Search NASA⌕ Search

SEARCH · Search NASA

Results for “Capacity Factor”

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.

At least 1,153 records · Page 64
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Planned Relocation: A Pluralistic and Integrated Approach to Science and Governance

Planned relocation is an ambitious objective that occurs in complex governance settings rife with inequalities of power, discrimination, distrust, deep uncertainty, misalignment of incentives and authorities, and other challenges. Taking planned relocation from ambition to an equitable and effective portfolio of measures will require changes in science, governance and how they work together. Research will need to understand perverse incentives, conflicts, limits to risk perception, and other factors across individuals, communities, governance levels, and sectors. Knowledge to enable planned relocation will emerge not just from technical studies but from entwined processes of action, learning and capacity building. Science and governance must advance their collaboration to better support and learn from these tangled processes to identify adaptive pathways, build agency and implement strategies under deep uncertainty.

global environmental change, adapatation, decision↗
DOE OSTI2025

Reevaluation of Radiation-Protection Standards for Workers and the Public Based on Current Scientific Evidence

President Trump’s recent executive orders to “Usher in a Nuclear Renaissance,” coupled with the global pledge to triple nuclear energy capacity by 2050, underscore nuclear energy’s importance to national security and economic prosperity. This renewed interest has prompted efforts to spur nuclear-energy deployment, including assessing factors impeding it. One issue that has previously been identified as adding to the cost of nuclear energy is excessively conservative requirements, including those related to radiation protection. This technical review, therefore, examines current radiation-protection standards that were established decades ago when more limited data were available and nuclear-energy expansion was not a national priority. The review focuses on scientific evidence regarding the health effects of ionizing radiation at annual doses of 10,000 mrem or less. The review evaluates epidemiological studies, radiobiological research, and positions of relevant professional organizations to assess whether such doses result in discernable or observable increases in negative health outcomes. The review also surveys the literature related to economic and practical implications of current radiation-protection standards and practices. Based on this assessment, we propose maintaining an annual occupational whole-body dose limit of 5,000 mrem/yr and eliminating all “as low as reasonably achievable” requirements and limits below this threshold. This change could potentially reduce radiation-protection costs by millions of dollars annually for each reactor, as well as decrease the overall costs and correct misconceptions about the risks associated with all nuclear technologies. The evidence further supports future consideration of a 10,000 mrem/yr limit that would maintain appropriate safety margins while further reducing protection costs. Similarly, given the data and that the average annual radiation dose per person in the U.S. is 620 mrem, we believe the public dose limits of 100 mrem/yr are unnecessarily restrictive; increasing to 500 mrem/yr would maintain substantial safety margins—a factor of 10 below the occupational limit—while reducing regulatory burdens and associated bureaucracy. While we acknowledge ongoing scientific debate and encourage continued research on the health effects of ionizing radiation, our review indicates current frameworks are overly conservative. These overly stringent limits not only impose unnecessary economic burdens without corresponding health benefits but also divert safety focus and resources from more important considerations. Although this study was motivated by nuclear-power considerations, reforms to radiation-protection requirements have significant positive implications for other areas, such as nuclear medical applications, environmental remediation, nuclear-waste management and disposal, and industrial applications of nuclear technologies.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2024

Building Stock Models for Embodied Carbon Emissions—A Review of a Nascent Field

Building stock modeling emerges as a critical tool in the strategic reduction of embodied carbon emissions, which is pivotal in reshaping the evolving construction sector. This review provides an overall view of modern methodologies in building stock modeling, homing in on the nuances of embodied carbon analysis in construction. Examining 23 seminal papers, our study delineates two primary modeling paradigms—top-down and bottom-up—each further compartmentalized into five innovative methods. This study points out the challenges of data scarcity and computational demands, advocating for methodological advancements that promise to refine the precision of building stock models. A groundbreaking trend in recent research is the incorporation of machine learning algorithms, which have demonstrated remarkable capacity, improving stock classification accuracy by 25% and urban material quantification by 40%. Furthermore, the application of remote sensing has revolutionized data acquisition, enhancing data richness by a factor of five. This review offers a critical examination of current practices and charts a course toward an environmentally prudent future. It underscores the transformative impact of building stock modeling in driving ecological stewardship in the construction industry, positioning it as a cornerstone in the quest for sustainability and its significant contribution toward the grand vision of an eco-efficient built environment.

Hu, Ming (ORCID:0000000325831161)↗
NASA NTRS1985

The results of a limited study of approaches to the design, fabrication, and testing of a dynamic model of the NASA IOC space station. Executive summary

The options for the design, construction, and testing of a dynamic model of the space station were evaluated. Since the definition of the space station structure is still evolving, the Initial Operating Capacity (IOC) reference configuration was used as the general guideline. The results of the studies treat: general considerations of the need for and use of a dynamic model; factors which deal with the model design and construction; and a proposed system for supporting the dynamic model in the planned Large Spacecraft Laboratory.

Brooks, George W.↗
DOE OSTI2019

Energy Research at Idaho National Laboratory

Energy-related research at Idaho National Laboratory (INL) takes many forms. In this presentation, Liam Boire will step through a specific, on-going research project at INL which seeks to understand transmission grid resilience, and the components which can be improved to increase the resilience of our electrical infrastructure. While utilities and researchers similarly strive to improve power grid reliability, the frequency of large power outages are increasing. Thus, the importance for developing efficient methodologies that enable utilities and researchers alike to identify the most effective areas for improvement within the electric grid is more critical than ever. The method developed during this project recognized that a variety of factors were important to consider when identifying areas for improvement in the electric grid. Physics-based simulators are able to calculate voltage stability, load draws and generation capacities, and enumerate the combinations of component failures which result in system-wide failures (blackout scenarios). Probabilistic Risk Assessment (PRA) is able to assign probabilities to these failure scenarios based on typical component data (or more specific data if a specific system is being analyzed), and thus prioritize the list of failure scenarios based on likelihood and the components based on importance. Finally, adaptive capacity models can simulate the candidate grid and evaluate real and reactive power generation versus demand over time, calculating the total adaptive capacity available in various regions of the grid. The less adaptive capacity a region has, the less “buffer” that region has from failure. Not only are the individual results of these analyses valuable in understanding grid resilience, but the results of these analyses can be cross-correlated for deeper insight. When a grid is analyzed with this approach, failure scenarios can be enumerated and ranked by likelihood, components can be ranked by likelihood to drive system-wide failure, regions can be evaluated for adaptive capacity, and sensitive regions can be identified by recognizing the locations of important components within sensitive regions. Following this detailed discussion, a brief overview of some of the other energy research and areas of interest for the lab will be presented.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2020

Case Study of ISO/TS 6336-22 Micropitting Method: Preprint

ISO/TS 6336-22 (Calculation of load capacity of spur and helical gears — Part 22: Calculation of micropitting load capacity) is the ISO technical specification containing a proposal for a method to calculate the risk of micropitting in gear sets. It assesses micropitting risk through a safety factor which is calculated as the minimum specific film thickness in the contact zone divided by a permissible specific film thickness. A sliding parameter is used to adjust the film thickness in the contact zone to the region of highest sliding, which is where micropitting has been observed. The permissible specific film thickness is best determined through experience or testing, but there is an option to estimate it based on the lubricant’s failure load stage in FZG testing. This paper is a case study of how the method behaves when applied to several gear sets and applications that have experienced micropitting in the field.

gears↗
DOE OSTI2020

Case Study of ISO/TS 6336-22 Micropitting Calculation

ISO/TS 6336-22 (Calculation of load capacity of spur and helical gears - Part 22: Calculation of micropitting load capacity) is the ISO technical specification containing a proposal for a method to calculate the risk of micropitting in gear sets. It assesses micropitting risk through a safety factor which is calculated as the minimum specific film thickness in the contact zone divided by a permissible specific film thickness. A sliding parameter is used to adjust the film thickness in the contact zone to the region of highest sliding, which is where micropitting has been observed. The permissible specific film thickness is best determined through experience or testing, but there is an option to estimate it based on the lubricant’s failure load stage in FZG testing. This paper is a case study of how the method behaves when applied to several gear sets and applications that have experienced micropitting in the field.

ENGINEERING,WIND ENERGY↗
DOE OSTI2014

HybridPlan: A Capacity Planning Technique for Projecting Storage Requirements in Hybrid Storage Systems

Economic forces, driven by the desire to introduce flash into the high-end storage market without changing existing software-base, have resulted in the emergence of solid-state drives (SSDs), flash packaged in HDD form factors and capable of working with device drivers and I/O buses designed for HDDs. Unlike the use of DRAM for caching or buffering, however, certain idiosyncrasies of NAND Flash-based solid-state drives (SSDs) make their integration into hard disk drive (HDD)-based storage systems nontrivial. Flash memory suffers from limits on its reliability, is an order of magnitude more expensive than the magnetic hard disk drives (HDDs), and can sometimes be as slow as the HDD (due to excessive garbage collection (GC) induced by high intensity of random writes). Given the complementary properties of HDDs and SSDs in terms of cost, performance, and lifetime, the current consensus among several storage experts is to view SSDs not as a replacement for HDD, but rather as a complementary device within the high-performance storage hierarchy. Thus, we design and evaluate such a hybrid storage system with HybridPlan that is an improved capacity planning technique to administrators with the overall goal of operating within cost-budgets. HybridPlan is able to find the most cost-effective hybrid storage configuration with different types of SSDs and HDDs

Capacity Planning↗
DOE OSTI2013

Preparation and characterization of MnFe{sub 2}O{sub 4} in the solvothermal process: Their magnetism and electrochemical properties

Graphical abstract: - Highlights: • Effect of CTAB on the morphology and crystallization of MnFe{sub 2}O{sub 4}. • The lowest coercivity of MnFe{sub 2}O{sub 4} polyhedron is 11.9 Oe. • MnFe{sub 2}O{sub 4} as anode for LIB shows good reversible capacity and cycle performances. - Abstract: The uniform different morphologies MnFe{sub 2}O{sub 4}, including cube, truncated cube, polyhedron and octahedron, were successfully synthesized via a solvothermal route using cetyltrimethylammonium bromide. The results of control experiments revealed that the concentration of cetyltrimethylammonium bromide was an important factor, which affected the morphology and crystallization of MnFe{sub 2}O{sub 4} submicro-crystals. All the prepared samples exhibited soft-magnetic behavior at room temperature. Especially, the coercivity of MnFe{sub 2}O{sub 4} polyhedron with 200 nm diameter was 11.9 Oe, which was among the lowest values reported so far. Moreover, MnFe{sub 2}O{sub 4} submicro-crystals with special morphologies demonstrated higher reversible capacity (about 1000 mAh g{sup −1}) and different cycle performances. After 50 cycles, polyhedron structure remained 428 mAh/g. The MnFe{sub 2}O{sub 4} would have a potential application as anode material for lithium ion batteries.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Combined Heat and Power: A Clean Energy Solution, August 2012

This paper provides a foundation for national discussions on effective ways to reach the 40 gigawatts (GW) target, and includes an overview of the key issues currently impacting CHP deployment and the factors that need to be considered by stakeholders participating in the dialogue.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2022

Commercial Building Planning and Retrofitting Strategy for Grid Services

The increasing integration of distributed energy resources (DERs) plays an important role in improving energy consumption efficiency. In September 2020, the Federal Energy Regulatory Commission (FERC) approved Order 2222 which opens wholesale electricity markets to small capacity DERs. The benefit of this new FERC Order 2222 is that DERs, such as rooftop solar panels and batteries, will be able to participate in regional electricity markets and provide grid services. Meanwhile, the planning and operation strategies of DERs are facing new challenges to account for the impact of the wholesale market with numerous uncertainty factors. Therefore, in this paper, we propose a new planning and retrofitting model for long-term commercial buildings that considers both DER investment and market participation. Specifically, we explore the capability of implementing DERs for grid services. The effectiveness of the proposed model is validated using real-world data. Simulation results also validate that participating in grid services can significantly increase revenues through appropriate building energy management and shorten the payback period of DER investments.

building energy management↗
DOE OSTI2019

Analysis of the Pressure-Pulse Propagation in Rock: a New Approach to Simultaneously Determine Permeability, Porosity, and Adsorption Capacity

Permeability estimation from pressure-pulse decay method is complicated by two facts: (1) the decay curve often deviates from the single-exponential behavior in the early time period and (2) possible existence of gas adsorption. Both the two factors cause significant permeability error in most of pressure-pulse decay methods. In this paper, we first present a thorough analysis of pressure-pulse propagation process to reveal the mechanism behind the early time and later time behaviors of pressure decay curve. Inspired by the findings from these analyses, a new scaled pressure is proposed which can: (1) be easily used to distinguish the early time and later time data and (2) make the decay curves of all cases into a single 1:1 straight line for later time. A new data-proceeding method, which calculates the apparent porosity and permeability using the same set of measured data, is then developed. The new method could not only remove the effects of the adsorption on the permeability estimation, but also identify the apparent porosity as well as proper adsorption model and parameters. The proposed method is verified by comparing with true values and calculated values through numerical simulations that cover variations in typical rock properties (porosity, permeability, slippage, and adsorption) and the experiment configurations. It is found that the new method is accurate and reliable for all test cases, whereas the Brace’s and Cui’s approaches may cause permeability error in some cases. Lastly, the new method has been successfully applied to real data measured in pressure-pulse decay experiments involving different types of rocks and gases.

58 GEOSCIENCES↗
DOE OSTI2015

Developmental bisphenol A (BPA) exposure leads to sex-specific modification of hepatic gene expression and epigenome at birth that may exacerbate high-fat diet-induced hepatic steatosis

Developmental bisphenol A (BPA) exposure increases adulthood hepatic steatosis with reduced mitochondrial function. To investigate the potential epigenetic mechanisms behind developmental BPA-induced hepatic steatosis, pregnant Sprague–Dawley rats were dosed with vehicle (oil) or BPA (100 μg/kg/day) from gestational day 6 until postnatal day (PND) 21. After weaning, offspring were either challenged with a high-fat (HF; 45% fat) or remained on a control (C) diet until PND110. From PND60 to 90, both BPA and HF diet increased the fat/lean ratio in males only, and the combination of BPA and HF diet appeared to cause the highest ratio. On PND110, Oil-HF, BPA-C, and BPA-HF males had higher hepatic lipid accumulation than Oil-C, with microvesicular steatosis being marked in the BPA-HF group. Furthermore, on PND1, BPA increased and modified hepatic triglyceride (TG) and free fatty acid (FFA) compositions in males only. In PND1 males, BPA increased hepatic expression of FFA uptake gene Fat/Cd36, and decreased the expression of TG synthesis- and β-oxidation-related genes (Dgat, Agpat6, Cebpα, Cebpβ, Pck1, Acox1, Cpt1a, Cybb). BPA altered DNA methylation and histone marks (H3Ac, H4Ac, H3Me2K4, H3Me3K36), and decreased the binding of several transcription factors (Pol II, C/EBPβ, SREBP1) within the male Cpt1a gene, the key β-oxidation enzyme. In PND1 females, BPA only increased the expression of genes involved in FFA uptake and TG synthesis (Lpl, Fasn, and Dgat). These data suggest that developmental BPA exposure alters and reprograms hepatic β-oxidation capacity in males, potentially through the epigenetic regulation of genes, and further alters the response to a HF diet. - Highlights: • Developmental BPA exposure exacerbates HF-diet induced steatosis in adult males. • Gestational BPA exposure increases hepatic lipid accumulation in neonatal males. • BPA decreases Cpt1a and other hepatic β-oxidation genes in neonatal males. • BPA alters neonatal male Cpt1a DNA methylation, histones, and transcription factors.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

Evidence-based indicator approach to guide preliminary environmental impact assessments of hydropower development

Global expansion of hydropower resources has increased in recent years to meet growing energy demands and fill worldwide gaps in electricity supply. However, hydropower induces significant environmental impacts on river ecosystems - impacts that are addressed through environmental impact assessment (EIA) processes. The need for effective EIA processes is increasing as environmental regulations are either stressed in developing countries undertaking rapid expansion of hydropower capacity or time- and resource-intensive in developed countries. Part of the challenge in implementing EIAs lies in reaching a consensus among stakeholders regarding the most important environmental factors as the focus of impact studies. To help address this gap, we developed a weight-of-evidence approach (and toolkit) as a preliminary and coarse assessment of the most relevant impacts of hydropower on primary components of the river ecosystem, as identified using river function indicators. Through a science-based questionnaire and predictive model, users identify which environmental indicators may be impacted during hydropower development as well as those indicators that have the highest levels of uncertainty and require further investigation. Furthermore, an assessment tool visualizes inter-dependent indicator relationships, which help formulate hypotheses about causal relationships explored through environmental studies. We apply these tools to four existing hydropower projects and one hypothetical new hydropower project of varying sizes and environmental contexts. We observed consistencies between the output of our tools and the Federal Energy Regulatory Commission licensing process (inclusive of EIAs) but also important differences arising from holistic scientific evaluations (our toolkit) versus regulatory policies. The tools presented herein are aimed at increasing the efficiency of the EIA processes that engender environmental studies without loss of rigor or transparency of rationale necessary for understanding, considering, and mitigating the environmental consequences of hydropower.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Characterizing Drought Behavior in the Colorado River Basin Using Unsupervised Machine Learning

Drought is a pressing issue for the Colorado River Basin (CRB) due to the social and economic value of water resources in the region and the significant uncertainty of future drought under climate change. Here, we use climate simulations from various Earth System Models (ESMs) to force the Variable Infiltration Capacity hydrologic model and project multiple drought indicators for the sub-watersheds within the CRB. We apply an unsupervised machine learning (ML) based on Non-Negative Matrix Factorization using K-means clustering (NMFk) to synthesize the simulated historical, future, and change in drought indicators. The unsupervised ML approach can identify sub-watersheds where key changes to drought indicator behavior occur, including shifts in snowpack, snowmelt timing, precipitation, and evapotranspiration. While changes in future precipitation vary across ESMs, the results indicate that the Upper CRB will experience increasing evaporative demand and surface-water scarcity, with some locations experiencing a shift from a radiation-limited to a water-limited evaporation regime in the summer. Large shifts in peak runoff are observed in snowmelt-dominant sub-watersheds, with complete disappearance of the snowmelt signal for some sub-watersheds. The work demonstrates the utility of the NMFk algorithm to efficiently identify behavioral changes of drought indicators across space and time and to quickly analyze and interpret hydro climate model results.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Comparative metagenomics of hydrocarbon and methane seeps of the Gulf of Mexico

Oil and gas percolate profusely through the sediments of the Gulf of Mexico, leading to numerous seeps at the seafloor, where complex microbial, and sometimes animal communities flourish. Sediments from three areas (two cold seeps with contrasting hydrocarbon composition and a site outside any area of active seepage) of the Gulf of Mexico were investigated and compared. Consistent with the existence of a seep microbiome, a distinct microbial community was observed in seep areas compared to sediment from outside areas of active seepage. The microbial community from sediments without any influence from hydrocarbon seepage was characterized by Planctomycetes and the metabolic potential was consistent with detrital marine snow degradation. By contrast, in seep samples with methane as the principal hydrocarbon, methane oxidation by abundant members of ANME-1 was likely the predominant process. Seep samples characterized by fluids containing both methane and complex hydrocarbons, were characterized by abundant Chloroflexi (Anaerolinaceae) and deltaproteobacterial lineages and exhibited potential for complex hydrocarbon degradation. These different metabolic capacities suggested that microorganisms in cold seeps can potentially rely on other processes beyond methane oxidation and that the hydrocarbon composition of the seep fluids may be a critical factor structuring the seafloor microbial community composition and function.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

EuCo 2 P 2 : A Model Molecular-Field Helical Heisenberg Antiferromagnet

The metallic compound EuCo 2 P 2 with the body-centered tetragonal ThCr 2 Si 2 structure containing Eu spins-7/2 was previously shown from single-crystal neutron diffraction measurements to exhibit a helical antiferromagnetic (AFM) structure below T N =66.5 K with the helix axis along the c axis and with the ordered moments aligned within the ab plane. Here we report crystallography, electrical resistivity, heat capacity, magnetization, and magnetic susceptibility measurements on single crystals of this compound. We demonstrate that EuCo 2 P 2 is a model molecular-field helical Heisenberg antiferromagnet from comparisons of the anisotropic magnetic susceptibility χ, high-field magnetization, and magnetic heat capacity of EuCo 2 P 2 single crystals at temperature T≤TN with the predictions of our recent formulation of molecular-field theory. Values of the Heisenberg exchange interactions between the Eu spins are derived from the data. The low-T magnetic heat capacity ~T 3 arising from spin-wave excitations with no anisotropy gap is calculated and found to be comparable to the lattice heat capacity. The density of states at the Fermi energy of EuCo 2 P 2 and the related compound BaCo 2 P 2 are found from the heat capacity data to be large, 10 and 16 states/eV per formula unit for EuCo 2 P 2 and BaCo 2 P 2 , respectively. These values are enhanced by a factor of ~2.5 above those found from DFT electronic structure calculations for the two compounds. Additionally, the calculations also find ferromagnetic Eu–Eu exchange interactions within the ab plane and AFM interactions between Eu spins in nearest- and next-nearest planes, in agreement with the MFT analysis of χ ab (T≤TN).

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2011

Building Stronger State Partnerships With the US Dept. Of Energy (Energy Assurance)

From 2007 until 2011, the National Association of Regulatory Utility Commissioners (NARUC) engaged in a partnership with the National Energy Technology Lab (NETL) to improve State-Federal coordination on electricity policy and energy assurance issues. This project allowed State Public Utility Commissioners and their staffs to engage on the most cutting-edge level in the arenas of energy assurance and electricity policy. Four tasks were outlined in the Statement of Performance Objectives: Task 1 - Training for Commissions on Critical Infrastructure Topics; Task 2 - Analyze and Implement Recommendations on Energy Assurance Issues; Task 3 - Ongoing liaison activities & outreach to build stronger networks between federal agencies and state regulators; and Task 4 - Additional Activities. Although four tasks were prescribed, in practice these tasks were carried out under two major activity areas: the critical infrastructure and energy assurance partnership with the US Department of Energy's Infrastructure Security and Emergency Response office, and the National Council on Electricity Policy, a collaborative which since 1994 has brought together State and Federal policymakers to address the most pressing issues facing the grid from restructuring to smart grid implementation. On Critical Infrastructure protection, this cooperative agreement helped State officials yield several important advances. The lead role on NARUC's side was played by our Committee on Critical Infrastructure Protection. Key lessons learned in this arena include the following: (1) Tabletops and exercises work - They improve the capacity of policymakers and their industry counterparts to face the most challenging energy emergencies, and thereby equip these actors with the capacity to face everything up to that point as well. (2) Information sharing is critical - Connecting people who need information with people who have information is a key success factor. However, exposure of critical infrastructure information to bad actors also creates new vulnerabilities. (3) Tensions exist between the transparency-driven basis of regulatory activity and the information-protection requirements of asset protection. (4) Coordination between states is a key success factor - Because comparatively little federal authority exists over electricity and other energy infrastructure, the interstate nature of these energy grids defy centralized command and control governance. Patchwork responses are a risk when addressed at a state-by-state level. Coordination is the key to ensuring consistent response to shared threats. In Electricity Policy, the National Council on Electricity Policy continued to make important strides forward. Coordinated electricity policy among States remains the best surrogate for an absent national electricity policy. In every area from energy efficiency to clean coal, State policies are driving the country's electricity policy, and regional responses to climate change, infrastructure planning, market operation, and new technology deployment depend on a forum for bringing the States together.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗