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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 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Gas stream analysis using voltage-current time differential operation of electrochemical sensors

A method for analysis of a gas stream. The method includes identifying an affected region of an affected waveform signal corresponding to at least one characteristic of the gas stream. The method also includes calculating a voltage-current time differential between the affected region of the affected waveform signal and a corresponding region of an original waveform signal. The affected region and the corresponding region of the waveform signals have a sensitivity specific to the at least one characteristic of the gas stream. The method also includes generating a value for the at least one characteristic of the gas stream based on the calculated voltage-current time differential.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2019

Continuously-operable flow stream processing system and method

A continuously-operable flow stream processing system and method has two or more fluid processing media arranged in a fluid conduit network to provide alternate flow paths for a flow stream to be processed (e.g. filtered). Valves and other flow control devices, e.g. controller module and sensors, are used to redirect the flow stream from one or more service-needed fluid processing media to service-ready fluid processing media without taking the system offline to remove, repair, replace, clean in situ, or otherwise service the service-needed fluid processing media, so that the system may operate continuously to process the flow stream without stoppage. Redirection into alternative flow paths and media may be automatically implemented based on a predetermined threshold or trigger condition, such as may be detected by sensors directly or indirectly monitoring media condition.

42 ENGINEERING↗
DOE OSTI2020

Biocatalysts for conversion of thermochemical waste streams

Disclosed herein are microorganisms that have enhanced tolerance to toxic compounds found in thermochemical waste streams. Methods of utilizing carbon found in waste streams are also disclosed. Also presented herein are methods for detoxifying waste streams and methods of bioconversion of toxic waste stream materials into useful products.

Jayakody, Thelhawadigedara Lahiru Niroshan↗
DOE OSTI2020

A Visual Analytics Framework for Reviewing Streaming Performance Data

Understanding and tuning the performance of extreme-scale parallel computing systems demands a streaming approach due to the computational cost of applying offline algorithms to vast amounts of performance log data. Analyzing large streaming data is challenging because the rate of receiving data and limited time to comprehend data make it difficult for the analysts to sufficiently examine the data without missing important changes or patterns. To support streaming data analysis, we introduce a visual analytic framework comprising of three modules: data management, analysis, and interactive visualization. The data management module collects various computing and communication performance metrics from the monitored system using streaming data processing techniques and feeds the data to the other two modules. The analysis module automatically identifies important changes and patterns at the required latency. In particular, we introduce a set of online and progressive analysis methods for not only controlling the computational costs but also helping analysts better follow the critical aspects of the analysis results. Finally, the interactive visualization module provides the analysts with a coherent view of the changes and patterns in the continuously captured performance data. Through a multi-faceted case study on performance analysis of parallel discrete-event simulation, we demonstrate the effectiveness of our framework for identifying bottlenecks and locating outliers.

Human-centered computing↗
DOE OSTI2022

Methods for the separation of CO2 from a gas stream

Disclosed herein are 2-stage membrane separation methods for capturing CO2 from a feed gas. The methods can employ two selectively permeable membranes, which may be the same or different. The selectively permeable membrane can have a carbon dioxide permeance of from 500 to 3000 GPU at 57° C. and 1 atm feed pressure and a carbon dioxide:nitrogen selectivity of from 10 to 1000 at 57° C. and 1 atm feed pressure. High pressure ratios across the membranes can be achieved by compressing the feed gas to a high pressure, by using vacuum pumps to create a lowered pressure on the permeate side of the membrane, by using a sweep stream, or a combination thereof. When a sweep stream is used, the sweep stream may include a portion of the retentate gas stream obtained from the retentate side of one or more of the membranes used.

Ho, W. S. Winston↗
DOE OSTI2023

Two-phase separator device for removing condensate or particulate from a gas stream

This disclosure provides a two-phase separator device for separating condensate or particulate from a gas stream. In some implementations, the separator device removes water from air and may operate under micro-gravity conditions. The gas stream flows through the two-phase separator device and passes through a rotatable vane assembly along a flow path without being redirected in another flow path. Condensate or particulate in the gas stream is impacted by a plurality of vanes of the rotatable vane assembly, and the condensate is captured by features formed within the plurality of vanes. The captured condensate is accelerated radially outwardly along the each of the plurality of vanes towards a sloped inner wall, and further moved along the sloped inner wall in a direction against the flow path of the gas stream during rotation.

Cognata, Thomas↗
DOE OSTI2015

Not all Greater-Than-Class c (GTCC) waste streams are created equal - 15373

Greater-Than-Class C (GTCC) waste is a low level radioactive waste (LLRW) that exceeds the Class C concentration limits in Part 61.55 of Title 10 of the Code of Federal Regulations. Typically, this waste consists of irradiated metal components from reactors such as core shrouds, support plates, and core barrels, as well as filters and resins from reactor operations and decommissioning. Sealed sources used at hospitals, medical schools, research facilities, and universities can also be classified as GTCC waste. A third category, 'Other Waste', consisting of contaminated equipment, rubble, scrap metal, filters, soil, and solidified sludges may be classified as GTCC waste based on their differing radionuclides and concentration levels. The Low-Level Radioactive Waste Policy Amendments Act of 1985 requires the Federal Government to take responsibility for the disposal of GTCC waste. All GTCC waste created from U.S. Nuclear Regulatory Commission (NRC) licensed activities, under the Atomic Energy Act of 1954, as amended, must be disposed of in an NRC licensed facility that has been determined to be adequate to protect public health and safety. Information from Argonne National Laboratory's supplemental report on GTCC waste from 2010 anticipates that the total volume of GTCC waste will be approximately 8,800 m{sup 3} (311,000 ft{sup 3}) and the projected activity of that waste will be 5.92 x 10{sup 6} TBq (160 MCi) with generation activities ending in 2083. Currently, there is no pathway for the disposal of GTCC waste in the United States. A performance-based approach may be used to subdivide GTCC waste into various waste streams by reviewing the characteristics of GTCC waste with its associated hazards. Characteristics of GTCC waste include half-life and concentration. In creating the 10 CFR Part 61 waste classification tables, which define GTCC concentrations, a number of assumptions were made regarding waste inventory and exposure scenarios for the inadvertent intruder for a generic LLRW disposal facility. The findings from other exposure scenarios (e.g., construction, agriculture, well drilling), together with the findings from evaluations of radiological characteristics of GTCC, could be used as part of a performance-based approach for categorizing GTCC waste. The findings may determine that some GTCC waste streams will be closer in characteristics to Class C waste, while other GTCC waste streams will have characteristics similar to high-level waste and may require a higher degree of isolation from the public. The application of a site-specific and performance-based approach to GTCC waste stream characterization could assist the NRC in developing specific technical requirements for future disposal of various types of GTCC waste. Examples of part of a performance-based approach that examine and evaluate the radiological characteristics of GTCC waste will be presented. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Application of SIAL{sup R} Solidification Technology for Processing of Problematic Waste Streams - 18267

SIAL{sup R} is a proven, safe, cost-effective and licensed waste solidification technology that has been used successfully for 20 years in Slovakia and the Czech Republic for processing of various problematic radioactive waste streams. This abstract presents and summarises the most interesting performance records of the SIAL{sup R} geopolymer solidification technology, the applied mobile devices as well as the characteristics of final products. Radioactive waste solidification into matrix SIAL{sup R} is based on polycondensation of inorganic aluminosilicate components with chemical composition similar to average cement. The main components of matrix SIAL{sup R} are natural inorganic raw materials containing SiO{sub 2}, Al{sub 2}O{sub 3}, CaO, MgO, Na{sub 2}O, K{sub 2}O, Fe{sub 2}O{sub 3}, and TiO{sub 2}. The treatment/solidification process is modified for individual radioactive streams with different compositions. To determine the most appropriate composition, the SIAL{sup R} application technology is laboratory tested on real samples of each individual waste stream identified for solidification. Then an appropriate mixture of aluminosilicate composition and other inorganic compounds is defined for a given solidification application. When determining the most appropriate mixture, other requirements are taken into consideration: maximum dose rate on the drum with solidified product, mass, volume, alpha radionuclide content in the final product, need for a waste's dewatering before solidification, dry matter content in the solidification product as well as other specific waste acceptance criteria (i.e., compressive strength, leachability, diffusion coefficients, radiation stability, biodegradability of matrix, distribution and partition coefficients, influence of frost and water presence to the product stability including long term physical stability in water, dustiness, flammability, time dependence of compression strength and water reduction, product homogeneity and also radiolytic G-value for hydrogen release, GH{sub 2}). The Amec Foster Wheeler baseline approach to implementing the SIAL{sup R} waste treatment process is structured on three steps - waste characterization, waste retrieval and pre-treatment and at last the solidification of pre-treated waste itself. The equipment used for the solidification process is relatively small, lightweight and designed for the specific application on site, directly 'in situ' or local to the tanks storing the sludge's/resins/other waste streams. This mitigates the problems normally experienced by transferring sticky, tight waste through long pipes. The equipment is normally 'tailor-made' to take into account the real space conditions and other existing facility requirements. At Bohunice and Dukovany sites, the facilities for encapsulation were designed to occupy existing areas of the plants in close proximity to the tanks where the waste was being stored. This allowed for the removal of the waste using Remote Operated Vehicles and for the waste to be immediately treated on site without the need for transportation thus saving both, time and resource. To date, SIAL{sup R} has been used successfully to immobilize approximately 2 x 10{sup 6} kg of waste which includes sludge, resin, crystalline borates and contaminated organic waste from Bohunice and Mochovce, Slovakia and approximately 300 m{sup 3} of spent ion exchange resins and sludge from tanks on site at the Dukovany NPP (Nuclear Power Plant) in the Czech Republic. The technology now has a track record of over 20 years which includes on-going research and development. The International missions WANO (the World Association of Nuclear Operators) and OSART (the Operational Safety Review Team) evaluated the SIAL{sup R} matrix technology at Dukovany NPP as an example of good practice. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Development of a Methodology to Assess the Impact of Non-Conventional Waste Streams Following a Radiological Incident - 18271

The Environmental Protection Agency's (EPA's) Waste Estimation Support Tool (WEST) is a Geographic Information System (GIS)-based decision support tool for estimating waste generated from remediation and cleanup activities following a radiological incident. WEST uses the Federal Emergency Management Agency's (FEMA's) Hazus-MH software's infrastructure information combined with image classification capabilities to estimate the quantity of waste and debris that may result from a radiological incident. WEST can be used to create customized decontamination strategies that allow end-users to evaluate different means of decontamination and how those strategies may impact the resulting waste stream in each geographical locality. This capability can potentially reduce the response/recovery time frame and cost. One of the key observations from past applications of WEST is that planning scenarios are site-specific, especially when dealing with chemical, biological, radiological, or nuclear (CBRN) waste management issues. Furthermore, site-specific issues are not limited to resource limitations or response bottlenecks but should also account for differences in an area's geography and urban footprint, a phenomenon observed during the Fukushima response. For instance, a recent WEST case study found that the amount of waste generated per unit of affected area, for a given decontamination approach, is largely a function of the building surface area in the affected area (relative to the ground surfaces). However, differences in the geometry and density of contaminated objects in the landscape may impact the amount and characteristics of the waste stream. Although buildings typically constitute a large portion of the surface area in urban environments, other objects such as vehicles and trees can be just as prominent. For example, seasonal changes in the amount of foliage present can alter the non-structural surface area calculated for an area like New York City by 20-30%. Very little is known about the impact that these non-conventional waste streams have on overall remediation strategies, or to what extent differences in characteristics of urban versus rural environments, traffic activities, or seasonal variations may have on these factors. This paper will present the proposed methodology to incorporate into WEST the impacts that niche, nonconventional waste streams might have from rural and urban environments following a nuclear power plant incident or detonation of a radiological dispersal device or improvised nuclear device. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Panel Session 90: US DOE Mixed Waste: Proposals for Dealing with Problematic Waste Streams and Policy Changes

This panel focused on generation and management of low level and mixed low-level radioactive wastes, challenges for disposition, innovative solutions applied at DOE sites, and collaboration among sites to ensure that waste disposition pathways are understood. In addition, potential policy initiatives were discussed including depleted uranium, elemental mercury, and treatment of legacy mixed waste components. As part of the introduction, Theresa Kliczewski provided an overview of why this panel is relevant: problematic mixed waste streams still exist across the DOE cleanup complex. Theresa noted that the DOE EM Headquarters Office of Waste and Materials Management (EM-4.2), for which she is employed with, continues to work with the DOE cleanup sites on a path forward for these problematic mixed waste streams. As part of this effort, EM-4.2 requested that the Energy Facility Contractors Group (EFCOG) perform a review of all the DOE sites problematic mixed waste streams. Panelists with presentations: Challenging Waste Streams: Disposition of Depleted Uranium Oxide Conversion Product (Douglas Tonkay); EFCOG WMWG Challenging Waste Subgroup (Tammy Monday); Mercury Waste Challenges (John Wrapp); Legacy Large Mixed Waste Components (Kalli Shupe)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Concentration of Kr from Simulated Dissolver Off-Gas Streams Utilizing a Solid Sorbent, HZ-PAN

Idaho National Laboratory (INL) has developed and tested engineered sorbents to separate and capture volatile fission products such iodine, xenon (Xe), and krypton (Kr) from off-gas streams. A study was conducted using a solid sorbent, HZ-PAN, to concentrate Kr from a simulated dissolver off-gas stream. The study demonstrates that four adsorption-desorption cycles can transform a 150 ppmv Kr stream into a 37.5% Kr stream, an overall concentration factor of 2497.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Characterization of Coal Refuse Sites in West Virginia: Stream Loss, Volume Estimation, and Land Cover Analysis for Restoration Feasibility

Coal refuse disposal across Appalachia has resulted in widespread environmental degradation, including stream burial, landscape destabilization, and long-term hydrologic impacts. This study provides a GIS-based spatial characterization of 623 coal refuse sites in West Virginia, evaluating their potential for ecological and economic restoration. Stream loss was quantified through digitization of historic topographic maps, revealing over 194,500 meters of historically present streams lost, with 105,000 meters directly buried beneath refuse piles. Volume estimation using empirical Bayesian kriging and modern LiDAR surfaces indicated approximately 1.96 billion cubic meters of deposited refuse. Land cover analysis based on NAIP-derived classification showed that 48% of the total site area was forested, while 15% remained barren. These results highlight not only the environmental footprint of legacy refuse deposits but also their potential for restoration through stream daylighting and beneficial reuse. Emerging opportunities, including rare earth element recovery and mitigation banking, may offer economic incentives to facilitate reclamation. This work establishes a spatial framework to prioritize refuse sites for restoration, balancing ecological uplift with feasible material management strategies.

58 GEOSCIENCES↗
DOE OSTI2025

Forecasting Dark Matter Subhalo Constraints from Stellar Streams using Implicit Likelihood Inference

The evidence for dark matter (DM) remains compelling, although attempts to understand its particle nature remain inconclusive. One promising method to study DM is detecting DM subhalos through their gravitational interactions with stellar streams. In this study, we apply Neural Posterior Estimation (NPE) to constrain subhalo interaction parameters, including mass, scale radius, velocity, and encounter geometry, from stellar stream kinematics. We generate particle spray simulations based on the Lagrange Cloud stripping technique, focusing on the ATLAS-Aliqa Uma stream as a test case. We train multiple NPE models across multiple observational scenarios, quantifying how kinematic completeness affects inference and forecasting constraints from upcoming surveys including LSST, 4MOST, and 10-year Gaia data. Our results demonstrate that NPE can produce accurate and well-calibrated posteriors. In the idealized case with full 6D coordinates, we achieve subhalo mass uncertainties of 15-20% for a $10^7 \, \mathrm{M_\odot}$ subhalo, with 5D coordinates (excluding radial velocities) achieving similar performance. Under realistic observational conditions, mass uncertainties range from 50% (present-day) to 20-40% (future scenarios), with comparable performance between the photometric-only LSST sample and a smaller sample that includes Gaia proper motions and 4MOST radial velocities. Most notably, we find that velocity bimodality emerges when phase space is poorly sampled, whether due to missing kinematic information or limited stellar tracers. Combining large photometric samples with targeted spectroscopic follow-up can effectively resolves this degeneracy. These results demonstrate the power of implicit likelihood inference for optimizing stellar stream observational strategies and forecasting DM subhalo constraints from upcoming surveys.

Nguyen, Tri [Northwestern U. (main); SkAI, Chicago↗
DOE OSTI2014

Waste Stream Treatment and Waste Form Fabrication for Pyroprocessing of Used Nuclear Fuel

This report summarizes treatment and waste form options being evaluated for waste streams resulting from the electrochemical/pyrometallurgical (pyro ) processing of used oxide nuclear fuel. The technologies that are described are South Korean (Republic of Korea – ROK) and United States of America (US) ‘centric’ in the approach to treating pyroprocessing wastes and are based on the decade long collaborations between US and ROK researchers. Some of the general and advanced technologies described in this report will be demonstrated during the Integrated Recycle Test (IRT) to be conducted as a part of the Joint Fuel Cycle Study (JFCS) collaboration between US Department of Energy (DOE) and ROK national laboratories. The JFCS means to specifically address and evaluated the technological, economic, and safe guard issues associated with the treatment of used nuclear fuel by pyroprocessing. The IRT will involve the processing of commercial, used oxide fuel to recover uranium and transuranics. The recovered transuranics will then be fabricated into metallic fuel and irradiated to transmutate, or burn the transuranic elements to shorter lived radionuclides. In addition, the various process streams will be evaluated and tested for fission product removal, electrolytic salt recycle, minimization of actinide loss to waste streams and waste form fabrication and characterization. This report specifically addresses the production and testing of those waste forms to demonstrate their compatibility with treatment options and suitability for disposal.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

Three-Dimensional Flow Analysis Methodology for Assessing Stream Stability and Channel Migration

Increases in the frequency and magnitude of weather events that deviate significantly from average are being observed both globally and in the U.S. Adaptation strategies need to account for and mitigate increased risks to transportation infrastructure that result from more extreme weather. The present study is a part of a project that covers a sensitivity study of the potential impacts of increases in stream flows due to rain events and floods on an active section of the Maple River near Iowa Highway 175 and Danbury, Iowa, which is shown. This study focuses on the use of advanced three-dimensional (3D) computational fluid dynamics (CFD) techniques to enhance the assessment of increased risks to stream stability of a section of the Maple River that may erode into Iowa Highway 175. The methodology developed and presented can be applied to a wide variety of streams and rivers that may face increased risk of migration due to changes in weather patterns and severity of weather events. The Maple River is a laterally active channel flowing through agricultural land that has migrated several hundred feet in recent decades and is currently within approximately 100 feet of the Highway 175 Right-of-Way. In addition to the near-term threat to the highway from the closest river meander, there is also a concern that other river meanders could develop into longer-term threats, especially if increasing intensity or frequency of rain events increase the rate of meander development and channel migration by changing the long-term hydrology of the Maple River.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Low flow characteristics for regulated and unregulated streams in North Carolina and prediction using climate signals

In this work, low flow statistics of regulated and unregulated streams in the state of North Carolina were updated with streamflow data through 2019. About 22% of the streams considered show a significant downward trend, but considerable low-frequency variability confounding trends. The relationship between regional index time series of groundwater-depth low flow and the Atlantic Multidecadal Oscillation (AMO) was examined to determine whether low-frequency climate modes can account for the long-term pattern in low flows. Consequently, a significant correlation was found between AMO and groundwater-depth low flow, such that positive AMO is associated with lower groundwater-depth low flow and vice versa, particularly for the Piedmont region. Predictive equations for annual low flows at the ecoregion level shows that springtime average streamflow and AMO were selected as the primary predictors of low flow for coastal and Piedmont regions, whereas springtime average streamflow and the November–December–January average Oceanic Niño Index were used as the primary predictors for the mountain region. The relative root mean square error (RMSE) of the disaggregated predictions to US Geologic Survey gauge locations was <23% at 79% of the stations, between 24% and 43% at 10% of the stations, and greater than 44% at 1% of the stations. The remaining 10% of stations showed large RMSEs. This latter percentage is characterized by smaller drainage basins and intermittent flows, suggesting the prediction models are not applicable to drainage basins smaller than roughly 20 square km and intermittent streams.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Drivers of nitrogen transfer in stream food webs across continents

Studies of trophic-level material and energy transfers are central to ecology. The use of isotopic tracers has now made it possible to measure trophic transfer efficiencies of important nutrients and to better understand how these materials move through food webs. We analyzed data from thirteen 15 N-ammonium tracer addition experiments to quantify N transfer from basal resources to animals in headwater streams with varying physical, chemical, and biological features. N transfer efficiencies from primary uptake compartments (PUCs; heterotrophic microorganisms and primary producers) to primary consumers was lower (mean: 11.5%, range: <1%-43%) than N transfer efficiencies from primary consumers to predators (mean: 80%, range: 5%- >100%). Total N transferred (as a rate) was greater in streams with open compared to closed canopies and overall N transfer efficiency generally followed a similar pattern, although was not statistically significant. We used principal component analysis to condense a suite of site characteristics into two environmental components. Total N uptake rates among trophic levels were best predicted by the component that was correlated with latitude, DIN:SRP, GPP:ER, and % canopy cover. N transfer efficiency did not respond consistently to environmental variables. Here, our results suggest that canopy cover influences N movement through stream food webs because light availability and primary production facilitate N transfer to higher trophic levels.

15N↗
DOE OSTI2015

A Review of Major Non-Power-Related Carbon Dioxide Stream Compositions

A critical component in the assessment of long-term risk from geologic sequestration of carbon dioxide (CO2) is the ability to predict mineralogical and geochemical changes within storage reservoirs as a result of rock-brine-CO2 reactions. Impurities and/or other constituents in CO2 source streams selected for sequestration can affect both the chemical and physical (e.g., density, viscosity, interfacial tension) properties of CO2 in the deep subsurface. The nature and concentrations of these impurities are a function of both the industrial source(s) of CO2, as well as the carbon capture technology used to extract the CO2 and produce a concentrated stream for subsurface injection and geologic sequestration. This article reviews the relative concentrations of CO2 and other constituents in exhaust gases from major non-energy-related industrial sources of CO2. Assuming that carbon capture technology would remove most of the incondensable gases N2, O2, and Ar, leaving SO2 and NOx as the main impurities, the authors then summarize the relative proportions of the remaining impurities assumed to be present in CO2 source streams that could be targeted for geologic sequestration. The summary is presented relative to five potential sources of CO2: 1) Flue Gas with Flue Gas Desulfurization, 2) Combustion Stack from Coke Production, 3) Portland Cement Kilns, 4) Natural Gas Combustion, and 5) Lime Production.

Carbon dioxide, CO2 source streams, CO2 impurities↗