Assessing the relevant time frame for temperature acclimation of leaf dark respiration: A test with 10 boreal and temperate species
Not provided.
Biodiversity & Conservation↗
SEARCH · Engineering Papers
Results for “Assessment”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Assessment of the American Recovery and Reinvestment Act Upon the Department of Energy Weatherization Assistance Program: Assessment of the ARRA
The Department of Energy (DOE) administers the national low-income Weatherization Assistance Program (WAP). Under this program, DOE provides grants to states (grantees), which then provide grants to local weatherization agencies (subgrantees), to weatherize income-eligible homes for free. The American Recovery and Reinvestment Act (ARRA) of 2009 allocated $5 billion in funding to WAP, a very significant increase from an annual appropriation that ranged in the $200–250 million range for many years. Furthermore, as part of a major evaluation of WAP, states and local weatherization agencies were surveyed, in part, to assess their experiences during the ARRA period. The substantial funding increase created a number of issues for the national weatherization network: the political visibility of their programs increased significantly, organizational responsibilities were shifted, new laws and regulations were passed that impacted their programs, media attention of their programs increased, federal oversight of their programs increased; and programmatic costs increased because of the increased oversight and because ARRA required WAP to operate under the provisions of the Davis-Bacon Act of 1931. There was also some concern within the national weatherization network that the influx of ARRA funds would permanently damage nonfederal funding leveraging relationships. However, two-thirds of grantees and over 40% of subgrantees stated that they believe that the long-term impacts of ARRA on leveraging relationships will be positive.
54 ENVIRONMENTAL SCIENCES↗
Xyloglucan in the primary cell wall: assessment by FESEM, selective enzyme digestions and nanogold affinity tags
Explore the source record for details and available documents.
biofuels (including algae and biomass), bio-inspir↗
Numerical Analysis of Detonability Assessment in a Natural Gas-Air Fueled Rotating Detonation Engine
Rotating Detonation Engines (RDE) offer an alternative combustion strategy to replace conventional constant pressure combustion with a process that could produce a pressure gain without the use of a mechanical compressor. Recent numerical and experimental publications that consider air as the oxidizer have primarily focused on the ability of these annular combustors to sustain a stable continuous detonation wave when fueled by hydrogen. However, for this to be a viable consideration for the land-based power generation it is necessary to explore the ability to detonate natural gas and air within the confines of the annular geometry of an RDE. Previous studies on confined detonations have expressed the importance of permitting detonation cells to fully form within the combustor in order to achieve stability. This poses a challenge for natural gas–air fueled processes as their detonation cell size can be quite large even at moderate pressures. Despite the practical importance, only a few studies are available on natural gas detonations for air-breathing RDE applications. Moreover, the extreme thermodynamic condition (high temperature inside the combustor) allows limited accessibility inside the combustor for detailed experimental instrumentations, providing mostly single-point data. Recent experimental studies at the National Energy Technology Laboratory (NETL) have reported detonation failure at higher methane concentration in an air-breathing RDE fueled by natural gas-hydrogen fuel blends. This encourages to perform a detailed numerical investigation on the wave characteristics of detonation in a natural gas-air fueled RDE to understand the various aspects of instability associated with the natural gas-air detonation.This study is a numerical consideration of a methane-air fueled RDE with varying operating conditions to ascertain the ability to achieve a stable, continuous detonation wave. The simulations have been performed in a 2D unwrapped RDE geometry using the open-source CFD library “OpenFOAM” employing an unsteady pressure-based compressible reactive flow solver with a <em>k</em>–<em>ε</em> turbulence model in a structured rectangular grid system. Both reduced and detailed chemical kinetic models have been used to assess the effect of the chemistry on the detonation wave characteristics and the underlying flow features. A systematic grid sensitivity study has been conducted with various grid sizes to quantify the weakly stable overdriven detonation on a coarse mesh and oscillating features at fine mesh resolutions.The main focus of the current study is to investigate the effects of operating injection pressure on detonation wave characteristics of an air-breathing Rotating Detonation Engine (RDE) fueled with natural gas-hydrogen fuel blends. Wave speeds, peak pressures and temperatures, and dominant frequencies have been computed from the time histories. The flow structures were then visualized using 2D contours of temperature and species concentration.
Saha, Pankaj↗
Assessing the Effectiveness and Interactions of Instructional Coaches: Initial Psychometric Evidence for the Instructional Coaching Assessments–Teacher Forms
The conceptual foundation and initial psychometric evidence are provided for the Instructional Coaching Rating Scales and Interaction Style Scales–Teacher Forms. These forms are part of a multicomponent online assessment system designed to evaluate the effectiveness of coaching skills and interactions that support the needs of teachers and students. Specifically, the article presents the theory, evidence, and measurement framework for the system. Findings indicate that the Rating Scales and Interaction Style Scales–Teacher Forms have very good internal structures based on multiple fit statistics for confirmatory factor analyses, high internal consistency, good item-to-scale total correlations, and freedom from item bias. Collectively, this promising statistical evidence is supportive of valid score inferences. Study limitations and directions for research are discussed.
Reddy, Linda A.↗
Assessing Gaseous Hydrogen Assisted Fatigue Crack Growth Susceptibility of Pipeline Steel Weld Fusion Zones and Heat Affected Zones
The objective of this work was twofold: (1) measure reliable fatigue crack growth relationships for X65 steel and its girth weld in high-pressure hydrogen gas to enable structural integrity assessments of hydrogen pipelines, and (2) evaluate the hydrogen accelerated fatigue crack growth susceptibility of the weld fusion zone and heat-affected zone relative to the base metal. Fatigue crack growth relationships (da/dN versus ΔK) were measured for girth welded X65 pipeline steel in high pressure hydrogen gas (21 MPa) and in air. Hydrogen assisted fatigue crack growth was observed for the base metal (BM), fusion zone (FZ), and heat-affected zone (HAZ), and was manifested through crack growth rates reaching nearly an order of magnitude acceleration over rates in air. Addditionally, at higher ΔK values, crack growth rates of BM, FZ, and HAZ were coincident; however, at lower ΔK, the fatigue crack growth relationships exhibited some divergence with the fusion zone having the highest crack growth rates. These relative fatigue crack growth rates in the BM, FZ, and HAZ were provisional, however, since both crack closure and residual stress contributed to the crack-tip driving force in specimens extracted from the HAZ. Despite the relatively high applied R-ratio (R = 0.5), crack closure was detected in the heat affected zone tests, in contrast to the absence of crack closure in the base metal tests. Crack closure corrections were performed using the adjusted compliance ratio method and the effect of residual stress on K max was determined by the crack-compliance method. Crack-tip driving forces that account for closure and residual stress effects were quantified as a weighted function of ΔK and K max (i.e., K norm ), and the resulting da/dN versus K norm relationships showed that the HAZ exhibited higher hydrogen accelerated fatigue crack growth rates than the BM at lower K norm values.
36 MATERIALS SCIENCE↗
Technology Assessment for Proof-of-Concept UF6 Cylinder Unique Identification Task 3.1.2 Report – Survey and Assessment of Technologies
The National Nuclear Security Administration (NNSA) Office of Nonproliferation and International Security’s (NA-24) Next Generation Safeguards Initiative (NGSI) and the nuclear industry have begun to develop approaches to identify and monitor uranium hexafluoride (UF6) cylinders. The NA-24 interest in a global monitoring system for UF6 cylinders relates to its interest in supporting the International Atomic Energy Agency (IAEA) in deterring and detecting diversion of UF6 (e.g., loss of cylinder in transit) and undeclared excess production at conversion and enrichment facilities. The industry interest in a global monitoring system for UF6 cylinders relates to the improvements in operational efficiencies that such a system would provide. This task is part of an effort to survey and assess technologies for a UF6 cylinder to identify candidate technologies for a proof-of-concept demonstration and evaluation for the Cylinder Identification System (CIS).
Cylinder↗
2015 Assessment of Mercury in the Savannah River Site Environment and Responses to the Agency for Toxic Substances and Disease Registry 2012 Report on Assessment of Biota Exposure to Mercury Originating from the Savannah River Site
The purpose of this report is to 1) update previous Savannah River National Laboratory (SRNL) assessment reports (Kvartek et al. 1994 and Halverson et al. 2008) on the fate of mercury in the Savannah River Site (SRS) environment and 2) address comments and recommendations from the review of SRS by the Agency for Toxic Substances and Disease Registry (ATSDR) concerning the evaluation of exposures to contaminants in biota originating from the SRS. The ATSDR reviewed and evaluated data from SRS, South Carolina Department of Health & Environmental Control (SCDHEC) and the Georgia Department of Natural Resources (GDNR) concerning the non-radioactive contaminant mercury. This report will provide a response and update to conclusions and recommendations made by the ATSDR.
54 ENVIRONMENTAL SCIENCES↗
Assessment of Hanford Site Reduced Boundary Impacts: Limited Potential-to-Emit and Onsite Receptor Assessments
The U.S. Department of Energy’s Hanford Site Comprehensive Land Use Plan initiated this work to prospectively determine the potential impact of a proposed reduced Hanford Site controlled access boundary to the regulatory requirements of several radiological air emission units at the Hanford Site 200 Areas. The reduced boundary would allow access to portions of the Hanford Site that are currently closed to the public. In addition, doses to several representative members of the public are presented. The assessments to determine the impact to the potential-to-emit (PTE) dose indicated in the Hanford Site FF-01 Air Operating Permit show that only one of the evaluated stacks, located in the Hanford Site 200 West Area, has the potential to increase its PTE dose. This increased PTE dose result would not change its classification from a minor emission unit to a major emission unit. Dose estimates for representative members of the public are based on average external exposure and inhalation dose estimates. Doses are presented for a Hanford Site tour participant, an intermittent hiker in the Wye Barricade region, and a hiker in a generalized portion of newly opened areas south and west of the Columbia River.
40CFR61subpartH↗
Region-Specific Merchant Hydrogen Market Assessment and Techno-Economic Assessment of Electrolytic Hydrogen Generation: Cooperative Research and Development Final Report, CRADA Number CRD-18-00751
Utilities need to recover value from baseload and some renewable assets even when the electricity is curtailed. The declining cost of renewables (particularly solar), the persistently low-cost of natural gas, and the declining electricity demand, have all worked to lower the price of electricity. Furthermore, the baseload assets have a high turndown cost, which is not reflected in the low market electricity prices. One option for utilizing the curtailed electricity is hydrogen generation. One important aspect of this project will be to provide a “go/no-go” recommendation on the economic feasibility of pursuing hydrogen generation vs. other markets that could offtake curtailed electricity or nuclear steam. This project will specifically assess the opportunities for hydrogen production and use in the service territories of Southern Company Services (SCS), Exelon SBC, and Xcel Energy. Each utility partner represents a different mix of generation fleets: Exelon has significant nuclear assets, Xcel is primarily renewables (wind) with some nuclear, and SCS represents both a renewables fleet and a heavily baseload fleet, which includes significant nuclear. The Contractors will conduct the study of hydrogen market opportunities by first considering the approximate electricity demand and price profiles for the year, and power generation capacity that can be used to produce hydrogen. Therefore, a profile for hydrogen generation will also be developed to better understand the quantity and timing of hydrogen production. Once the hydrogen production schedule is estimated, hydrogen storage requirements can be determined. This effort will provide sufficient information to make a go/no-go decision on moving ahead with a detailed regional case study for hydrogen production in any of the three utility areas.
08 HYDROGEN↗
Modeling of High Solids Biomass Liquefaction, Techno-economic Assessment and Life Cycle Assessment for Industrial Scale UP
Biomass liquefaction improves corn-stover slurry transport within a biorefinery, and reduces challenges associated with solids handling. Slurries, formed with yield stresses (i.e., viscosities) that are low enough to facilitate pumping from one unit operation to the next, and that enable mixing at reasonable power inputs in large fermentation vessels, enable scaling of cellulose fermentations. Three liquefaction methods: enzyme, enzyme mimetic, and a hybrid approach were analyzed by a combination of techno-economic and life-cycle analyses, resulting in an assessment of cost-effectiveness and environmental impact. Of the three scenarios, enzyme-based processes emerged as the most efficient, both in cost and emissions reduction (gCO2-equivalent/kg slurry).
Ramirez, Jorge↗
Enhancing Site Screening for Underground Hydrogen Storage: Qualitative Site Quality Assessment - SHASTA: Subsurface Hydrogen Assessment, Storage, and Technology Acceleration Project
The global shift towards renewable energy sources to mitigate fossil fuel dependency and meet carbon emission targets by 2050 has underscored the importance of innovative solutions to address energy supply-demand imbalances. Underground Hydrogen Storage (UHS) has emerged as a promising strategy to store excess renewable energy in subsurface formations for future retrieval and utilization. This report focuses on enhancing the site screening process for UHS facilities. By drawing on insights from prior research to identify key criteria influencing site suitability, our objective is to present a comprehensive set of sixteen specific criteria essential for refining the selection of UHS sites. These criteria cover various aspects such as reservoir performance, legal access, regulatory compliance, economic viability, public acceptance, and safety and security considerations. Our proposed methodology allows users to evaluate potential sites using binary responses, transitioning from isolated factors to broader considerations that facilitate a qualitative assessment of site suitability. This method enables comparative analysis and informed decision-making, supporting stakeholders in the site selection process. Our approach is designed as a guiding framework rather than a rigid template for site screening, emphasizing the importance of customizing approaches to individual circumstances. As UHS site development project evolves, adopting a comprehensive selection methodology that integrates holistic evaluations will be essential for ensuring efficient and effective site screening processes tailored to specific project needs.
08 HYDROGEN↗
Enhancing Site Screening for Underground Hydrogen Storage: Qualitative Site Quality Assessment - SHASTA: Subsurface Hydrogen Assessment, Storage, and Technology Acceleration Project
The global shift towards renewable energy sources to mitigate fossil fuel dependency and meet carbon emission targets by 2050 has underscored the importance of innovative solutions to address energy supply-demand imbalances. Underground Hydrogen Storage (UHS) has emerged as a promising strategy to store excess renewable energy in subsurface formations for future retrieval and utilization. This report focuses on enhancing the site screening process for UHS facilities. By drawing on insights from prior research to identify key criteria influencing site suitability, our objective is to present a comprehensive set of sixteen specific criteria essential for refining the selection of UHS sites. These criteria cover various aspects such as reservoir performance, legal access, regulatory compliance, economic viability, public acceptance, and safety and security considerations. Our proposed methodology allows users to evaluate potential sites using binary responses, transitioning from isolated factors to broader considerations that facilitate a qualitative assessment of site suitability. This method enables comparative analysis and informed decision-making, supporting stakeholders in the site selection process. Our approach is designed as a guiding framework rather than a rigid template for site screening, emphasizing the importance of customizing approaches to individual circumstances. As UHS site development project evolves, adopting a comprehensive selection methodology that integrates holistic evaluations will be essential for ensuring efficient and effective site screening processes tailored to specific project needs.
08 HYDROGEN↗
Developing a geologic hydrogen resources assessment approach using AI-assisted literature review and geo-data driven assessment tool
Poster presentation for AGU 2024, presenting research approach to identify the natural hydrogen occurrence and to assess resource potential.
Seol, Yongkoo [NETL]↗
Assessing Cloud and Precipitation Properties on Temporal and Spatial Scales Using LASSO Simulations over ENA
Low clouds and precipitation representation remain a major source of uncertainty in Earth System Models (ESMs), particularly due to challenges in representing their sub-grid variability and scale-dependent sampling. This study evaluates the performance of preliminary simulations from the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) project over the Eastern North Atlantic (ENA), with a focus on liquid water path (LWP), ice water path (IWP), cloud fraction (CF), and surface precipitation simulated across closed-cell, open-cell, and transitional cloud regimes. Using LES (100 m horizontal grid spacing) driven by ERA5 and MERRA-2 reanalyses, we assess the representativeness of ground-based point observations by analyzing their correspondence to model-resolved spatial and temporal means. Results suggest that observational sampling of at least 6 hours is required to achieve consistency with domain-scale averages, in particular for observations that exhibit pronounced sub-grid heterogeneity, such as precipitation. ERA5-forced simulations exhibit improved spatial coherence and agreement with domain-averaged quantities when compared to MERRA-2 runs, with performance discrepancies largest for convective cloud conditions due to differences in forcing fidelity and temporal resolution. These findings highlight the importance of regime-aware model evaluation strategies and potentially demonstrate how LES can inform observation-model comparison practices and the development of cloud and precipitation parameterizations in ESMs.
Liang, Jiakun [University of Hawai'i at Manoa] (OR↗
CERF – A Geospatial Model for Assessing Future Energy Production Technology Expansion Feasibility
Electricity system expansion planning faces significant challenges not only because of commonly modeled uncertainties such as future demand growth, fuel prices, and technology cost and performance, but also because of challenges such as climate change and carbon policies that can affect supply and demand. Changes in energy technology, natural resource availability, and population migration and growth will affect the feasibility of power plant siting, potentially hindering the achievement of policy goals. New modeling approaches are needed that couple future projections of energy system expansion with “on the ground” feasibility modeling—where both are informed by a consistent set of assumptions about future climate trends, resource availability, climate policy, socioeconomics, and environmental regulations. This research describes the development and evaluation of the Capacity Expansion Regional Feasibility (CERF) model, a geospatial tool for scenario analysis of electricity system expansions.
grid expansion, water-energy nexus, power plant si↗
Independent Orbiter Assessment (IOA): Assessment of the electrical power generation/fuel cell powerplant subsystem FMEA/CIL
Results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Electrical Power Generation/Fuel Cell Powerplant (EPG/FCP) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. A resolution of each discrepancy from the comparison was provided through additional analysis as required. This report documents the results of that comparison for the Orbiter EPG/FCP hardware.
Brown, K. L.↗