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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 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Winter 2016 Progress Update: Better Buildings Alliance

From 2013-2016, the Better Buildings Alliance published an update each winter on the previous year's activities, including partner projects, sector priorities, technology teams, and market solutions efforts. This report covers activities from calendar year 2015. It is also the final report, as going forward the Better Buildings Alliance activities were included in the annual Better Buildings Progress Report.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

Partnering for the Future: Leadership, Innovation, and Proven Solutions (Progress Report 2021)

This annual report from the Better Buildings Initiative contains information about partner projects, energy and cost savings, and new program initiatives. The 2021 Progress Report also recognizes the latest group of Better Buildings Goal Achievers - organizations who have met their energy, water, and/or financing commitments under the Better Buildings or Better Plants Challenge.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2022

Stepping Up to the Challenge Together (Progress Report, 2022)

This annual report from the Better Buildings Initiative contains information about partner projects, energy and cost savings, and new program initiatives. The 2022 Progress Report also recognizes the latest group of Better Buildings Goal Achievers - organizations who have met their energy, water, and/or financing commitments under the Better Buildings or Better Plants Challenge.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2022

Routing Problem for Unmanned Aerial Vehicle Patrolling Missions - A Progressive Hedging Algorithm

This paper presents a two-stage stochastic program to model a routing problem involving an Unmanned Aerial Vehicle (UAV) in the context of patrolling missions. In particular, given a set of targets and a set of supplemental targets corresponding to each target, the first stage decisions involve finding the sequence in which the vehicle has to visit the set of targets. Upon reaching each target, the UAV collects information and if the operator of the UAV deems that the information collected is not of sufficient fidelity, then the UAV has to visit all the supplemental targets corresponding to that target to collect additional information before proceeding to visit the next target. The problem is solved using a progressive hedging algorithm and extensive computational results corroborating the effectiveness of the proposed model and the solution methodology is presented.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2016

BBPH: Using progressive hedging within branch and bound to solve multi-stage stochastic mixed integer programs

Progressive hedging, though an effective heuristic for solving stochastic mixed integer programs (SMIPs), is not guaranteed to converge in this case. Here, we describe BBPH, a branch and bound algorithm that uses PH at each node in the search tree such that, given sufficient time, it will always converge to a globally optimal solution. Additionally, to providing a theoretically convergent “wrapper” for PH applied to SMIPs, computational results demonstrate that for some difficult problem instances branch and bound can find improved solutions after exploring only a few nodes.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2024

Spatial Progression of Polysulfide Reactivity with Lithium Nitrate in Li–Sulfur Batteries

LiNO 3 is a commonly used electrolyte additive in Li-S batteries, but the intricacies of its stabilizing effect on these batteries are not well-understood due to the complex chemical nature of Li-S electrolytes. This complexity often hampers clear characterization and interpretation of data. In this study, we explore the reactivity of LiNO 3 in Li-S batteries through in operando sulfur K-edge spectroscopy. To remove ambiguities, a sulfur-free electrolyte with LiNO 3 as the sole salt is used. This allows a precise elucidation of the reaction mechanism between LiNO 3 and polysulfides. Here, we observe that the reaction is chemical in nature and progresses spatially, influenced by the polysulfide concentration gradient across the electrolyte. Polysulfides are electrochemically generated in situ on the cathode side, leading to high local concentration. As a result, they cannot be fully oxidized by LiNO 3 and forms sulfites initially which are gradually further oxidized into sulfonates and sulfates. Conversely, polysulfides on the anode side have lower local concentration as they are not generated in situ but diffused from the cathode side. Their reaction with LiNO 3 leads to highly oxidized species like sulfonates and sulfates. These reaction products are not reduced during electrochemically cycling, suggesting their capabilities of passivating the electrodes and contributing to the cycle stabilities of Li-S batteries.

25 ENERGY STORAGE↗
DOE OSTI2014

Lunar occultation observation of μ Sgr: A progress report

Lunar Occultation (LO) is an event where limb of the Moon passing over a particular heavenly bodies such as stars, asteroids, or planets. In other words, during the event, stars, asteroids and planets are occulted by the Moon. When occulted objects contact the lunar limb, there will be a diffraction fringe(s) which can be measured photometrically, until the signal vanishes into noise. This event will give us a valuable information about binarities (of stars) and/or angular diameters estimation (of stars, planets, asteroids) in milliarcsecond resolution, by fitting with theoretical LO pattern. CCDs are common for LO observation because of its fast read out, and recently are developed for sub-meter class telescope. In this paper, our LO observation attempt of μ Sgr and its progress report are presented. The observation was conducted on July 30{sup th}, 2012 at Bosscha Observatory, Indonesia, using 45cm f/12 GOTO telescope combined with ST-9 XE CCD camera and Bessel B filter. We used drift-scan method to obtain light curve of the star as it was disappearing behind Moon's dark limb. Our goal is to detect binarity (or multiplicity) of this particular object.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

SIRIUS: Enabling Progressive Data Exploration for Extreme-Scale Scientific Data

Scientific simulations on high performance computing (HPC) platforms generate large quantities of data. To bridge the widening gap between compute and I/O, and enable data to be more efficiently stored and analyzed, simulation outputs need to be refactored, reduced, and appropriately mapped to storage tiers. However, a systematic solution to support these steps has been lacking in the current HPC software ecosystem. To that end, this paper develops SIRIUS, a progressive JPEG-like data management scheme for storing and analyzing big scientific data. It co-designs data decimation, compression, and data storage, taking the hardware characteristics of each storage tier into considerations. With reasonably low overhead, our approach refactors simulation data, using either topological or uniform decimation, into a much smaller, reduced-accuracy base dataset, and a series of deltas that is used to augment the accuracy if needed. The base dataset and deltas are compressed and written to multiple storage tiers. Data saved on different tiers can then be selectively retrieved to restore the level of accuracy that satisfies data analytics. Thus, SIRIUS provides a paradigm shift towards elastic data analytics and enables end users to make trade-offs between analysis speed and accuracy on-the-fly. This paper further develops algorithms to preserve statistics for data decimation, a common requirement for reducing data. Here, we assess the impact of SIRIUS on unstructured triangular meshes, a pervasive data model used in scientific simulations. In particular, we evaluate two realistic use cases: the blob detection in fusion and high-pressure area extraction in computational fluid dynamics.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2023

Progressive Tree-Based Compression of Large-Scale Particle Data

Scientific simulations and observations using particles have been creating large datasets that require effective and efficient data reduction to store, transfer, and analyze. However, current approaches either compress only small data well while being inefficient for large data, or handle large data but with insufficient compression. Toward effective and scalable compression/decompression of particle positions, we introduce new kinds of particle hierarchies and corresponding traversal orders that quickly reduce reconstruction error while being fast and low in memory footprint. Our solution to compression of large-scale particle data is a flexible block-based hierarchy that supports progressive, random-access, and error-driven decoding, where error estimation heuristics can be supplied by the user. For low-level node encoding, we introduce new schemes that effectively compress both uniform and densely structured particle distributions. Our proposed methods thus target all three phases of a tree-based particle compression pipeline, namely tree construction, tree traversal, and node encoding. In conclusion, the improved efficacy and flexibility of these methods over existing compressors are demonstrated through extensive experimentation, using a wide range of scientific particle datasets.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2011

2011 Annual Progress Report: DOE Hydrogen and Fuel Cells Program (Book)

In the past year, the DOE Hydrogen and Fuel Cells Program (the Program) made substantial progress toward its goals and objectives. The Program has conducted comprehensive and focused efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. With emphasis on applications that will effectively strengthen our nation's energy securityand improve our stewardship of the environment, the Program engages in research, development, and demonstration of critical improvements in the technologies. Highlights of the Program's accomplishments can be found in the sub-program chapters of this report.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2011

Computational mechanics research and support for aerodynamics and hydraulics at TFHRC, year 1 quarter 3 progress report.

The computational fluid dynamics (CFD) and computational structural mechanics (CSM) focus areas at Argonne's Transportation Research and Analysis Computing Center (TRACC) initiated a project to support and compliment the experimental programs at the Turner-Fairbank Highway Research Center (TFHRC) with high performance computing based analysis capabilities in August 2010. The project was established with a new interagency agreement between the Department of Energy and the Department of Transportation to provide collaborative research, development, and benchmarking of advanced three-dimensional computational mechanics analysis methods to the aerodynamics and hydraulics laboratories at TFHRC for a period of five years, beginning in October 2010. The analysis methods employ well-benchmarked and supported commercial computational mechanics software. Computational mechanics encompasses the areas of Computational Fluid Dynamics (CFD), Computational Wind Engineering (CWE), Computational Structural Mechanics (CSM), and Computational Multiphysics Mechanics (CMM) applied in Fluid-Structure Interaction (FSI) problems. The major areas of focus of the project are wind and water loads on bridges - superstructure, deck, cables, and substructure (including soil), primarily during storms and flood events - and the risks that these loads pose to structural failure. For flood events at bridges, another major focus of the work is assessment of the risk to bridges caused by scour of stream and riverbed material away from the foundations of a bridge. Other areas of current research include modeling of flow through culverts to assess them for fish passage, modeling of the salt spray transport into bridge girders to address suitability of using weathering steel in bridges, vehicle stability under high wind loading, and the use of electromagnetic shock absorbers to improve vehicle stability under high wind conditions. This quarterly report documents technical progress on the project tasks for the period of April through June 2011.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Computational mechanics research and support for aerodynamics and hydraulics at TFHRC year 1 quarter 4 progress report.

The computational fluid dynamics (CFD) and computational structural mechanics (CSM) focus areas at Argonne's Transportation Research and Analysis Computing Center (TRACC) initiated a project to support and compliment the experimental programs at the Turner-Fairbank Highway Research Center (TFHRC) with high performance computing based analysis capabilities in August 2010. The project was established with a new interagency agreement between the Department of Energy and the Department of Transportation to provide collaborative research, development, and benchmarking of advanced three-dimensional computational mechanics analysis methods to the aerodynamics and hydraulics laboratories at TFHRC for a period of five years, beginning in October 2010. The analysis methods employ well-benchmarked and supported commercial computational mechanics software. Computational mechanics encompasses the areas of Computational Fluid Dynamics (CFD), Computational Wind Engineering (CWE), Computational Structural Mechanics (CSM), and Computational Multiphysics Mechanics (CMM) applied in Fluid-Structure Interaction (FSI) problems. The major areas of focus of the project are wind and water effects on bridges - superstructure, deck, cables, and substructure (including soil), primarily during storms and flood events - and the risks that these loads pose to structural failure. For flood events at bridges, another major focus of the work is assessment of the risk to bridges caused by scour of stream and riverbed material away from the foundations of a bridge. Other areas of current research include modeling of flow through culverts to assess them for fish passage, modeling of the salt spray transport into bridge girders to address suitability of using weathering steel in bridges, CFD analysis of the operation of the wind tunnel in the TFCHR wind engineering laboratory, vehicle stability under high wind loading, and the use of electromagnetic shock absorbers to improve vehicle stability under high wind conditions. This quarterly report documents technical progress on the project tasks for the period of July through September 2011.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Super B Progress Report for Accelerator

This report details the progress made in by the SuperB Project in the area of the Collider since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

43 PARTICLE ACCELERATORS↗
DOE OSTI2011

Progress Report for Diffusion Welding of the NGNP Process Application Heat Exchangers (Revision 1)

The U.S. Department of Energy selected the high temperature gas-cooled reactor as the basis for the Next Generation Nuclear Plant (NGNP). The NGNP will demonstrate the use of nuclear power for electricity, hydrogen production, and process heat applications. The NGNP Project is currently investigating the use of metallic, diffusion welded, compact heat exchangers to transfer heat from the primary (reactor side) heat transport system to the secondary heat transport system. An intermediate heat exchanger will transfer this heat to downstream applications such as hydrogen production, process heat, and electricity generation. The channeled plates that make up the heat transfer surfaces of the intermediate heat exchanger will have to be assembled into an array by diffusion welding. This report describes the preliminary results of a scoping study that evaluated the diffusion welding process parameters and the resultant mechanical properties of diffusion welded joints using Alloy 800H. The long-term goal of the program is to progress towards demonstration of small heat exchanger unit cells fabricated with diffusion welds. Demonstration through mechanical testing of the unit cells will support American Society of Mechanical Engineers rules and standards development, reduce technical risk, and provide proof of concept for heat exchanger fabrication methods needed to deploy heat exchangers in several potential NGNP configurations.1 Researchers also evaluated the usefulness of modern thermodynamic and diffusion computational tools (Thermo-Calc and Dictra) in optimizing the parameters for diffusion welding of Alloy 800H. The modeling efforts suggested a temperature of 1150°C for 1 hour with an applied pressure of 5 MPa using 15 μm nickel foil as joint filler to reduce chromium oxidation on the welded surfaces. Good agreement between modeled and experimentally determined concentration gradients was achieved

08 HYDROGEN↗
DOE OSTI2012

Ultrascale Visualization Climate Data Analysis Tools (UV-CDAT): Semi-Annual Progress Report

This report summarizes work carried out by the Ultrascale Visualization Climate Data Analysis Tools (UV-CDAT) Team for the period of July 1, 2011 through December 31, 2011. It discusses highlights, overall progress, period goals, and collaborations and lists papers and presentations. The UV-CDAT team is positioned to address the following high-level visualization requirements: (1) Alternative parallel streaming statistics and analysis pipelines - Data parallelism, Task parallelism, Visualization parallelism; (2) Optimized parallel input/output (I/O); (3) Remote interactive execution; (4) Advanced intercomparison visualization; (5) Data provenance processing and capture; and (6) Interfaces for scientists - Workflow data analysis and visualization construction tools, Visualization interfaces.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2012

High-Efficiency Low-Cost Thin-Film GaAs Photovoltaic Module Development Program: July 14, 2010 - January 13, 2012 (Final Technical Progress Report)

This is the final technical progress report of the High-Efficiency Low-Cost Thin-Film GaAs Photovoltaic Module Development Program. Alta Devices has successfully completed all milestones and deliverables established as part of the NREL PV incubator program. During the 18 months of this program, Alta has proven all key processes required to commercialize its solar module product. The incubatorfocus was on back end process steps directed at conversion of Alta's high quality solar film into high efficiency 1-sun PV modules. This report describes all program deliverables and the work behind each accomplishment.

14 SOLAR ENERGY↗
DOE OSTI2012

Computational Mechanics Research and Support for Aerodynamics and Hydraulics at TFHRC: Year 2 Quarter 1 Progress Report

The computational fluid dynamics (CFD) and computational structural mechanics (CSM) focus areas at Argonne's Transportation Research and Analysis Computing Center (TRACC) initiated a project to support and compliment the experimental programs at the Turner-Fairbank Highway Research Center (TFHRC) with high performance computing based analysis capabilities in August 2010. The project was established with a new interagency agreement between the Department of Energy and the Department of Transportation to provide collaborative research, development, and benchmarking of advanced three-dimensional computational mechanics analysis methods to the aerodynamics and hydraulics laboratories at TFHRC for a period of five years, beginning in October 2010. The analysis methods employ well-benchmarked and supported commercial computational mechanics software. Computational mechanics encompasses the areas of Computational Fluid Dynamics (CFD), Computational Wind Engineering (CWE), Computational Structural Mechanics (CSM), and Computational Multiphysics Mechanics (CMM) applied in Fluid-Structure Interaction (FSI) problems. The major areas of focus of the project are wind and water effects on bridges - superstructure, deck, cables, and substructure (including soil), primarily during storms and flood events - and the risks that these loads pose to structural failure. For flood events at bridges, another major focus of the work is assessment of the risk to bridges caused by scour of stream and riverbed material away from the foundations of a bridge. Other areas of current research include modeling of flow through culverts to improve design allowing for fish passage, modeling of the salt spray transport into bridge girders to address suitability of using weathering steel in bridges, CFD analysis of the operation of the wind tunnel in the TFHRC wind engineering laboratory. This quarterly report documents technical progress on the project tasks for the period of October through December 2011.

36 MATERIALS SCIENCE↗
DOE OSTI2012

The Science and Engineering of Durable Ultralow PGM Catalysts (2012 DOE-EERE-FCT Annual Progress Report)

Minimizing the quantity of Pt group metals used in polymer membrane fuel cells (PEMFCs) is one of the remaining grand challenges for fuel cell commercialization. Tremendous progress has been achieved over the last two decades in decreasing the Pt loading required for efficient fuel cell performance. Unfortunately, the fluctuations in the price of Pt represent a substantial barrier to the economics of widespread fuel cell use. Durability and impurity tolerance are also challenges that are tightly coupled to fuel cell Pt electrode loading. Traditional approaches to decreasing the amount of Pt required for good performance include: (1) Increasing mass activity by decreasing Pt particle size by supporting on carbon; (2) Alloy formulation Pt-Co, Pt-Cr alloys to improve mass activity; (3) Increasing Pt utilization by optimization of electronic and ionic contact of the Pt particles; (4) Improving conductivity of the electronic and ionic conducting constituents of the membrane electrode assembly; and (5) Improving reactant to and product mass transport away from the electroactive sites. Recent novel approaches include the nanoengineering of core shell catalysts and Pt particles of unusual geometries such as nanowires/whiskers. The success of the aforementioned approaches has been great; however further advances using such approaches have been hampered by a lack of underlining scientific understanding of the catalyst activity, particle growth mechanisms, and optimization strategies for designing composite electrodes The objectives of this report are: (1) Development of durable, high mass activity Platinum Group Metal (PGM) cathode catalysts-enabling lower cost fuel cells; (2) Elucidation of the fundamental relationships between PGM catalyst shape, particle size and activity to help design better catalysts; (3) Optimization of the cathode electrode layer to maximize the performance of PGM catalysts-improving fuel cell performance and lowering cost; (4) Understanding the performance degradation mechanisms of high mass activity cathode catalysts-provide insights to better catalyst design; and (5) Development and testing of fuel cells using ultra-low loading high activity PGM catalysts-validation of advanced concepts.

08 HYDROGEN↗