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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Characterization factors and other air quality impact metrics: Case study for PM 2.5 -emitting area sources from biofuel feedstock supply

In this paper, we develop a framework and metrics for estimating the impact of emission sources on regulatory compliance and human health for applications in air quality planning and life cycle impact assessment (LCIA). Our framework is based on a pollutant's characterization factor (CF) and three new metrics: Available Regulatory Capacity for Incremental Emissions (ARCIE), Source CF Ratio, and Activity Health Impact (AHI) Ratio. ARCIE can be used to assess whether a receptor location has capacity to accommodate additional source emissions while complying with regulatory limits. We present CF as a midpoint indicator of health impacts per unit mass of emitted pollutant. Source CF Ratio enables comparison of potential new-source locations based on human health impacts. The AHI Ratio estimates the health impacts of a pollutant in relation to the utilization of the source for each unit of product or service. These metrics can be applied to any pollutant, energy source sector (e.g., agriculture, electricity), source type (point, line, area), and spatial modeling domain (nation, state, city, region). We demonstrate these metrics through a case study of fine particulate (PM 2.5 ) emissions from U.S. corn stover harvesting and local processing at various scales, representing steps in the biofuel production process. We model PM 2.5 formation in the atmosphere using a novel reduced-complexity chemical transport model called the Intervention Model for Air Pollution (InMAP). Through this case study, we present the first area-source PM 2.5 CFs that address the recommendations of several LCIA studies to establish spatially explicit CFs specific to an energy source sector or type. Overall, the framework developed in this work provides multiple new ways to consider the potential impacts of air emissions through spatially differentiated metrics.

09 BIOMASS FUELS↗
DOE OSTI2023

Application of NEAMS Multiphysics Framework for Species Tracking in Molten Salt Reactors

This report from Idaho National Laboratory (INL) summarizes the key modeling and simulation activities conducted under the Department of Energy (DOE) Molten Salt Reactor (MSR) Campaign during the Fiscal Year 2023 (FY23). The focus of the work was to leverage state-of-the-art modeling capabilities from the DOE Nuclear Energy Advanced Modeling and Simulation (NEAMS) codes to enable novel multiphysics and multiscale modeling and simulation of MSRs. Through collaboration with NEAMS code developers, advanced multiphysics analysis capabilities for MSR systems were demonstrated by coupling depletion, thermal-hydraulics, and thermochemistry into an innovative framework for chemical species transport in MSRs. As a result, the framework can track nuclides throughout their lifetimes in the core, from production (depletion) to advection throughout the salt volume (thermal-hydraulics) and off-gassing or precipitation outside of the salt (thermochemistry). This work supports the near-term deployment of MSRs by integrating the synergistic efforts between the DOE’s MSR Campaign and NEAMS program. The resulting framework will help better connect system design modelers with experimentalists to better understand and predict complex physical behaviors in MSRs. Researchers and MSR developers alike can now leverage these new modeling and simulation capabilities to perform novel analyses with applications including: • MSR dynamics during normal operational transients and accident scenarios • Off-gas system design and performance for fuel cycle and depletion analysis • Corrosion and active chemistry control for reactor component health and lifetime determination • Source term, decay heat and activity determination in accident scenarios • Special nuclear material accountancy and chemical forensic analysis for safeguards • Digital twin development of experiments and experimental reactor demonstrations • Measurement requirements for instrumentation and control design • Uncertainty and sensitivity analysis of missing data to inform future experimental data collection.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRS2001

High Resolution Radio Imaging of the Merging Galaxies NGC3256 and NGC4194

We present new 6cm and 4cm radio continuum images of the central regions of the merging galaxy systems NGC3256 and NGC4194. NGC3256 is imaged with a resolution of approx. 1 in. or approx. 190pc; NGC4194 is imaged with a resolution of approx. 0.3 in. or approx. 50pc. In both systems, we detect numerous compact radio sources embedded in more diffuse radio emission. We detect 65 compact sources in NGC3256 at 6cm and we detect 46 compact sources in NGC4194, both to a limiting luminosity of approx. 5 x 10(exp 18) W/ Hz or approx. 5 times the luminosity of Cas A. Most of the compact radio sources are loosely associated with active star forming regions but not with specific optical emission sources. Several compact radio sources in NGC3256 are near positions of compact X-ray sources detected by Lira et al.. In both NGC3256 and NGC4194, we are able to measure reliable spectral indices for the stronger sources. We find in NGC3256 approx. 20% have nominally flat radio spectral indices (indicating they are dominated by thermal radio emission from HII regions) while approx. 80% have nominally steep spectral indices (indicating they are dominated by nonthermal emission from supernova remnants). In NGC4194, half the compact radio sources have flat spectral indices and half have steep indices. For the flat-spectrum sources, we estimate the number of young massive stars and the associated ionized gas masses. For the steep-spectrum sources, we estimate supernova rates. We compare these results with those from other well-studied merging galaxy systems. We gratefully acknowledge use of the NRAO Very Large Array (VLA) and the VLA Archive. NRAO is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Neff, S. G.↗
DOE OSTI2018

Determining the Activation Network of Stainless Steel in Different Neutron Energy Regimes and Decay Scenarios Using Foil Activation Experiments and FISPACT-II Calculations

Here, the activation network of stainless steel grade 304 was investigated using foil activation experiments from two neutron sources, along with FISPACT-II calculations. A critical assembly and d+Be converter were used as neutron sources to cover different neutron energy ranges. Experimental production rates were compared against calculated values from FISPACT-II in order to validate neutron energy distributions and assess available cross-section data.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2016

X-RAY FLARING ACTIVITY OF MRK 421 IN THE FIRST HALF OF 2013

We present the results of the Swift and NuSTAR observations of the nearby BL Lac object Mrk 421 during 2013 January–June. The source exhibited a strong long-term variability in the 0.3–10 keV and 3–79 keV bands with the maximum-to-minimum daily-binned flux ratios of 22 and 95, respectively, in about 3 months, mainly due to unprecedented strong X-ray outbursts by more than an order of magnitude in both bands within 2 weeks in 2013 April when the 0.3–10 keV count rate exceeded the level of 200 cts s{sup −1} for the first time, and Mrk 421 became one of the brightest sources in the X-ray sky. The source was also very active on intra-day timescales, and it showed flux doubling and halving timescales of 1.16–7.20 hr and 1.04–3.54 hr, respectively. On some occasions, the flux varied by 4%–23% within 300–840 s. During this period, the source also exhibited some of the most extreme X-ray spectral variability ever reported for BL Lacs—the location of the synchrotron spectral energy distribution peak shifted from a few eV to ∼10 keV, and the photon index at 1 keV and curvature parameter varied on timescales from a few weeks down to intervals shorter than 1 ks. MAGIC and First G-APD Cherenkov Telescope observations also revealed a very strong very high energy (VHE) flare during April 11–17. The UV and HE γ -ray flares were much weaker compared to their X-ray counterparts, and they generally showed significantly stronger correlation with each other than with the X-ray fluxes.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS2017

Surface Ozone in the Colorado Northern Front Range and the Influence of Oil and Gas Development During FRAPPE/DISCOVER-AQ in Summer 2014

High mixing ratios of ozone (O3) in the northern Front Range (NFR) of Colorado are not limited to the urban Denver area but were also observed in rural areas where oil and gas activity is the primary source of O3 precursors. On individual days, oil and gas O3 precursors can contribute in excess of 30 ppb to O3 growth and can lead to exceedances of the EPA O3 National Ambient Air Quality Standard. Data used in this study were gathered from continuous surface O3 monitors for June-August 2013-2015 as well as additional flask measurements and mobile laboratories that were part of the FRAPPE/DISCOVER-AQ field campaign of July-August 2014. Overall observed O3 levels during the summer of 2014 were lower than in 2013, likely due to cooler and damper weather than an average summer. This study determined the median hourly surface O3 mixing ratio in the NFR on summer days with limited photochemical production to be approximately 45-55 ppb. Mobile laboratory and flask data collected on three days provide representative case studies of different O3 formation environments in and around Greeley, Colorado. Observations of several gases (including methane, ethane, CO, nitrous oxide) along with O3 are used to identify sources of O3 precursor emissions. A July 23 survey demonstrated low O3 (45-60 ppb) while August 3 and August 13 surveys recorded O3 levels of 75-80 ppb or more. August 3 exemplifies influence of moderate urban and high oil and gas O3 precursor emissions. August 13 demonstrates high oil and gas emissions, low agricultural emissions, and CO measurements that were well correlated with ethane from oil and gas, suggesting an oil and gas related activity as a NOx and O3 precursor source. Low isoprene levels indicated that they were not a significant contributor to O3 precursors measured during the case studies.

Pollution↗
DOE OSTI2015

Nuclear Material Detection by One-Short-Pulse-Laser-Driven Neutron Source

Covered in the PowerPoint presentation are the following areas: Motivation and requirements for active interrogation of nuclear material; laser-driven neutron source; neutron diagnostics; active interrogation of nuclear material; and, conclusions, remarks, and future works.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

NSLS-II Ground Vibration Stability Studies and Design Implementation

We report that next-generation synchrotron accelerator facilities pushing the envelope of resolution to just a few nanometers and possibly atomic scale (~1 nm) require extreme stability of their experimental setting. Such stability is greatly influenced by the background micro-seismic activity and natural disturbance sources that are present throughout the globe and the cultural, man-made noise stemming from traffic on nearby highways and railways, operating machinery, and other activities. Defenses against such negatively impacting environment include smart conventional design of facilities, isolation of experiments, careful consideration of the selected site by providing ample distance from sources or protection by depth and, most importantly, qualification/quantification of the ground vibration environment both in terms of amplitude and spectral characteristics. Qualification and quantification of the site-specific noise environment may be utilized in the implementation of defense features in the design of the facility and high-sensitivity experiments. The performance is measured by the adherence to specific stability criteria that are ever-demanding, given the nature of the experiments that are sought where resolution down to a few nanometers is required. Furthermore, the selection of the optimal site and the quantification of the unavoidable background noise are important aspects to be considered in assessing the performance of such facilities.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Impacts of The Wetland Sedge Carex aquatilis on Microbial Community and Methane Metabolisms

Microbial activity in the soil of wetlands is responsible for the emission of more methane to the atmosphere than all other natural sources combined. This microbial activity is heavily impacted by plant roots, which influence the microbial community by exuding organic compounds and by leaking oxygen into an otherwise anoxic environment. This study compared the microbial communities of planted and unplanted wetland soil from an Alaskan bog to elucidate how plant growth influences populations and metabolisms of methanogens and methanotrophs. A common boreal wetland sedge, Carex aquatilis, was grown in the laboratory and DNA samples were sequenced from the rhizosphere, unplanted bulk soil, and a simulated rhizosphere with oxygen input but no organic carbon. The abundance of both methanogens and methanotrophs were positively correlated with methane emissions. Among the methanotrophs, both aerobic and anaerobic methane oxidizing microbes were more common in the rhizosphere of mature plants than in unplanted soil, while facultative methanotrophs capable of utilizing either methane or other molecules became relatively less common. Furthermore, these trends indicate that the roots in this experiment created an environment which favored highly specialized microbial metabolisms over generalist approaches. One aspect of this specialized microbiome is the presence of both aerobic and anaerobic metabolisms, which indicates that oxygen is present but is a limiting resource controlling competition.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

‘ Candidatus Liberibacter asiaticus’-Encoded BCP Peroxiredoxin Suppresses Lipopolysaccharide-Mediated Defense Signaling and Nitrosative Stress In Planta

The lipopolysaccharides (LPS) of gram-negative bacteria trigger a nitrosative and oxidative burst in both animals and plants during pathogen invasion. Liberibacter crescens strain BT-1 is a surrogate for functional genomic studies of the uncultured pathogenic ‘Candidatus Liberibacter’ spp. that are associated with severe diseases such as citrus greening and potato zebra chip. Structural determination of L. crescens LPS revealed the presence of a very long chain fatty acid modification. L. crescens LPS pretreatment suppressed growth of Xanthomonas perforans on nonhost tobacco (Nicotiana benthamiana) and X. citri subsp. citri on host orange (Citrus sinensis), confirming bioactivity of L. crescens LPS in activation of systemic acquired resistance (SAR). L. crescens LPS elicited a rapid burst of nitric oxide (NO) in suspension cultured tobacco cells. Pharmacological inhibitor assays confirmed that arginine-utilizing NO synthase (NOS) activity was the primary source of NO generation elicited by L. crescens LPS. LPS treatment also resulted in biological markers of NO-mediated SAR activation, including an increase in the glutathione pool, callose deposition, and activation of the salicylic acid and azelaic acid (AzA) signaling networks. Transient expression of ‘Ca. L. asiaticus’ bacterioferritin comigratory protein (BCP) peroxiredoxin in tobacco compromised AzA signaling, a prerequisite for LPS-triggered SAR. Western blot analyses revealed that ‘Ca. L. asiaticus’ BCP peroxiredoxin prevented peroxynitrite-mediated tyrosine nitration in tobacco. ‘Ca. L. asiaticus’ BCP peroxiredoxin (i) attenuates NO-mediated SAR signaling and (ii) scavenges peroxynitrite radicals, which would facilitate repetitive cycles of ‘Ca. L. asiaticus’ acquisition and transmission by fecund psyllids throughout the limited flush period in citrus.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

Assessing modifications to the Abdul-Razzak and Ghan aerosol activation parameterization (version ARG2000) to improve simulated aerosol–cloud radiative effects in the UK Met Office Unified Model (UM version 13.0)

The representation of aerosol activation is a key source of uncertainty in global composition-climate model simulations of aerosol–cloud interactions. The Abdul-Razzak and Ghan (ARG) activation parameterization is used in several global and regional models that employ modal aerosol microphysics schemes. In this study, we investigate the ability of the ARG parameterization to reproduce simulations with a cloud parcel model and find its performance is sensitive to the geometric standard deviations (widths) of the lognormal aerosol modes. We recommend adjustments to three constant parameters in the ARG equations, which improve the performance of the parameterization for small mode widths and its ability to simulate activation in polluted conditions. For the accumulation mode width of 1.4 used in the Met Office Unified Model (UM), the modifications decrease the mean bias in the activated fraction of aerosols compared to a cloud parcel model from −6.6 % to +1.2 %. We implemented the improvements in the UM and compared simulated global cloud droplet concentrations with satellite observations. The simulated cloud radiative effect changes by −1.43 W m −2 (6 %) and aerosol indirect radiative forcing over the industrial period changes by −0.10 W m −2 (10 %).

Ghosh, Pratapaditya [Carnegie Mellon University, P↗
DOE OSTI2013

Safety and Security of Radioactive Sealed and Disused/Orphan Sources in Ukraine - German Contribution - 13359

Within the scope of 'Nuclear Security of Radioactive Sources', the German government implemented the modernization of Ukrainian State Production Company's transport and storage facility for radioactive sources (TSF) in Kiev. The overall management of optimizing the physical protection of the storage facility (including the construction of a hot cell for handling the radioactive sources) is currently carried out by the German Federal Foreign Office (AA). AA jointly have assigned Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Germany's leading expert institution in the area of nuclear safety and waste management, to implement the project and to ensure transparency by financial and technical monitoring. Sealed radioactive sources are widely used in industry, medicine and research. Their life cycle starts with the production and finally ends with the interim/long-term storage of the disused sources. In Ukraine, IZOTOP is responsible for all radioactive sources throughout their life cycle. IZOTOP's transport and storage facility (TSF) is the only Ukrainian storage facility for factory-fresh radioactive sources up to an activity of about 1 million Ci (3.7 1016 Bq). The TSF is specially designed for the storage and handling of radioactive sources. Storage began in 1968, and is licensed by the Ukrainian state authorities. Beside the outdated state of TSF's physical protection and the vulnerability of the facility linked with it, the lack of a hot cell for handling and repacking radioactive sources on the site itself represents an additional potential hazard. The project, financed by the German Federal Foreign Office, aims to significantly improve the security of radioactive sources during their storage and handling at the TSF site. Main tasks of the project are a) the modernization of the physical protection of the TSF itself in order to prevent any unauthorized access to radioactive sources as well as b) the construction of a hot cell to reduce the number of transports of radioactive sources within the city of Kiev. In future, the new established hot cell at IZOTOP's transport and storage facility will be useful for identification and characterization of orphan/disused radioactive sources. The projects implemented are performed in accordance with international recommendations (e. g. IAEA) and national normative documents and will make a crucial contribution towards an improved safety and security management of radioactive sources in Ukraine. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1984

Lightning activity and severe storm structure

Space-time mapping of VHF sources from four severe storms on June 19, 1980 reveals that lightning processes for cloud-to-ground (CG) and large intracloud (IC) flashes are confined to an altitude below about 10 km and closely associated with the central regions of high reflectivity. Another class of IC flashes produces a splattering of sources within the storms' main electrically active volumes and also within the large divergent wind canopy aloft. There is no apparent temporal association between the small high altitude IC flashes that occur almost continuously and the large IC and CG flashes that occur sporadically in the lower portions of storms.

Taylor, W. L.↗
DOE OSTI2013

Regulatory framework for NORM residues in Belgium

The Belgian radiation protection authority (Federal Agency for Nuclear Control - FANC) has published in March 2013 a decree regulating the acceptance of NORM residues by nonradioactive waste treatment facilities. This regulation is based on the concept of 'work activities involving natural radiation sources' in the sense of article 40 of the 96/29/EURATOM directive. The disposal or processing facilities which accept NORM residues with an activity concentration above a generic exemption level will be considered as 'work activities' and submitted to declaration according to the Belgian radiation protection regulations. On basis of this declaration, specific acceptance criteria for the different types of processing/ disposal of the residues (disposal on landfill, recycling into building materials, etc.) are imposed. FANC has drafted guidelines for these acceptance criteria. A methodological guide for the operators of the concerned facilities was also published. Moreover, sites where significant quantities of NORM residues are or have been disposed, are subjected to an environmental monitoring in the framework of the national program of radiological surveillance of FANC. FANC also introduced in its regulations the concept of anthropogenic radon-prone areas: e.g. former phosphogypsum stacks have been defined as anthropogenic radon-prone areas, which allows some form of regulatory control of these sites. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1990

H2 line emission in three Seyfert nuclei: Evidence against UV-excitation

Line emission from vibrationally excited molecular hydrogen has been detected in a considerable number of active galactic nuclei (AGNs), including those generally believed to contain compact and luminous central engines (e.g., Seyfert nuclei) and those in which the luminosity is believed to arise from massive bursts of star formation (starburst nuclei). In most of these AGNs, only the bright 1-0 S(1) line (rest wavelength 2.12 microns) has been searched for and detected to date. Line-emitting H2 can be excited directly either by energetic collisions created by shock waves or by absorption of UV radiation. Each of these excitation mechanisms has been clearly identified in galactic and extragalactic regions. In active galactic nuclei strong sources of UV and (in some case) x rays are present. If the nuclear molecular matter is quiescent (i.e., isolated from the active nucleus and not set into motion by episodes of star formation) the H2 line emission will be dominated by fluorescence, or possibly by thermal emission due to heating by x rays (Krolik, this conference). However, it is expected or indeed observed that a significant fraction of the interstellar medium in and near these nuclei is undergoing rapid motions; either generated by the central engine or by a nuclear starburst, which are capable of producing strong shock phenomena in nearby molecular gas. Thus, a priori it is not obvious which mechanism is responsible for the H2 line emission from the nucleus of an active galaxy.

Geballe, T. R.↗
DOE OSTI2022

A study on the clustering properties of radio-selected sources in the Lockman Hole region at 325 MHz

Studying the spatial distribution of extragalactic source populations is vital in understanding the matter distribution in the Universe. It also enables understanding the cosmological evolution of dark matter density fields and the relationship between dark matter and luminous matter. Clustering studies are also required for EoR foreground studies since it affects the relevant angular scales. This paper investigates the angular and spatial clustering properties and the bias parameter of radio-selected sources in the Lockman Hole field at 325 MHz. The data probes sources with fluxes ≳0.3 mJy within a radius of 1.8° around the phase centre of a 6° × 6° mosaic. Based on their radio luminosity, the sources are classified into Active Galactic Nuclei (AGNs) and Star-Forming Galaxies (SFGs). Clustering and bias parameters are determined for the combined populations and the classified sources. The spatial correlation length and the bias of AGNs are greater than SFGs- indicating that more massive haloes host the former. This study is the first reported estimate of the clustering property of sources at 325 MHz, intermediate between the pre-existing studies at high and low-frequency bands. It also probes a well-studied deep field at an unexplored frequency with moderate depth and area. Clustering studies require such observations along different lines of sight, with various fields and data sets across frequencies to avoid cosmic variance and systematics. Thus, an extragalactic deep field has been studied in this work to contribute to this knowledge.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

Self-induced steady-state magnetic field in the negative ion sources with localized rf power deposition

The study is in the scope of a recent activity on modeling of SPIDER (Source for Production of Ions of Deuterium Extracted from RF plasma) which is under development regarding the neutral beam injection heating system of ITER. The regime of non-ambipolarity in the source, established before, is completed here by introducing in the model the steady state magnetic field, self-induced in the discharge due to the dc current flowing in it. Strong changes in the discharge structure are reported.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2013

Characterization of Persistent Volatile Contaminant Sources in the Vadose Zone

Remediation activities over time will alter the subsurface distribution of contaminants and likely create significant changes in the source-zone architecture. A field method was demonstrated for use of data collected from multiple individual soil vapor extraction (SVE) system well tests to locate and characterize the distribution of persistent VOC sources in the vadose zone. Operational data collected at the Department of Energy’s Hanford site were used to examine source zone alteration over time due to SVE operation and to illustrate the source-zone characterization approach. Individual well test results confirmed a heterogeneous distribution of permeability and contaminant mass discharge throughout the vadose zone. The trends in mass discharge and concentration were analyzed to determine the location and extent of the primary source zone within a lower-permeability unit at the site. This information is useful to evaluate the performance of SVE operations, and support decisions concerning system alteration or closure based on risk assessments of the impact of vadose-zone sources on groundwater contamination or vapor intrusion.

carbon tetrachloride↗