Search NASA⌕ Search

SEARCH · Search NASA

Results for “Data evaluation”

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 739 records · Page 41
All sourcesNASA NTRSDOE OSTI
NASA NTRS2020

A Post-2013 Dropoff in Total Ozone at a Third of Global Ozonesonde Stations: Electrochemical Concentration Cell Instrument Artifacts?

An international effort to improve ozonesonde data quality and to reevaluate historical recordshas made significant improvements in the accuracy of global network data. However, between 2014 and2016, ozonesonde total column ozone (TCO; O3) at 14 of 37 regularly reporting stations exhibited a suddendropoff relative to satellite measurements. The ozonesonde TCO drop is 3–7% compared to satellite andground‐based TCO, and 5–10% or more compared to satellite stratospheric O3profiles, compromising theuse of recent data for trends, although they remain reliable for other uses. Hardware changes in theozonesonde instrument are likely a major factor in the O3dropoff, but no single property of the ozonesondeexplains thefindings. The bias remains in recent data. Research to understand the dropoff is in progress; thisletter is intended as a caution to users of the data. Ourfindings underscore the importance of regularozonesonde data evaluation.

ozonesonde TCO drop↗
NASA NTRSDate not supplied

On-orbit/On-surface Servicing, Assembly, and Manufacturing (OSAM) Architecture Simulation System (OASiS)

On-orbit/on-surface servicing, assembly, and manufacturing (OSAM) –recently renamed“in-space servicing, assembly, and manufacturing”(ISAM) –will aid in the development of vital research-enabling structuresin space, such as the In-space Assembled Telescope, the Lunar Gateway, and the Lunar Safe Haven. As these structures become larger and more complex, developers will need new methods for verifying and validating their OSAM mission architectures at full-scale prior to launch, without paying for extensive facility upgrades or additional hardware prototypes. Under the OSAM Architecture Simulation System (OASiS) project, modular OSAM modeling and simulation capabilities were developed to help rapidly prototype and evaluate OSAM technologies and operational concepts.Theywerethenusedto demonstrate and evaluate data from the simulation of a simpleOSAM operation against ananaloghardware setup. Using collected test data, the teamevaluatedthe accuracy of the simulation environment against the behavior of real hardwareandgainedinsight on how to further improve OSAM modeling and simulation. With thesenewcapabilities and many more to come, developers will be able to test complex OSAM operations on multiple scales, iterate on technology designs faster, achieve higher operational accuracy, and ultimately reduce mission development costs. A comprehensive, high-fidelity simulation environment will ensure the successful servicing, assembly, and manufacturing of structures that help us study and explore our universe.

isam↗
DOE OSTI2013

The beryllium quandary: will the lower exposure limits spur new developments in sampling and analysis?

At the time this article was written, new rulemakings were under consideration at OSHA and the U.S. Department of Energy (DOE) that would propose changes to occupational exposure limits for beryllium. Given these developments, it’s a good time to review the tools and methods available to IHs for assessing beryllium air and surface contamination in the workplace—what’s new and different, and what’s tried and true. The article discusses limit values and action levels for beryllium, problematic aspects of beryllium air sampling, sample preparation, sample analysis, and data evaluation.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Integral Measurement of the 237 Np($n$, γ) 238 Np Cross Section with Fast Neutrons

Accurate knowledge of the 237 Np($n$; γ) 238 Np cross section at fast neutron energies is important for applied nuclear science. The presently available experimental data has large disagreements in the fast neutron region. A measurement of the 237 Np($n$; γ) 238 Np cross section was performed using a well characterized fast neutron source and the results was compared with previous measurements and current nuclear data evaluations. This will provide an integral measurement that can be used as a benchmark for current evaluations. Multiple samples of 237 Np were irradiated in the Godiva-IV critical assembly. Following the irradiation, the samples placed in a γ-ray counting setup and the γ-rays emitted from the decay of 238 Np were measured over a time period of approximately 7 days. Multiple γ-ray decay branches of 238 Np were observed. The observed activity of 238 Np was used to calculate the amount of 238 Np produced during the irradiation via the 237 Np($n$; γ) 238 Np and an integral cross section of 359(10) mb was measured. The 238 Np half-life has been measured with a result of 50.34(7) hours. An integral measurement of the 237 Np($n$; γ) 238 Np cross section has been measured. This result has been compared to the calculated integral cross section using the ENDF/BVIII.0 and JENDL-4.0 evaluated cross sections and found to be in good agreement with ENDF/BVIII.0 value of 367 mb. The JENDL-4.0 evaluation yields a value of 312 mb, which is significantly lower than the measured cross section.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

November Mega-AI Newsletter

Mega AI, an internal investment at Pacific Northwest National Laboratory, aims to develop next-generation artificial intelligence (AI) capabilities unique to the Department of Energy national lab complex to address research gaps in large-scale multimodal representation learning, multitask inferences, and the need for increased generalizability, rapid adaptivity, and usability of AI technologies. In this newsletter, we highlight recent developments in the research community on next-gen AI technologies focusing on massive-scale model development, deployment and evaluation, data and code availability, model interactions, and new features and capabilities that are relevant to Mega AI’s goals and science and security applications.

Volkova, Svitlana↗
DOE OSTI2015

GRAPhEME: a setup to measure (n, xn γ) reaction cross sections

Most of nuclear reactor developments are using evaluated data base for numerical simulations. However, the considered databases present still large uncertainties and disagreements. To improve their level of precision, new measurements are needed, in particular for (n, xn) reactions, which are of great importance as they modify the neutron spectrum, the neutron population, and produce radioactive species. The IPHC group started an experimental program to measure (n, xn gamma) reaction cross sections using prompt gamma spectroscopy and neutron energy determination by time of flight. Measurements of (n, xn gamma) cross section have been performed for {sup 235,238}U, {sup 232}Th, {sup nat,182,183,184,186}W, {sup nat}Zr. The experimental setup is installed at the neutron beam at GELINA (Geel, Belgium). The setup has recently been upgraded with the addition of a highly segmented 36 pixels planar HPGe detector. Significant efforts have been made to reduce radiation background and electromagnetic perturbations. The setup is equipped with a high rate digital acquisition system. The analysis of the segmented detector data requires a specific procedure to account for cross signals between pixels. An overall attention is paid to the precision of the measurement. The setup characteristic and the analysis procedure will be presented along with the acquisition and analysis challenges. Examples of results and their impact on models will be discussed. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2023

Development of a Geothermal Module in reV: Quantifying the Geothermal Potential while Accounting for the Geospatial Intersection of the Grid Infrastructure and Land Use Characteristics

The Renewable Energy Potential (reV) model is a geospatial platform for estimating technical potential and developing renewable energy supply curves, initially developed for wind and solar technologies. The model evaluates deployment constraints, considering land use, environmental, and cultural factors, and estimates the distance to existing grid features to connect future plants (Maclaurin et al., 2021). A pressing deficiency in the reV model, however, is representation of geothermal electricity generation technologies. To address this gap, we developed a novel geothermal generation module for reV that allows for representation and analysis at the same level of detail as other renewable technologies. This paper describes our process for evaluating data sources for the modeling, and presents five preliminary reV geothermal results. More specifically, we present two sets of resource data that represent upper and lower bounds for geothermal potential. We then present several sensitivity runs using the upper bound resource data; the results are encouraging that levelized cost of electricity (LCOE) can be reduced by optimizing the location and estimated capacity of the spatially diverse geothermal resource while considering the distance to existing grid infrastructure. Our preliminary supply curves and levelized cost of electricity (LCOE) results should be considered with care due to the highly uncertainty in geothermal resource potential data. We present median LCOE values for the conterminous U.S. for five scenarios: four hydrothermal (3.5km depth) and one EGS (4.5km depth). The capital and operating costs for each respective technology are modeled. We also compare results using two different resource data sources.

exclusions↗
DOE OSTI2020

Opportunities to Implement Solutions to Achieve Remedial Action Objectives in Consideration of Stakeholder Interests - 20365

A case study in the implementation of a soils excavation and removal project conducted at a Formerly Utilized Sites Remedial Action Program (FUSRAP) Maywood Superfund Site (FMSS) vicinity property; an active commercial business, in a densely populated area, with significant operational, technical and, logistical constraints that were expected to limit areas that could be remediated. The United States Army Corps of Engineers-led (USACE) team successfully navigated complex overlapping stakeholder interests to achieve a more efficient and complete removal of contaminated soils and debris while minimizing unnecessary excess costs to the Government. This paper centers on FUSRAP activities at the FMSS vicinity property located at 149-151 Maywood Avenue, Maywood, Bergen County, New Jersey. For most of its FUSRAP history, this ∼109,000 square meter (27-acre) property housed a now-demolished ∼26,000 square meter (6.5-acre) warehouse operated by Sears Logistics Services, a unit of the Sears Roebuck Company (Figure 2). Sears ended its property lease and vacated the warehouse in December 2016. Given that long history and for the purposes of this paper, the property will be referred to as the 'Sears property' or simply 'the property.' The Sears property is approximately 109,000 square meters (27-acres) and is currently zoned for commercial use. The property is bound to the north and northwest by 100 West Hunter Avenue (the Stepan Company), to the northeast by 205 Maywood Avenue, to the east by Maywood Avenue, to the south by 23 West Howcroft Road, and to the west by businesses on NJ Route 17 and the NJ Route 17 roadway. Until December 2016, the property housed a warehouse and distribution center operated by Sears Logistical Services. On-site structures were demolished by the property owner in 2017. The warehouse covered the north section of the property along the Stepan Company property line. A railroad spur from the adjacent property now known as the Maywood Interim Storage Site (MISS) ended at the northeast corner of the warehouse. Wetlands were located east of the warehouse; the rest of the property was covered with paved parking lots and grassed areas. During remediation at the property, opportunities frequently arose where the project team was able to coordinate effectively with stakeholders to sequence remediation activities to facilitate removal of otherwise inaccessible soils and identify opportunities for materials reuse when supported by residual radiological and chemical levels. Some specific opportunities include: - remediating individual truck loading dock bays to maintain tenant operations; - working along a busy highway and in a utility corridor containing a 30-inch high pressure gas main; - remediating Lodi Brook and associated wetlands requiring bypass pumping and other diversionary structures to maintain local community stormwater drainage; - protecting during remediation and supporting access to facilitate tenant/owner maintenance of critical fire protection and water supply system service lines buried in contaminated soils and necessary for safe warehouse operations; and - coordinating with stakeholders to ensure non-radiological contaminants of concern for the site (unaffiliated with FUSRAP) were addressed by the responsible party in a manner that maximized benefit to all parties while supporting an efficient overall site remediation program. Once the property was vacant and the warehouse structure and radiologically non-impacted above-grade structures were demolished, the project identified an opportunity to significantly reduce the volume of waste associated with the foundation of the former warehouse, a foundation suspected of being partially constructed in radiologically contaminated soils. The project developed and implemented supplemental radiological verification survey and sampling strategies based on radiological cross-contamination risk potential with process flow-charts and screening-level based decision points; a program that classified saw-cut sections of concrete based on observed residual surface radioactivity conditions using a combination of gamma sensitive sodium-iodide scans and beta sensitive Geiger-Muller direct measurements. The proposed approach was reviewed with stakeholders with feedback, including consideration of applicable State of New Jersey Site Remediation Program criteria and guidance before implementation. Once classified, additional sampling was performed at frequencies driven by screening. The sampling methods, stockpile sampling frequencies, criteria and, approach to data evaluation were developed in consideration of existing site cleanup standards, regional background ranges, State of New Jersey radiological remediation program guidance, and specific stakeholder input With the property remediation and survey efforts nearly completed, it is relevant to examine retrospectively the objectives, assumptions and limitations in the remedial design (i.e., what was planned) versus what was able to be accomplished through effective teaming. Benefits to other environmental remediation site programs include better understanding of how to work effectively with stakeholders to achieve win-win outcomes, and approaches to site remediation, waste minimization and materials reuse that were successful in their overall outcomes. (authors)

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

Validation of nuclear data based on the ASPIS experiments from the SINBAD database - 25428

SINBAD, the Shielding Integral Benchmark Archive and Database, includes the experimental data relative to integral benchmark experiments relevant for radiation shielding applications. The ASPIS experiments, included in the Reactor Shielding section of SINBAD, provide neutron activation foils and spectra measurements performed before/between shielding slabs of Graphite, Sodium, Iron, Steels, Water and combinations of them. Benchmark models for the measurement simulations with the MCNP code are usually provided in SINBAD. Nonetheless, a user-friendly tool is presented, which would be useful for an independent production of MCNP benchmark models. It is based on GPL C++ code called CombLayer. The reports issued for SINBAD on the quality assessment of the ASPIS experiments are also described. The discussion on the quality of the ASPIS experiments for their use in nuclear data evaluations had a positive outcome, except for two experiments out of ten. (authors)

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2015

Implementation and Validation of Reference Sensitivity Profile Calculations in TRIPOLI 4 - 14247

In current neutron transport calculations, particularly on continuous-energy Monte-Carlo codes, the major source of uncertainty is coming from nuclear data. In order to improve nuclear data evaluations, integral experiments are used. Feedback is then precisely obtained by re-estimating cross-section levels and correlations according to their sensitivity. k{sub eff}-sensitivity coefficients are traditionally obtained using deterministic codes since hands-on methods were not yet implemented in continuous energy Monte Carlo codes. In this paper, an Iterated-Fission-Probability-based method newly developed in the continuous energy Monte Carlo code TRIPOLI-4 will be used to calculate sensitivity coefficient breakdown on isotopes and reactions and results will be compared to those of ERANOS deterministic code. Objective is twofold: to show the reliability of the new TRIPOLI-4 method and to identify where and why profiles are slightly different. Sensitivity profiles, forward and adjoint fluxes are thus meticulously compared using a fine 1968-group energy structure. An OECD international benchmark (Uncertainty Analysis for Criticality Safety Assessment - UACSA - Phase III) is taken as working example to enforce validation and to compare to independent results (e.g. MCNP-6). This benchmark is constituted of two bare spheres filled with homogeneous mixture of uranium and polyethylene (respectively 2% and 50% U-235 enrichments) and gives an overview of issues encountered in thermal reactor cores. Several energy-group structures (1968G, 172G, 33G) are also tested in ERANOS to identify multi-group and implicit effects. Lessons learnt are that continuous Monte Carlo methods seem to be mature and compare well with deterministic codes. Only damper the U-238 elastic - and on certain conditions the U-238 capture - sensitivity coefficient for which difference can reach 30% between TRIPOLI-4 and ERANOS. Indeed concerning U-238, implicit effects are emphasized and multi-group theory remains limited by hypothesis; even a 1968-group structure is not refined enough to properly calculate U-238 elastic scattering k{sub eff}-sensitivity. This reference 3D continuous-energy sensitivity capability in TRIPOLI4-IFP will be extensively used in the uncertainty automated tool RIB of the French Criticality-Safety package CRISTAL. (authors)

42 ENGINEERING↗
DOE OSTI2024

Development of a Geothermal Module in reV: Quantifying the Geothermal Potential While Accounting for the Geospatial Intersection of the Grid Infrastructure and Land Use Characteristics: Preprint

The Renewable Energy Potential (reV) model is a geospatial platform for estimating technical potential and developing renewable energy supply curves, initially developed for wind and solar technologies. The model evaluates deployment constraints, considering land use, environmental, and cultural factors, and estimates the distance to existing grid features to connect future plants (Maclaurin et al., 2021). A pressing deficiency in the reV model, however, is representation of geothermal electricity generation technologies. To address this gap, we developed a novel geothermal generation module for reV that allows for representation and analysis at the same level of detail as other renewable technologies. This paper describes our process for evaluating data sources for the modeling, and presents five preliminary reV geothermal results. More specifically, we present two sets of resource data that represent upper and lower bounds for geothermal potential. We then present several sensitivity runs using the upper bound resource data; the results are encouraging that levelized cost of electricity (LCOE) can be reduced by optimizing the location and estimated capacity of the spatially diverse geothermal resource while considering the distance to existing grid infrastructure. Our preliminary supply curves and levelized cost of electricity (LCOE) results should be considered with care due to the highly uncertainty in geothermal resource potential data. We present median LCOE values for the conterminous U.S. for five scenarios: four hydrothermal (3.5km depth) and one EGS (4.5km depth). The capital and operating costs for each respective technology are modeled. We also compare results using two different resource data sources.

exclusions↗
DOE OSTI2014

Nuclear Data Sheets for A=243

We present available information pertaining to the nuclear structure of all nuclei with mass numbers A=243. Various decay and reaction data are evaluated and compared. Adopted data, levels, spin, parity and configuration assignments are given. When there are insufficient data, expected values from systematics of nuclear properties or/and theoretical calculations are quoted. Unexpected or discrepant experimental results are also noted. A summary and compilation of the discovery of various isotopes in this mass region is given in 2013Fr02 ( 243 Np, 243 Pu, 243 Am, 243 Cm, 243 Bk, and 243 Cf), 2011Me01 ( 243 Es), and 2013Th02 ( 243 Fm).

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

Well Stimulation Treatment in California: Evaluation of Disclosure Data, May 2015 – October 2019

In this document, disclosure data from 1,228 well stimulations occurring May 2015 to October 2019 in California are evaluated. This evaluation updates a previous study that was based on 618 well stimulations occurring May 2015 to June 2016 (Stringfellow, W.T., Camarillo, M.K., and Jordan, P. 2017, Status of Well Stimulation in California Since Implementation of SB-4 Regulations, Berkeley National Laboratory, Berkeley, CA). While the goal of the previous study was to provide a summary of information obtained since passage of California Senate Bill No. 4—Oil and Gas, the goal of the current evaluation is to provide a basis for studying chemical indicators that could potentially be used to detect aquifer contamination. We evaluate chemical indicators is a separate document using the data contained herein as well as data from monitoring wells located within oil fields. Compared with the data used by Stringfellow et al. 2017, the current evaluation is based on a more diverse data set. While the previous study contained data for only two oil fields with more than 30 well stimulations, the current data set contains four oil fields with more than 30 well stimulations, making these data more ideal for comparisons using statistical tests. More producers and a new oil field, Buena Vista Nose, are represented in the current data set. Some well stimulation practices remain relatively unchanged since the previous study. Well stimulation is mostly occurring in Kern County with the exception of a single well stimulation in Orange County. Almost all well stimulations are hydraulic fracturing. The current data set contains two acid fracturing treatments and one matrix acidizing treatment. The median number of chemicals added per well stimulation—excluding water and proppant—was previously 21; the number in the expanded data set is 20. Median water added per well stimulation was previously 89,000 gallons and is now 98,000 gallons. While this water use represents a 10% increase, water use for hydraulic fracturing in California is still lower than water use in other oil and gas fields. Chemical formulations appear to have shifted since the previous study. This shift may be related to a change in the predominant service company. We identified 26 chemicals for which the frequency of use has changed by more than 30%. The total number of chemicals used has also expanded. Previously, 178 unique chemicals were identified as being added to well stimulation fluids. The total number of unique chemicals is now 205. Analytical data available for base and recovered fluids has expanded. The number of base fluid samples has increased from 12 to 35 and the number of recovered fluid samples has increased from 1,078 to 2,166. The expanded data set is more ideal for an evaluation of indicator chemicals and comparisons across different formations. The analytical data for recovered fluid samples indicates that many ions, radioactive constituents, and organics are consistently observed, making these chemicals ideal for consideration as potential indicators of aquifer contamination.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1972

Evaluation of thermal network correction program using test temperature data

An evaluation process to determine the accuracy of a computer program for thermal network correction is discussed. The evaluation is required since factors such as inaccuracies of temperatures, insufficient number of temperature points over a specified time period, lack of one-to-one correlation between temperature sensor and nodal locations, and incomplete temperature measurements are not present in the computer-generated information. The mathematical models used in the evaluation are those that describe a physical system composed of both a conventional and a heat pipe platform. A description of the models used, the results of the evaluation of the thermal network correction, and input instructions for the thermal network correction program are presented.

Ishimoto, T.↗
NASA NTRS1975

Evaluation of a data dictionary system

The usefulness was investigated of a data dictionary/directory system for achieving optimum benefits from existing and planned investments in computer data files in the Data Systems Development Branch and the Institutional Data Systems Division. Potential applications of the data catalogue system are discussed along with an evaluation of the system. Other topics discussed include data description, data structure, programming aids, programming languages, program networks, and test data.

Driggers, W. G.↗
NASA NTRS1992

Cockpit data link displays - An evaluation of textual formats

Data link technologies are being investigated for air/ground information transfer for commercial aircraft operation. This study was designed to measure which of four alpha-numeric display formats for display of data link information would lead to the quickest and most accurate memory retrieval in a part-task simulation environment. Pilots viewed a clearance for 10-15 seconds and were subsequently queried about the content of that clearance. Speed and accuracy of responses were measured across three retention tasks. The three retention tasks included free recall of a particular clearance. recognition of a previous clearance, and the comparison of element values between a previously displayed and current clearance. Each format was tested with and without a distraction task. Subjective ratings of each format were also collected. The analyses revealed no significant differences for reaction time or accuracy among the four formats. Explanations for these results as well as alternative methodologies are discussed.

Mcgann, Alison↗
DOE OSTI2013

Nuclear Data Sheets for A = 215

The evaluated spectroscopic data are presented for 12 known nuclides of mass 215 (Hg, Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa). For {sup 215}Hg, {sup 215}Tl, {sup 215}Pb, and {sup 215}Pa nuclei, no excited states are known. The decay characteristics of {sup 215}Hg and {sup 215}Tl are unknown. The decay scheme of {sup 215}Pb is considered as incomplete. Ordering of γ cascades in the decay of 36.9–s isomer of {sup 215}Bi and for high–spin states above 2251 keV in {sup 215}Fr are not established. High–spin excitations, including several isomeric states, are well known in {sup 215}Bi, {sup 215}Po, {sup 215}Rn, {sup 215}Fr, {sup 215}Ra, and {sup 215}Ac. No particle–transfer reaction data are available for any of the A=215 nuclei. The rms charge radii for {sup 215}Pb, {sup 215}Bi, {sup 215}Po, {sup 215}Rn, {sup 215}Fr and {sup 215}Ra have been evaluated by Daniel Abriola, from extrapolation or interpolation of available evaluated data in 2013An02 for radii of respective Z chains using formula 9 in 2004An14. This evaluation was carried out as part of ENSDD–workshop at VECC, Kolkata for Nuclear Structure and Decay Data, organized and hosted by VECC and Board of Research in Nuclear Sciences (BRNS) in Kolkata, India, November 26–29, 2012. This work supersedes the previous A = 215 evaluation (2001Br31) published by E. Browne which covered literature prior to May 2001.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗