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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 667 records · Page 37
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Verification of J-integral capability in Sierra Mechanics

A finite-deformation, massively parallel, domain J -integral has been developed in Sierra Me- chanics with specific emphasis on pressurized loadings. We review the development of the domain integral and the inclusion of terms to correct for boundary tractions. We note the syntax employed in Sierra and illustrate the choice of weight function. Details are provided regarding domain selection, erack direction, and the construction of the test function. Be- cause quality meshes are required to obtain accurate measures of the driving force, methods were developed in Cubit for creating element boundaries orthogonal to the crack front. We briefly review the new capabilities and provide guidance for mesh construction. A compre- hensive set of examples illustrate the current implementation in Sierra. Examples include straight crack fronts, curved crack fronts, and non-planar crack faces. We investigate elastic and elastic-plastic cases. The inclusion of boundary tractions is verified through a pressur- ized ellipsoidal flaw. When possible, the calculated driving forees are compared to analytical solutions. Although the J -integral is available in many commercial codes, the finite defor- mation implementation in Sierra will enable analysts to examine detailed component level models and include fracture mechanics as a tool in the Sandia design process.

Ohashi, Yuki↗
DOE OSTI2013

Life Cycle Greenhouse Gas Emissions from Electricity Generation (Fact Sheet)

Analysts at NREL have developed and applied a systematic approach to review the LCA literature, identify primary sources of variability and, where possible, reduce variability in GHG emissions estimates through a procedure called 'harmonization.' Harmonization of the literature provides increased precision and helps clarify the impacts of specific electricity generation choices, producing more robust results.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2013

Successful Track Record with Diverse Policies (Fact Sheet)

The Clean Energy Solutions Center helps governments, advisors, and analysts create policies and programs that advance the deployment of clean energy technologies. Through its no-cost offerings, the Solutions Center enables countries to learn from and share policy best practices, data, and analysis tools, creating an international dialogue on clean energy policies that raises global awareness of emerging policy issues and innovations. As part of these efforts, the Solutions Center provides an indispensable service by connecting those seeking policy information and advice with a policy expert who can help them achieve their goals. The Solutions Center's Ask an Expert service matches policymakers with one of the more than 30 global experts selected as authoritative leaders on specific clean energy policy topics.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2013

Training and Peer-to-Peer Learning (Fact Sheet)

The Clean Energy Solutions Center helps governments, advisors, and analysts create policies and programs that advance the deployment of clean energy technologies. The Solutions Center is an initiative of the Clean Energy Ministerial (CEM), a global forum to share best practices and promote policies and programs that encourage and facilitate the transition to a global clean energy economy, and UN-Energy, the United Nations' interagency mechanism to scale-up global clean energy use.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2013

NREL Leads Energy Systems Integration, Continuum Magazine: Issue 4 (Book)

Continuum Magazine showcases NREL's latest and most impactful clean energy innovations. This issue, 'NREL Leads Energy Systems Integration' explores the discipline of energy systems integration, in particular the role of the laboratory's new, one-of-a-kind Energy System Integration Facility. NREL scientists, engineers, and analysts deeply understand the fundamental science and technologies underpinning major energy producing and consuming systems, as well as the transmission infrastructure and communications and data networks required to integrate energy systems at all scales.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

Initial Assessment of an Airborne Ku-band Polarimetric SAR

Polarimetric synthetic aperture radar (SAR) has been used for a variety of dual-use research applications since the 1940's. By measuring the direction of the electric field vector from radar echoes, polarimetry may enhance an analyst's understanding of scattering effects for both earth monitoring and tactical surveillance missions. Polarimetry may provide insight into surface types, materials, or orientations for natural and man-made targets. Polarimetric measurements may also be used to enhance the contrast between scattering surfaces such as man-made objects and their surroundings. This report represents an initial assessment of the utility of, and applications for, polarimetric SAR at Ku-band for airborne or unmanned aerial systems.

Raynal, Ann Marie↗
DOE OSTI2013

Development of a statistically based access delay timeline methodology.

The charter for adversarial delay is to hinder access to critical resources through the use of physical systems increasing an adversary s task time. The traditional method for characterizing access delay has been a simple model focused on accumulating times required to complete each task with little regard to uncertainty, complexity, or decreased efficiency associated with multiple sequential tasks or stress. The delay associated with any given barrier or path is further discounted to worst-case, and often unrealistic, times based on a high-level adversary, resulting in a highly conservative calculation of total delay. This leads to delay systems that require significant funding and personnel resources in order to defend against the assumed threat, which for many sites and applications becomes cost prohibitive. A new methodology has been developed that considers the uncertainties inherent in the problem to develop a realistic timeline distribution for a given adversary path. This new methodology incorporates advanced Bayesian statistical theory and methodologies, taking into account small sample size, expert judgment, human factors and threat uncertainty. The result is an algorithm that can calculate a probability distribution function of delay times directly related to system risk. Through further analysis, the access delay analyst or end user can use the results in making informed decisions while weighing benefits against risks, ultimately resulting in greater system effectiveness with lower cost.

Rivera, W. Gary↗
DOE OSTI2013

Data co-processing for extreme scale analysis level II ASC milestone (4745).

Exascale supercomputing will embody many revolutionary changes in the hardware and software of high-performance computing. A particularly pressing issue is gaining insight into the science behind the exascale computations. Power and I/O speed con- straints will fundamentally change current visualization and analysis work ows. A traditional post-processing work ow involves storing simulation results to disk and later retrieving them for visualization and data analysis. However, at exascale, scien- tists and analysts will need a range of options for moving data to persistent storage, as the current o ine or post-processing pipelines will not be able to capture the data necessary for data analysis of these extreme scale simulations. This Milestone explores two alternate work ows, characterized as in situ and in transit, and compares them. We nd each to have its own merits and faults, and we provide information to help pick the best option for a particular use.

Rogers, David↗
DOE OSTI2012

Treated Wood Waste Identification and Characterization

At LLNL different program areas may encounter treated wood waste and need to determine the appropriate disposal method. Disposal option decisions are to be made by the generator, environmental analyst (EA) and, if needed, support from RHWM. If the generator decides to use the Treated Wood exemption, the regulatory guidance and characterization support is provided in this paper. For additional support RHWM can be contacted through the assigned area Field Technician. Otherwise if the generator and the EA decide to opt for the exemption path then the regulations and controls referenced in this paper have to be initiated and followed. Pressure treated wood presents an issue for identification and waste processing. It has the potential to be in construction waste in facility structures and in outside construction, such as porches, steps, landscaping borders. The difficulty is in easy identification and characterization without costly analytical support and obtaining information in the post D&D phase of an operation. The following guidance presents an easy solution to this characterization issue. This paper is limited to Chromated Copper Arsenate (CCA) and other related metal treated wood. The local availability and the lack of an alternative to direct chemical analysis for identification and characterization prevented the inclusion of organic wood preservatives in this study.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Measure Guideline: Buried and/or Encapsulated Ducts

Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. This Building America Measure Guideline synthesizes previously published research on BEDs and provides practical information to builders, contractors, homeowners, policy analysts, building professions, and building scientists. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license. Persons implementing duct system improvements should not go beyond their expertise or qualifications. This guideline provides valuable information for a building industry that has struggled to address ductwork thermal losses in new and existing homes. As building codes strengthen requirements for duct air sealing and insulation, flexibility is needed to address energy efficiency goals. While ductwork in conditioned spaces has been promoted as the panacea for addressing ductwork thermal losses, BEDs installations approach - and sometimes exceed - the performance of ductwork in conditioned spaces.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

A review of macroscopic ductile failure criteria.

The objective of this work was to describe several of the ductile failure criteria com- monly used to solve practical problems. The following failure models were considered: equivalent plastic strain, equivalent plastic strain in tension, maximum shear, Mohr- Coulomb, Wellman's tearing parameter, Johnson-Cook and BCJ MEM. The document presents the main characteristics of each failure model as well as sample failure predic- tions for simple proportional loading stress histories in three dimensions and in plane stress. Plasticity calculations prior to failure were conducted with a simple, linear hardening, J2 plasticity model. The resulting failure envelopes were plotted in prin- cipal stress space and plastic strain space, where the dependence on stress triaxiality and Lode angle are clearly visible. This information may help analysts select a ductile fracture model for a practical problem and help interpret analysis results.

Corona, Edmundo↗
DOE OSTI2013

Chloride and Fluoride Analysis Methods in Support of the Americium Recovery Program

ide determinations in AmO2. A relevant reference document is ASTM C698-10 Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Mixed Oxides ((U, Pu)O2). The main AmO2 analysis goals would be to meet the customers’ specifications with the minimum radiation dose to the analyst. Specifications any more stringent than the MOX program (Cl, F Sum ≤ 500 ppm (No one > 300 ppm)) will limit the methods under consideration. Presented here are the current analysis method along with a specific procedure modification for the analysis of Cl and F in support of the Americium Recovery Program.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

Application of Subspace Detectors to 2012 Sumatera Earthquake Sequence

In this report the aftershock sequence of the 2012 Sumatra earthquake is used to study the performance of subspace detectors (Harris, 2006) to detect and classify the events. The ground truth used for this study is 1222 aftershock solutions from the LLNL database drawn mostly from the Reviewed Event Bulletin (REB). Subspace detectors are built using several spawning strategies with waveforms recorded by the Makanchi Array (MKAR). Because we desire the subspace detectors to have a very low false alarm rate, the subspace templates are required to be about 50 seconds long (most of the P-bundle). For the same reason, the power detections used to create the subspace templates are restricted to have high SNR. Because of these restrictions, none of the subspace detectors are able to reproduce the entire ground truth catalog. They do have a very low false alarm rate, however, and so can reliably be used as single-array detection classifiers. Because of their reliability, in a suitably designed system, these detectors could be used to segregate detections from regions of high seismicity such as aftershock sequences, and allow processing of those detections in isolation from routine seismicity. It may also be possible to use these detectors to process groups of detections simultaneously. This leads to the concept of “analyst workload reduction factor”; a measure of the reduction in effort achieved by processing N detections in M groups instead of individually. If M is much smaller than N, a significant reduction factor is achieved.

58 GEOSCIENCES↗
DOE OSTI2013

NREL Develops OpenEI.org, a Public Website Where Energy Data can be Generated, Shared, and Compared (Fact Sheet)

The National Renewable Energy Laboratory (NREL) has developed OpenEI.org, a public, open, data-sharing platform where consumers, analysts, industry experts, and energy decision makers can go to boost their energy IQs, search for energy data, share data, and get access to energy applications. The free site blends elements of social media, linked open-data practices, and MediaWiki-based technology to build a collaborative environment for creating and sharing energy data with the world. The result is a powerful platform that is helping government and industry leaders around the world define policy options, make informed investment decisions, and create new businesses.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

NREL Case Study Leads to International Partnership: Innovation Impact - Analysis (Fact Sheet)

In 2012, NREL analysts produced a case study, "Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience," which drew upon dozens of interviews with international experts involved in crafting effective policies and markets. The report proposed a cross-cutting initiative to transform the world's power systems by implementing two complementary strategies: the large‐scale deployment of renewable energy, and a combination of comprehensive energy efficiency and smarter grids. This recommendation led to the launch of the 21st Century Power Partnership in April 2012, and its membership has since grown to include Denmark, Finland, Germany, India, Mexico, Spain, and the United States. NREL, together with its affiliated Joint Institute for Strategic Energy Analysis, are the operating agents.

21ST CENTURY POWER PARTNERSHIP↗
DOE OSTI2014

Achieving Robustness to Uncertainty for Financial Decision-making

This report investigates the concept of robustness analysis to support financial decision-making. Financial models, that forecast future stock returns or market conditions, depend on assumptions that might be unwarranted and variables that might exhibit large fluctuations from their last-known values. The analysis of robustness explores these sources of uncertainty, and recommends model settings such that the forecasts used for decision-making are as insensitive as possible to the uncertainty. A proof-of-concept is presented with the Capital Asset Pricing Model. The robustness of model predictions is assessed using info-gap decision theory. Info-gaps are models of uncertainty that express the “distance,” or gap of information, between what is known and what needs to be known in order to support the decision. The analysis yields a description of worst-case stock returns as a function of increasing gaps in our knowledge. The analyst can then decide on the best course of action by trading-off worst-case performance with “risk”, which is how much uncertainty they think needs to be accommodated in the future. The report also discusses the Graphical User Interface, developed using the MATLAB® programming environment, such that the user can control the analysis through an easy-to-navigate interface. Three directions of future work are identified to enhance the present software. First, the code should be re-written using the Python scientific programming software. This change will achieve greater cross-platform compatibility, better portability, allow for a more professional appearance, and render it independent from a commercial license, which MATLAB® requires. Second, a capability should be developed to allow users to quickly implement and analyze their own models. This will facilitate application of the software to the evaluation of proprietary financial models. The third enhancement proposed is to add the ability to evaluate multiple models simultaneously. When two models reflect past data with similar accuracy, the more robust of the two is preferable for decision-making because its predictions are, by definition, less sensitive to the uncertainty.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2014

AGR-2 Data Qualification Report for ATR Cycle 154B

This report provides the data qualification status of Advanced Gas Reactor-2 (AGR-2) fuel irradiation experimental data from Advanced Test Reactor (ATR) Cycle 154B as recorded in the Nuclear Data Management and Analysis System (NDMAS). This is the last cycle of AGR-2 irradiation, as the test train was pulled from the ATR core during the outage portion of ATR Cycle 155A. The AGR-2 data streams addressed in this report include thermocouple (TC) temperatures, sweep gas data (flow rates including new Fission Product Monitoring (FPM) downstream flows from Fission Product Monitoring System (FPMS) detectors, pressure, and moisture content), and FPMS data (release rates and release-to-birth rate ratios [R/Bs]) for each of the six capsules in the AGR-2 experiment. The final data qualification status for these data streams is determined by a Data Review Committee (DRC) comprised of AGR technical leads, Sitewide Quality Assurance (QA), and NDMAS analysts. The Data Review Committee reviewed the data acquisition process, considered whether the data met the requirements for data collection as specified in QA-approved Very High Temperature Reactor (VHTR) data collection plans, examined the results of NDMAS data testing and statistical analyses, and confirmed the qualification status of the data as given in this report.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2014

Nuclear Security: Evaluating a System (Path Analysis)

This presentation provides a system approach that evaluates each element of the PPS and how it contributes to overall system effectiveness; provides an elemental contribution that helps define performance requirements; provides a qualitative and quantitative aspect to PPS performance; and by way of a tool, allows analysts to combine and evaluate qualitative, quantitative data.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗