: a corn/soybean/clover rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2024

AmeriFlux FLUXNET-1F US-Ro3 Rosemount- G19

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-Ro3 Rosemount- G19. This is the FLUXNET version of the carbon flux data for the site US-Ro3 Rosemount- G19 produced by applying the standard ONEFlux (1F) software. Site Description - This tower is located in a farm field farmed in accordance with the cominant farming practice in the region: a corn/soybean rotation with chisel plow tillage in the fall following corn harvest and in the spring following soybeans.

Baker, John↗
DOE OSTI2012

Long-term Differences in Tillage and Land Use Affect Intra-aggregate Pore Heterogeneity

Recent advances in computed tomography provide measurement tools to study internal structures of soil aggregates at micrometer resolutions and to improve our understanding of specific mechanisms of various soil processes. Fractal analysis is one of the data analysis tools that can be helpful in evaluating heterogeneity of the intra-aggregate internal structures. The goal of this study was to examine how long-term tillage and land use differences affect intra-aggregate pore heterogeneity. The specific objectives were: (i) to develop an approach to enhance utility of box-counting fractal dimension in characterizing intra-aggregate pore heterogeneity; (ii) to examine intra-aggregate pores in macro-aggregates (4-6 mm in size) using the computed tomography scanning and fractal analysis, and (iii) to compare heterogeneity of intra-aggregate pore space in aggregates from loamy Alfisol soil subjected to 20 yr of contrasting management practices, namely, conventional tillage (chisel plow) (CT), no-till (NT), and native succession vegetation (NS). Three-dimensional images of the intact aggregates were obtained with a resolution of 14.6 {micro}m at the Advanced Photon Source, Argonne National Laboratory, Argonne, IL. Proposed box-counting fractal dimension normalization was successfully implemented to estimate heterogeneity of pore voxel distributions without bias associated with different porosities in soil aggregates. The aggregates from all three studied treatments had higher porosity associated with large (>100 {micro}m) pores present in their centers than in their exteriors. Pores 15 to 60 {micro}m were equally abundant throughout entire aggregates but their distributions were more heterogeneous in aggregate interiors. The CT aggregates had greater numbers of pores 15 to 60 {micro}m than NT and NS. Distribution of pore voxels belonging to large pores was most heterogeneous in the aggregates from NS, followed by NT and by CT. This result was consistent with presence of very large pores associated with former root channels in NT and NS aggregates. Our findings indicate that mechanisms of macro-aggregate formation might differ in their importance in different land use and management practices.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

FY 2016 Status Report: CIRFT Testing Data Analyses and Updated Curvature Measurements

This report provides a detailed description of FY15 test result corrections/analysis based on the FY16 Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) test program methodology update used to evaluate the vibration integrity of spent nuclear fuel (SNF) under normal transportation conditions. The CIRFT consists of a U-frame testing setup and a real-time curvature measurement method. The three-component U-frame setup of the CIRFT has two rigid arms and linkages to a universal testing machine. The curvature of rod bending is obtained through a three-point deflection measurement method. Three linear variable differential transformers (LVDTs) are used and clamped to the side connecting plates of the U-frame to capture the deformation of the rod. The contact-based measurement, or three-LVDT-based curvature measurement system, on SNF rods has been proven to be quite reliable in CIRFT testing. However, how the LVDT head contacts the SNF rod may have a significant effect on the curvature measurement, depending on the magnitude and direction of rod curvature. It has been demonstrated that the contact/curvature issues can be corrected by using a correction on the sensor spacing. The sensor spacing defines the separation of the three LVDT probes and is a critical quantity in calculating the rod curvature once the deflections are obtained. The sensor spacing correction can be determined by using chisel-type probes. The method has been critically examined this year and has been shown to be difficult to implement in a hot cell environment, and thus cannot be implemented effectively. A correction based on the proposed equivalent gauge-length has the required flexibility and accuracy and can be appropriately used as a correction factor. The correction method based on the equivalent gauge length has been successfully demonstrated in CIRFT data analysis for the dynamic tests conducted on Limerick (LMK) (17 tests), North Anna (NA) (6 tests), and Catawba mixed oxide (MOX) (10 tests) SNF samples. These CIRFT tests were completed in FY14 and FY15. Specifically, the data sets obtained from measurement and monitoring were processed and analyzed. The fatigue life of rods has been characterized in terms of moment, curvature, and equivalent stress and strain..

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

Advanced Scientific Computing Research Exascale Requirements Review. An Office of Science review sponsored by Advanced Scientific Computing Research, September 27-29, 2016, Rockville, Maryland

The widespread use of computing in the American economy would not be possible without a thoughtful, exploratory research and development (R&D) community pushing the performance edge of operating systems, computer languages, and software libraries. These are the tools and building blocks — the hammers, chisels, bricks, and mortar — of the smartphone, the cloud, and the computing services on which we rely. Engineers and scientists need ever-more specialized computing tools to discover new material properties for manufacturing, make energy generation safer and more efficient, and provide insight into the fundamentals of the universe, for example. The research division of the U.S. Department of Energy’s (DOE’s) Office of Advanced Scientific Computing and Research (ASCR Research) ensures that these tools and building blocks are being developed and honed to meet the extreme needs of modern science. See also http://exascaleage.org/ascr/ for additional information.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2017

High Strain Rate Testing of Welded DOP-26 Iridium

The iridium alloy DOP-26 is used to produce Clad Vent Set cups that protect the radioactive fuel in radioisotope thermoelectric generators (RTGs) which provide electric power for spacecraft and rovers. In a previous study, the tensile properties of DOP-26 were measured over a wide range of strain rates and temperatures and reported in ORNL/TM-2007/81. While that study established the properties of the base material, the fabrication of the heat sources requires welding, and the mechanical properties of welded DOP-26 have not been extensively characterized in the past. Therefore, this study was undertaken to determine the mechanical properties of DOP-26 specimens containing a transverse weld in the center of their gage sections. Tensile tests were performed at room temperature, 750, 900, and 1090°C and engineering strain rates of 1×10 -3 and 10 s -1 . Room temperature testing was performed in air, while testing at elevated temperatures was performed in a vacuum better than 1×10 -4 Torr. The welded specimens had a significantly higher yield stress, by up to a factor of ~2, than the non-welded base material. The yield stress did not depend on the strain rate except at 1090°C, where it was slightly higher for the faster strain rate. The ultimate tensile stress, on the other hand, was significantly higher for the faster strain rate at temperatures of 750°C and above. At 750°C and above, the specimens deformed at 1×10 -3 s -1 showed pronounced necking resulting sometimes in perfect chisel-edge fracture. The specimens deformed at 10 s -1 exhibited this fracture behavior only at the highest test temperature, 1090°C. Fracture occurred usually in the fusion zone of the weld and was, in most cases, primarily intergranular.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Holographic Lithography for Industrial Nanomanufacturing

The participant constructed interference lithography experiments on their prototype of a coordinated holographic industrial-scale electromagnetic lithography (CHISEL) tool. These experiments involved generating several laser beams and interfering them in photosensitive materials, whereupon subsequent development resulted in micro- and nano-structured samples. We characterized these samples using scanning electron microscopy and various optical interrogation methods.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗