Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Gap Assessment”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Cited Reference Analysis in a National Laboratory to Assess Journal Usage

Librarians at a large, federally funded, multidisciplinary research organization sought to assess the value provided by the library’s collections. One method for capturing this value includes determining how well their library’s collections meet researcher needs, as expressed by the materials those researchers choose to cite in the production of new scholarly communications. A cited reference analysis was performed on the publications originating from the institution to provide the necessary data for the assessment, as well as to aid in the creation of a core list of journals which will inform future collection development efforts. Overall, this paper fills a gap in the library and information science literature by addressing the citation behaviors of researchers at a large multidisciplinary government research facility, a setting that has not been examined previously.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2021

Control of CuPt Ordering in GaInP Grown by Hydride Vapor Phase Epitaxy

We investigate the degree of ordering present in GaInP layers grown by dynamic hydride vapor phase epitaxy (D-HVPE) as a function of various growth conditions. We assess order parameter from both transmission electron and x-ray diffraction and compare these trends to the order parameter estimated by the photoluminescence-determined band gap in the GaInP layers. The degree of ordering increases with deposition temperature and the ratio of gas-phase group V to group III precursors in the reactor. We also investigate the effect of growth rate, demonstrating the capability of HVPE to suppress order through rapid growth rates. Such ordering dependences are consistent with mechanisms established for ordering observed in GaInP grown by organometallic vapor phase epitaxy (OMVPE), but with weaker ordering than GaInP grown by that method.

growth↗
DOE OSTI2023

Legacy Site 377 (Former Building 377) Soil Sampling and Analysis Plan Addendum 1 (April 2023)

The purpose of this addendum is to address data gaps identified in the Legacy Site 377 (Former Building 377) Soil Sampling and Analysis Plan (SAP) (LLNL-AM-826971) (LLNL 2021a) and the Phase II Site Assessment Report for Legacy Slab 377 (LLNL-TM-828194) (LLNL 2021b). This addendum will be used in conjunction with the 2021 SAP. All policies and procedures set forth in the SAP that are not modified in this addendum will remain in effect for the duration of the project, where applicable.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1978

Effects of arcing due to spacecraft charging on spacecraft survival

A quantitative assessment of the hazard associated with spacecraft charging and arcing on spacecraft systems is presented. A literature survey on arc discharge thresholds and characteristics was done and gaps in the data and requirements for additional experiments were identified. Calculations of coupling of arc discharges into typical spacecraft systems were made and the susceptibility of typical spacecraft to disruption by arc discharges was investigated. Design guidelines and recommended practices to reduce or eliminate the threat of malfunction and failures due to spacecraft charging/arcing were summarized.

Rosen, A.↗
NASA NTRS2012

Vegetation Phenology Metrics Derived from Temporally Smoothed and Gap-filled MODIS Data

Smoothed and gap-filled VI provides a good base for estimating vegetation phenology metrics. The TIMESAT software was improved by incorporating the ancillary information from MODIS products. A simple assessment of the association between retrieved greenup dates and ground observations indicates satisfactory result from improved TIMESAT software. One application example shows that mapping Nectar Flow Phenology is tractable on a continental scale using hive weight and satellite vegetation data. The phenology data product is supporting more researches in ecology, climate change fields.

Tan, Bin↗
NASA NTRSDate not supplied

NASA Advanced Space Suit Pressure Garment System Status and Development Priorities 2022

This paper discusses the current focus of NASA’s Advanced Space Suit Pressure Garment Technology Development team’s efforts, the status of that work, and a summary of longer-term technology development priorities and activities. For the past two years, the team has focused on the development and detailed design of the Extra-Vehicular Mobility Unit (xEMU) to support two parallel missions: A 2023 deadline for delivery of the xEMU International Space Station (ISS) Demonstration configuration, and a planetary walking suit configuration to support landing on the Moon in 2024. The baselined design of the xEMU will be reviewed. The results of Design Verification Testing (DVT) will be presented and its ability to provide confidence in the hardware’s ability to meet flight requirements will be discussed. To the extent possible, an impact assessment of the Exploration Extra-Vehicular Activity Services (xEVAS) Contract will be provided. Finally, a brief review of longer-term pressure garment challenges and technology gaps will be presented to provide an understanding of the advanced pressure garment team’s technology investment priorities and needs for future exploration missions.

NASA↗
NASA NTRSDate not supplied

Human Systems Integration (HSI) Framework and Training - Shifting the View of HSI for Better Implementation

The Implementation of Human Systems Integration (HSI) presents challenges within the acquisition community for two reasons. The first is that misconceptions of HSI still exist, with many Program Managers (PMs) and leadership uncertain of the value or where to begin. The second is due to an unbalanced approach to HSI in its own framework. These implementation challenges lead to barriers in the early prevention of mishaps. Understanding HSI practices and how they should be implemented in the Acquisition Product Life Cycle (PLC) has been a challenge across the government, leaving the value of HSI unknown and misunderstood with Program Managers. In the case for many acquisition programs, HSI is not implemented in early design, losing the perspective on human capabilities and limitations, creating impacts on human-centered design. Expectations in human performance are not clearly set and operations are baselined with no margin for changes in technology and processes that will affect system performance. The HSI framework addresses total system performance holistically using collaboration as the primary tool. The goal is to create a system with efficiencies while minimizing risk to the operators, maintainers, and support personnel, as well as any collateral personnel and systems. To accomplish this, HSI should be implemented as part of preemptive measures to minimize potential human error and mishaps during the operation phase. Investigative and assessment tools exist that consider events, issues, and other outside influences of a system that may not fall under the current construct of the HSI domains, leaving gaps in early HSI implementation and affecting the prevention of human errors and mishaps. This presentation will outline what NASA HSI is doing to support Early HSI implementation and Operational Performance shifts that affect human performance.

Anthony T Thomas↗
NASA NTRS2023

Flexible Data Fusion for Air Quality Estimation and Forecasting in Google Earth Engine to support Global Health Management Needs

The assessment and forecasting of air quality around the world at high spatial and temporal resolution can be enhanced by integrating data from multiple sources including models, satellites, regulatory monitors, and low-cost sensors. Such integration is subject to numerous technical challenges, however, including heterogeneous data resolution and formatting, different levels of data availability and reliability, and computational and capacity challenges to developing data fusion tools and platforms. This presentation will provide an overview of a NASA-funded effort to develop a data fusion system within the Google Earth Engine platform which integrates these air quality data sources to produce comprehensive assessments and forecasts of key air pollutants at sub-daily and sub-city scales. The system is being developed in collaboration with city- and regional-level air quality managers, and will provide them with information to the assess and anticipate the health impacts of poor air quality, track local changes in air quality due to ongoing transportation and land use changes, and identify potential gaps in their current air quality monitoring strategies. The presentation will report advances achieved through the project, including bringing local air quality monitoring data into Google Earth Engine, quantifying uncertainties in air quality estimates and forecasts, and tailored communications tools providing integration into end-user processes to meet their needs.

Carl Malings↗
NASA NTRSDate not supplied

Flexible Data Fusion for Air Quality Estimation and Forecasting in Google Earth Engine to support Global Health Management Needs

The assessment and forecasting of air quality around the world at high spatial and temporal resolution can be enhanced by integrating data from multiple sources including models, satellites, regulatory monitors, and low-cost sensors. Such integration is subject to numerous technical challenges, however, including heterogeneous data resolution and formatting, different levels of data availability and reliability, and computational and capacity challenges to developing data fusion tools and platforms. This presentation will provide an overview of a NASA-funded effort to develop a data fusion system within the Google Earth Engine platform which integrates these air quality data sources to produce comprehensive assessments and forecasts of key air pollutants at sub-daily and sub-city scales. The system is being developed in collaboration with city- and regional-level air quality managers and will provide them with information to the assess and anticipate the health impacts of poor air quality, track local changes in air quality due to ongoing transportation and land use changes, and identify potential gaps in their current air quality monitoring strategies. The presentation will report advances achieved through the project, including bringing local air quality monitoring data into Google Earth Engine, quantifying uncertainties in air quality estimates and forecasts, and tailored communications tools providing integration into end-user processes to meet their needs.

Nathan R. Pavlovic↗
NASA NTRS2024

Risk of Bone Fracture due to Spaceflight-induced Changes to Bone

The Human Research Program (HRP) is taking a biomechanical approach to assessing subsequent fracture risk in active astronauts as a consequence of spaceflight exposure. Triennial testing of active and retired astronauts continues as Space Medicine monitors for a premature diagnosis of primary osteoporosis, which is associated with age-related bone loss and skeletal fragility. This updated 2023 Fracture Evidence Report has expanded the description of skeletal changes to capture the full effects of spaceflight on bone: • Recent analysis of fractures from health records of the full astronaut cohort, suggests an increased incidence rate of hip and spine fractures in astronauts following longer spaceflight duration flights compared to incident rates found in shorter duration flights. • Routine preflight-to-postflight surveillance by DXA (dual-energy x-ray absorptiometry) does not provide the full detection of loss and recovery in the long-duration (LD) astronaut nor the full recovery of hip trabecular bone. • The inclusion of hip quantitative computed tomography (QCT) in flight studies delineates effects of spaceflight, of countermeasures, and of post-flight recovery on cortical and trabecular bone parameters—some of which are verified predictors of hip fracture in the aged. • QCT detects and compares the distinct countermeasure effects of the pharmaceutical alendronate and of resistive exercise (on the Advanced Resistive Exercise Device, ARED) in specific cortical and trabecular bone sub-regions during spaceflight. • A published comparison of QCT-determined loss rates of hip trabecular bone in LD astronauts compared to terrestrial cohorts suggest that accelerated loss rates in trabecular volumetric BMD (vBMD) during spaceflight might be analogous to skeletal effects of accelerated loss rates in females due to menopause, potentially leading to disruptions in trabecular microarchitecture. • A dataset of finite element (FE) estimates of hip bone strength in aging terrestrial cohorts (spanning astronaut age-range) provides comparative context for changes in the FE of hip bone strength in LD astronauts, including comparison (force unit of newton) to percentiles (50th, 75th, and 100th) of sex-matched aged humans with hip fractures. • Risk of fracture, due to the mechanical overloading of bones, is being updated with IMPACT, the next-generation tool suite for probabilistic risk assessment (PRA) for exploration missions being created by the Exploration and Medical Capability Element (ExMC) at NASA. IMPACT is currently in development and will not be included in this 2024 update. The risk for fracture necessitates understanding the relationship between applied loads to bone and the biomechanical competence of bone. The Risk for Early Onset Osteoporosis focuses on the weakened condition of bone (including development of new technologies, measurements of novel skeletal attributes, translation of multiple measures to an index of bone fragility, and interpretations of data used to reflect a weakened bone), while the Risk for Fracture assesses factors that influence the probability an astronaut would encounter applied loads exceeding the biomechanical competence of bones, resulting in fracture. This Evidence Report combines the research gaps and tasks associated with both risks.

Fracture↗
DOE OSTI2020

F2 extraction from Inclusive Cross Section Data at Large Bjorken x

While we have made significant progress in probing nuclear structure at low Bjorken x and high Q 2 , we still have gaps in our knowledge regarding the high Bjorken x and intermediate Q 2 kinematic region. This is not an accident, but instead due to the diffculty in assessing the non-perturbative region of nuclear physics. For this reason, the E12-10-002 experiment measured the H(e,e') and D(e,e') inclusive cross section in the resonance region. This will allow us to study both perturbative and non-perturbative physics in a kinematic region that lacks precision measurements. Measurements were made up to a Bjorken x of 0.99 and Q 2 up to 17 GeV 2 . These measurements are made using the independent HMS and SHMS spectrometers at the upgraded beam energy of 11 GeV in Hall C at Jefferson Lab. Further, we extract F 2 structure functions from the measured data and study the effect of their inclusion in a global Parton Distribution Function analysis.

Araiza Gonzalez, Fernando↗
NASA NTRS2015

Technology Candidates for Air-to-Air and Air-to-Ground Data Exchange

Technology Candidates for Air-to-Air and Air-to-Ground Data Exchange is a two-year research effort to visualize the U. S. aviation industry at a point 50 years in the future, and to define potential communication solutions to meet those future data exchange needs. The research team, led by XCELAR, was tasked with identifying future National Airspace System (NAS) scenarios, determining requirements and functions (including gaps), investigating technical and business issues for air, ground, & air-to-ground interactions, and reporting on the results. The project was conducted under technical direction from NASA and in collaboration with XCELAR's partner, National Institute of Aerospace, and NASA technical representatives. Parallel efforts were initiated to define the information exchange functional needs of the future NAS, and specific communication link technologies to potentially serve those needs. Those efforts converged with the mapping of each identified future NAS function to potential enabling communication solutions; those solutions were then compared with, and ranked relative to, each other on a technical basis in a structured analysis process. The technical solutions emerging from that process were then assessed from a business case perspective to determine their viability from a real-world adoption and deployment standpoint. The results of that analysis produced a proposed set of future solutions and most promising candidate technologies. Gap analyses were conducted at two points in the process, the first examining technical factors, and the second as part of the business case analysis. In each case, no gaps or unmet needs were identified in applying the solutions evaluated to the requirements identified. The future communication solutions identified in the research comprise both specific link technologies and two enabling technologies that apply to most or all specific links. As a result, the research resulted in a new analysis approach, viewing the underlying architecture of ground-air and air-air communications as a whole, rather than as simple "link to function" paired solutions. For the business case analysis, a number of "reference architectures" were developed for both the future technologies and the current systems, based on three typical configurations of current aircraft. Current and future costs were assigned, and various comparisons made between the current and future architectures. In general, it was assumed that if a future architecture offers lower cost than the current typical architecture, while delivering equivalent or better performance, it is likely that the future solution will gain industry acceptance. Conversely, future architectures presenting higher costs than their current counterparts must present a compelling benefit case in other areas or risk a lack of industry acceptance. The business case analysis consistently indicated lower costs for the proposed future architectures, and in most cases, significantly so. The proposed future solutions were found to offer significantly greater functionality, flexibility, and growth potential over time, at lower cost, than current systems. This was true for overall, fleet-wide equipage for domestic and oceanic air carriers, as well as for single, General Aviation (GA) aircraft. The overall research results indicate that all identified requirements can be met by the proposed solutions with significant capacity for future growth. Results also illustrate that the majority of the future communication needs can be met using currently allocated aviation RF spectrum, if used in more effective ways than it is today. A combination of such optimized aviation-specific links and commercial communication systems meets all identified needs for the 50-year future and beyond, with the caveat that a new, overall function will be needed to manage all information exchange, individual links, security, cost, and other factors. This function was labeled "Delivery Manager" (DM) within this research. DM employs a distributed client/server architecture, for both airborne and ground communications architectures. Final research results included identifying the most promising candidate technologies for the future system, conclusions and recommendations, and identifying areas where further research should be considered.

Communications↗
DOE OSTI2025

Secure Route: Roadway Risk Mapping for Transportation Planners

The secure transport of sensitive materials across U.S. road networks pose unique challenges for local, state, and federal agencies. Threats range from random events (e.g., accidents, medical emergencies, mechanical failures) to opportunistic or organized tactical assaults. Although the probability of such attacks is very low, the consequences of material loss to foreign states or terrorists can be catastrophic, qualifying these scenarios as “grey swan” events—low-probability, high-impact occurrences that are predictable but difficult to quantify. Traditional risk assessments struggle in these contexts, necessitating a shift toward subjective risk perception to inform planning. Risk perception in transport planning is shaped by various factors, including knowledge of adversarial capabilities, vehicle defenses, manifest details, and geographic features along the route. Geographic features such as bridges, tunnels, roadside elevation, and gaps in cellular coverage introduce vulnerabilities, while mitigative features include safe havens, police stations, and medical services. Temporal variables such as congestion, accidents, and weather further complicate route planning. Despite their importance, existing routing tools like Google Maps and commercial software do not explicitly account for geographic risk features, requiring planners to rely on personal familiarity with routes—a time-intensive, non-scalable approach. This work addresses these gaps by: (1) developing datasets that catalog geographic risk features along U.S. roadways, (2) eliciting risk perceptions from experienced transportation security experts, and (3) linking these perceptions to roadway conditions and geographic data. We implement these capabilities within Secure Route a novel mapping tool for classifying route segment risks associated with roadway conditions. This system provides transportation planners with an intuitive interface to assess and contextualize risk along potential routes, improving decision-making for secure transport. We present current progress in this effort and identify next steps.

Stewart, Robert [ORNL] (ORCID:0000000281867559)↗
NASA NTRS2012

ExMC Technology Watch

The Technology Watch (Tech Watch) project is a NASA endeavor conducted under the Human Research Programs (HRP) Exploration Medical Capability (ExMC) element, and focusing on ExMC technology gaps. The project involves several NASA centers, including the Johnson Space Center (JSC), Glenn Research Center (GRC), Ames Research Center (ARC), and the Langley Research Center (LaRC). The objective of Tech Watch is to identify emerging, high-impact technologies that augment current NASA HRP technology development efforts. Identifying such technologies accelerates the development of medical care and research capabilities for the mitigation of potential health issues encountered during human space exploration missions. The aim of this process is to leverage technologies developed by academia, industry and other government agencies and to identify the effective utilization of NASA resources to maximize the HRP return on investment. The establishment of collaborations with these entities is beneficial to technology development, assessment and/or insertion and further NASAs goal to provide a safe and healthy environment for human exploration. In 2011, the major focus areas for Tech Watch included information dissemination, education outreach and public accessibility to technology gaps and gap reports. The dissemination of information was accomplished through site visits to research laboratories and/or companies, and participation at select conferences where Tech Watch objectives and technology gaps were presented. Presentation of such material provided researchers with insights on NASA ExMC needs for space exploration and an opportunity to discuss potential areas of common interest. The second focus area, education outreach, was accomplished via two mechanisms. First, several senior student projects, each related to an ExMC technology gap, were sponsored by the various NASA centers. These projects presented ExMC related technology problems firsthand to collegiate laboratories. Second, a RASC-AL (Revolutionary Aerospace Systems Concepts Academic Linkage) topic for FY12 was developed for medical systems and astronaut health under the Human-Focused Mars Mission Systems and Technologies theme. Announcement of the competition was made to the public in August 2011. Finally, critical Tech Watch information was prepared for public release in the form of gap reports. Complementing the ExMC technology gaps in the public domain, gap reports were generated, reviewed and revised through a series of technical, medical and subject matter expert reviews before approval for public release. An important vehicle for the public release of such documents was development of the ExMC wiki website, which will continue to be populated with gap reports and relevant documents throughout the upcoming year.

Krihak, M.↗
NASA NTRS2013

ExMC Technology Watch

The Technology Watch (Tech Watch) project is a NASA project that is operated under the Human Research Programs (HRP) Exploration Medical Capability (ExMC) element, and focuses on ExMC technology gaps. The project coordinates the efforts of several NASA centers, including the Johnson Space Center (JSC), Glenn Research Center (GRC), Ames Research Center (ARC), and the Langley Research Center (LaRC). The objective of Tech Watch is to identify emerging, high-impact technologies that augment current NASA HRP technology development efforts. Identifying such technologies accelerates the development of medical care and research capabilities for the mitigation of potential health issues encountered during human space exploration missions. The aim of this process is to leverage technologies developed by academia, industry and other government agencies and to identify the effective utilization of NASA resources to maximize the HRP return on investment. The establishment of collaborations with these entities is beneficial to technology development, assessment and/or insertion and further NASAs goal to provide a safe and healthy environment for human exploration. In 2012, the Tech Watch project expanded the scope of activities to cultivate student projects targeted at specific ExMC gaps, generate gap reports for a majority of the ExMC gaps and maturate a gap report review process to optimize the technical and managerial aspects of ExMC gap status. Through numerous site visits and discussions with academia faculty, several student projects were initiated and/or completed this past year. A key element to these student projects was the ability of the project to align with a specific ExMC technology or knowledge gap. These projects were mentored and reviewed by Tech Watch leads at the various NASA centers. Another result of the past years efforts was the population of the ExMC wiki website that now contains more the three quarters of the ExMC gap reports. The remaining gap reports will be completed in FY13. Finally, the gap report review process for all ExMC gaps was initiated. This review process was instrumental in ensuring that each gap report was thoroughly reviewed for accuracy and relevant content prior to its public release. In the upcoming year, the gap report review process will be refined such that in addition to the gap report update, programmatic information related to gap closure will also be emphasized.

Krihak, M.↗
NASA NTRS2024

Impact of Spaceflight on Earth’s Atmosphere: Climate, Ozone, and the Upper Atmosphere

In order to eliminate potential risk from the lack of scientific understanding and resolve the current inability to assess how a rapidly growing space industry will affect Earth’s atmosphere, a well-defined research effort is recommended. As demonstrated in the white paper “Impacts of Spaceflight on the Global Atmosphere: Current Understanding, Knowledge Gaps, NASA’s Role, and Roadmap", we must improve our ability to model and observe rocket engine combustion, far field rocket plume evolution, impacts on the upper atmosphere, global launch impacts, reentry gas and aerosol production, far field reentry plume evolution, and global reentry impacts. The highly successful Atmospheric Chemistry of Combustion Emissions Near the Tropopause (ACCENT) program serves as a model for the proposed effort. ACCENT was a multiagency research program that included observation and modeling of rocket plumes and played a critical role to remove the threat of regulatory action against the Space Shuttle’s solid rocket motors. A similar effort today would be a combination of remote, in situ, and laboratory measurements that feed into model development and assessment of future launch and reentry emissions.

Ozone Layer↗
DOE OSTI2023

Thermohydraulic Design Analysis of the Target Assembly in the Material Plasma Exposure Experiment Facility

The Material Plasma Exposure eXperiment (MPEX) project seeks to design a steady-state linear plasma facility at Oak Ridge National Laboratory that will be used to study plasma-material interactions (PMIs) at fusion prototypic levels, supporting the evaluation and development of materials for the next generation of fusion devices. This study is focused on PMI exposure of small-size neutron-irradiated specimens, which are clamped onto an actively cooled component. A thermohydraulic evaluation of a new MPEX target assembly design to assess the appropriate operation during MPEX operation is presented. To further guide the design and assess the structural integrity of the components under expected loads, preliminary thermomechanical stress analyses were also conducted. To ensure good thermal contact between the components, thermal interface materials, such as silver flexible graphite, were used in the assembly. It was found that the maximum target temperatures of 1572, 1463, and 1315 K were obtained for Grafoil thicknesses of 0.61, 0.38, and 0.25 mm, respectively. The distribution of the axial deformation at high heat fluxes showed that there are no gaps between components, indicating good contact at material interfaces. Moreover, the contact pressure between the target and other components indicated that very good contact was established at these interfaces. Furthermore, the stress-strain conditions for the target will be further used to assess the appropriate operation during MPEX experiments and gain insight into materials science phenomena during PMI experiments.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2022

Development of Conceptual Lead Cartridge Design to Perform Irradiation Experiments in VTR

This paper seeks to introduce the latest design of the Extended Length Test Assembly–Cartridge Lead (ELTA-CL) with associated thermal-hydraulic (TH) assessment and related experiment activities to support the critical component development performed by the ELTA-CL team (Los Alamos National Laboratory, Westinghouse Electric Company, and the University of New Mexico). The goal of the ELTA-CL program is to develop and validate an experimental capability to perform irradiation experiments in the Versatile Test Reactor (VTR) addressing Lead Fast Reactor (LFR) technology gaps, in support of the commercial development of advanced lead-cooled fast reactor concepts. Through a design maturation process and parametric study, a conceptual design is proposed to meet the requirements for material and corrosion testing. Thermal-hydraulic characteristics for the conceptual design at desired operating conditions are assessed with systems-level (one-dimensional) and computational fluid dynamics (three-dimensional) simulations. Along with the conceptual design work, experimental activities for the development of critical components such as the pump and flowmeter are undertaken. From both the modeling study and the experimental results, the design requirements of the Phase 1 ELTA-CL (e.g., 500°C and 2 m/s) are achievable with the current conceptual design. Additional design improvements and safety assessments at both steady-state and transient conditions for the final ELTA-CL design will be pursued.

42 ENGINEERING↗