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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS2009

Occupant Protection during Orion Crew Exploration Vehicle Landings

The constellation program is evaluating current vehicle design capabilities for nominal water landings and contingency land landings of the Orion Crew Exploration vehicle. The Orion Landing Strategy tiger team was formed to lead the technical effort for which associated activities include the current vehicle design, susceptibility to roll control and tip over, reviewing methods for assessing occupant injury during ascent / aborts /landings, developing an alternate seat/attenuation design solution which improves occupant protection and operability, and testing the seat/attenuation system designs to ensure valid results. The EVA physiology, systems and Performance (EPSP) project is leading the effort under the authority of the Tiger Team Steering committee to develop, verify, validate and accredit biodynamics models using a variety of crash and injury databases including NASCAR, Indy Car and military aircraft. The validated biodynamics models will be used by the Constellation program to evaluate a variety of vehicle, seat and restraint designs in the context of multiple nominal and off-nominal landing scenarios. The models will be used in conjunction with Acceptable Injury Risk definitions to provide new occupant protection requirements for the Constellation Program.

Gernhardt, Michael L.↗
NASA NTRS2015

NASA Astronaut Occupational Surveillance Program and Lifetime Surveillance of Astronaut Health, LSAH, Astronaut Exposures and Risk in the Terrestrial and Spaceflight Environment

United States Astronauts have a very unique occupational exposure profile. In order to understand these risks and properly address them, the National Aeronautics and Atmospheric Administration, NASA, originally created the Longitudinal Study of Astronaut Health, LSAH. The first LSAH was designed to address a variety of needs regarding astronaut health and included a 3 to 1 terrestrial control population in order to compare United States "earth normal" disease and aging to that of a microgravity exposed astronaut. Over the years that program has been modified, now termed Lifetime Surveillance of Astronaut Health, still LSAH. Astronaut spaceflight exposures have also changed, with the move from short duration shuttle flights to long duration stays on international space station and considerable terrestrial training activities. This new LSAH incorporates more of an occupational health and medicine model to the study of occupationally exposed astronauts. The presentation outlines the baseline exposures and monitoring of the astronaut population to exposures, both terrestrial, and in space.

Keprta, Sean R.↗
NASA NTRS2016

Evaluation of Mid-Size Male Hybrid III Models for use in Spaceflight Occupant Protection Analysis

In an effort to improve occupant safety during dynamic phases of spaceflight, the National Aeronautics and Space Administration (NASA) has worked to develop occupant protection standards for future crewed spacecraft. One key aspect of these standards is the identification of injury mechanisms through anthropometric test devices (ATDs). Within this analysis, both physical and computational ATD evaluations are required to reasonably encompass the vast range of loading conditions any spaceflight crew may encounter. In this study the accuracy of publically available mid-size male HIII ATD finite element (FE) models are evaluated within applicable loading conditions against extensive sled testing performed on their physical counterparts. Methods: A series of sled tests were performed at the Wright Patterson Air force Base (WPAFB) employing variations of magnitude, duration, and impact direction to encompass the dynamic loading range for expected spaceflight. FE simulations were developed to the specifications of the test setup and driven using measured acceleration profiles. Both fast and detailed FE models of the mid-size male HIII were ran to quantify differences in their accuracy and thus assess the applicability of each within this field. Results: Preliminary results identify the dependence of model accuracy on loading direction, magnitude, and rate. Additionally the accuracy of individual response metrics are shown to vary across each model within evaluated test conditions. Causes for model inaccuracy are identified based on the observed relationships. Discussion: Computational modeling provides an essential component to ATD injury metric evaluation used to ensure the safety of future spaceflight occupants. The assessment of current ATD models lays the groundwork for how these models can be used appropriately in the future. Identification of limitations and possible paths for improvement aid in the development of these effective analysis tools.

Putnam, Jacob B.↗
NASA NTRS2016

Crew Exploration Vehicle (CEV) (Orion) Occupant Protection: Appendices - Part 1

Dr. Nancy J. Currie, of the NASA Engineering and Safety Center (NESC), Chief Engineer at Johnson Space Center (JSC), requested an assessment of the Crew Exploration Vehicle (CEV) occupant protection as a result of issues identified by the Constellation Program and Orion Project. The NESC, in collaboration with the Human Research Program (HRP), investigated new methods associated with occupant protection for the Crew Exploration Vehicle (CEV), known as Orion. The primary objective of this assessment was to investigate new methods associated with occupant protection for the CEV, known as Orion, that would ensure the design provided minimal risk to the crew during nominal and contingency landings in an acceptable set of environmental and spacecraft failure conditions. This documents contains the appendices to the NESC assessment report. NASA/TM-2013-217380, Application of the Brinkley Dynamic Response Criterion to Spacecraft Transient Dynamic Events supersedes this document.

Currie-Gregg, Nancy J.↗
NASA NTRS2016

Crew Exploration Vehicle (CEV) (Orion) Occupant Protection

Dr. Nancy J. Currie, of the NASA Engineering and Safety Center (NESC), Chief Engineer at Johnson Space Center (JSC), requested an assessment of the Crew Exploration Vehicle (CEV) occupant protection as a result of issues identified by the Constellation Program and Orion Project. The NESC, in collaboration with the Human Research Program (HRP), investigated new methods associated with occupant protection for the Crew Exploration Vehicle (CEV), known as Orion. The primary objective of this assessment was to investigate new methods associated with occupant protection for the CEV, known as Orion, that would ensure the design provided minimal risk to the crew during nominal and contingency landings in an acceptable set of environmental and spacecraft failure conditions. This documents contains the outcome of the NESC assessment. NASA/TM-2013-217380, "Application of the Brinkley Dynamic Response Criterion to Spacecraft Transient Dynamic Events." supercedes this document.

Currie-Gregg, Nancy J.↗
NASA NTRS2016

Evaluation of Mid-Size Male Hybrid III Models for use in Spaceflight Occupant Protection Analysis

Introduction: In an effort to improve occupant safety during dynamic phases of spaceflight, the National Aeronautics and Space Administration (NASA) has worked to develop occupant protection standards for future crewed spacecraft. One key aspect of these standards is the identification of injury mechanisms through anthropometric test devices (ATDs). Within this analysis, both physical and computational ATD evaluations are required to reasonably encompass the vast range of loading conditions any spaceflight crew may encounter. In this study the accuracy of publically available mid-size male HIII ATD finite element (FE) models are evaluated within applicable loading conditions against extensive sled testing performed on their physical counterparts. Methods: A series of sled tests were performed at the Wright Patterson Air force Base (WPAFB) employing variations of magnitude, duration, and impact direction to encompass the dynamic loading range for expected spaceflight. FE simulations were developed to the specifications of the test setup and driven using measured acceleration profiles. Both fast and detailed FE models of the mid-size male HIII were ran to quantify differences in their accuracy and thus assess the applicability of each within this field. Results: Preliminary results identify the dependence of model accuracy on loading direction, magnitude, and rate. Additionally the accuracy of individual response metrics are shown to vary across each model within evaluated test conditions. Causes for model inaccuracy are identified based on the observed relationships. Discussion: Computational modeling provides an essential component to ATD injury metric evaluation used to ensure the safety of future spaceflight occupants. The assessment of current ATD models lays the groundwork for how these models can be used appropriately in the future. Identification of limitations and possible paths for improvement aid in the development of these effective analysis tools.

Putnam, J.↗
NASA NTRS2018

Soyuz Occupant Risk

Spaceflight has unique challenges for Occupant Protection. Current NASA Occupant Protection Requirements are based on military and automotive biodynamics research: Brinkley Dynamic Response Criteria; Hybrid III Anthropomorphic Test Device (ATD). Soyuz offers unique insight into the role of spaceflight deconditioning on impact tolerance. Project Objectives: 1. Develop a landing injury database; 2. Obtain seat acceleration data from TMA (Soyuz-TMA: Transport Modified Anthropometric) landings; 3. Re-create Soyuz landings using models; 4. Update NASA occupant protection standards as needed.

Newby, Nate↗
DOE OSTI2020

Nationwide Energy Saving Potential Evaluation for Office Buildings with Occupant-Based Building Controls

The heating ventilation and air-conditioning (HVAC) system is a major contributor to building energy consumption. This paper aims to quantify the nationwide energy savings potential of implementing the occupancy-based control (OBC) for the HVAC system in typical medium-sized office buildings using a whole building simulation program (i.e., EnergyPlus). First, the medium-sized office from the DOE Commercial Prototype Building Models was modified to have detailed layout and space functions. Then, a statistic-algorithm-based tool was used to generate the dynamic occupancy schedules for various rooms. Next, both a baseline case and two OBC cases were created for the comparison based on the updated ASHRAE Standard 90.1 and ASHRAE Guideline 36. The HVAC operation in the baseline case follows a static occupancy schedule and fixed setpoint schedules for both room air temperatures and minimal system outside air flowrates, while the proposed OBC cases use the room temperature reset, system minimum outdoor airflow reset, and zone minimal supply airflow rate reset. These cases were extended to five climate zones in the United States to further quantify the energy savings potential associated with the OBC on a nationwide scale. The preliminary result of this case study shows that there could be significant energy savings potential from the proposed OBC strategies in medium-sized office buildings in the United States.

Pang, Zhihong↗
DOE OSTI2020

Evolving theories of change: Rethinking of the effects of office lighting on occupants

This paper proposes an overall theory of change that relates lighting in offices to a holistic view of human responses that contribute to the well-being of office workers. The theoretical model considers how variations in the four fundamental lighting attributes affect visual performance, visual environment, and non-image forming responses. It moves beyond these lighting to address how external factors that are may mediate the effects on the desired lighting related outcomes, which in turn determine the final impact on occupants. The model builds on prior conceptual models of lighting effects and informs design and research planning for office lighting. Ultimately, properly supported task performance can increase occupant motivation but by itself may not achieve the holistic desired impact. Lighting attributes that support a pleasant visual environment and appropriate non-image forming responses can more fully contribute to an occupant’s mood and overall well-being.

Collier, Jessica M.↗
DOE OSTI2023

Low power and privacy preserving sensor platform for occupancy detection

A low-cost, low-power, stand-alone sensor platform having a visible-range camera sensor, a thermopile array, a microphone, a motion sensor, and a microprocessor that is configured to perform occupancy detection and counting while preserving the privacy of occupants. The platform is programmed to extract shape/texture from images in spatial domain; motion from video in time domain; and audio features in frequency domain. Embedded binarized neural networks are used for efficient object of interest detection. The platform is also programmed with advanced fusion algorithms for multiple sensor modalities addressing dependent sensor observations. The platform may be deployed for (i) residential use in detecting occupants for autonomously controlling building systems, such as HVAC and lighting systems, to provide energy savings, (ii) security and surveillance, such as to detect loitering and surveil places of interest, (iii) analyzing customer behavior and flows, (iv) identifying high performing stores by retailers.

Velipasalar, Senem↗
DOE OSTI2022

A three-year dataset supporting research on building energy management and occupancy analytics

Abstract This paper presents the curation of a monitored dataset from an office building constructed in 2015 in Berkeley, California. The dataset includes whole-building and end-use energy consumption, HVAC system operating conditions, indoor and outdoor environmental parameters, as well as occupant counts. The data were collected during a period of three years from more than 300 sensors and meters on two office floors (each 2,325 m 2 ) of the building. A three-step data curation strategy is applied to transform the raw data into research-grade data: (1) cleaning the raw data to detect and adjust the outlier values and fill the data gaps; (2) creating the metadata model of the building systems and data points using the Brick schema; and (3) representing the metadata of the dataset using a semantic JSON schema. This dataset can be used in various applications—building energy benchmarking, load shape analysis, energy prediction, occupancy prediction and analytics, and HVAC controls—to improve the understanding and efficiency of building operations for reducing energy use, energy costs, and carbon emissions.

24 POWER TRANSMISSION AND DISTRIBUTION↗
NASA NTRS1996

Monitoring occupational exposure to cancer chemotherapy drugs

Reports of the health effects of handling cytotoxic drugs and compliance with guidelines for handling these agents are briefly reviewed, and studies using analytical and biological methods of detecting exposure are evaluated. There is little conclusive evidence of detrimental health effects from occupational exposure to cytotoxic drugs. Work practices have improved since the issuance of guidelines for handling these drugs, but compliance with the recommended practices is still inadequate. Of 64 reports published since 1979 on studies of workers' exposure to these drugs, 53 involved studies of changes in cellular or molecular endpoints (biological markers) and 12 described chemical analyses of drugs or their metabolites in urine (2 involved both, and 2 reported the same study). The primary biological markers used were urine mutagenicity, sister chromatid exchange, and chromosomal aberrations; other studies involved formation of micronuclei and measurements of urinary thioethers. The studies had small sample sizes, and the methods were qualitative, nonspecific, subject to many confounders, and possibly not sensitive enough to detect most occupational exposures. Since none of the currently available biological and analytical methods is sufficiently reliable or reproducible for routine monitoring of exposure in the workplace, further studies using these methods are not recommended; efforts should focus instead on wide-spread implementation of improved practices for handling cytotoxic drugs.

Review, Academic↗
DOE OSTI2022

How much have adverse occupational health outcomes among construction workers improved over time? Evidence from 25 years of medical screening

Background Construction workers have always had a high risk of occupational illnesses. We used 25 years of data from a medical screening program serving older construction workers to determine how much health outcomes have improved over the past 60 years. Methods We investigated changes in relative risk for chest radiographs consistent with pneumoconiosis, COPD by spirometry, lung cancer mortality, and audiometry-assessed hearing impairment among workers participating in a medical screening program. Results were stratified by decade of first construction employment: before 1960, 1960–1969, 1970–1979, 1980–1989, and after 1990. Poisson and Cox regression analyses assessed relative risk by decade adjusted for age, sex, smoking, and years of construction trade work. Results Subjects were 94% male and, on average, 60 years old with 25 years of construction work. When compared to workers employed before 1960, those first employed after 1990 experienced the following reductions in model-adjusted relative risks: chronic obstructive pulmonary disease, 32%; all pneumoconiosis, 68%; parenchymal abnormalities, 35%; pleural abnormalities, 71%; hearing impairment, 20%; and lung cancer mortality, 48%. Risks started to decline in the 1960s with greatest reductions among workers first employed after 1970. Conclusions This study demonstrates the positive impact that adoption of occupational health protections have had over the past 60 years. The greatest risk reductions were observed for outcomes with strong regulatory and legal incentives to reduce exposures and associated risks, such as those associated with inhalation hazards (asbestos and silica), while lowest improvement was for hearing impairment, for which little regulatory enforcement and few prevention incentives have been adopted.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Energy-saving potential evaluation for primary schools with occupant-centric controls

Recent studies demonstrated that there is significant energy-saving potential for primary schools, which heating, ventilation, and air-conditioning (HVAC) systems with occupant-centric control (OCC) is an excellent candidate to save energy. However, such an energy impact has yet to be evaluated for different climate zones as well as different energy code versions, but is critical for technology transfer and deployment. Therefore, this paper conducts comprehensive evaluation on the energy-saving potentials for the primary schools with two advanced OCC strategies: presence-based and counting-based. In this work, ninety-six building energy models with stochastic behavior of occupants are developed and simulated, which consist of two building energy code versions, 16 climate zones, and baseline case (without OCC) and two advanced cases (with OCC). To evaluate the energy saving potentials for OCC, primary schools in the U.S. are used as an example. The results show that there is significant energy-saving potential for primary schools by considering OCC strategies, especially the counting-based case. The energy-saving potential is up to 10.2% for presence-based OCC and 12.41% for counting-based OCC. Furthermore, both climate and code version have a significant impact on energy savings from OCC strategies. The energy-saving potentials vary from 1.79% to 12.41% for different climates and code versions. This evaluation can also contribute to quantify the nationwide energy saving potential for other countries.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Determination of Site Occupancy in the M–Pd–Zn (M = Cu, Ag, and Au) γ-Brass Phase by CALculation of PHAse Diagrams Modeling and Rietveld Refinement

The Pd–Zn γ-brass phase provides exciting opportunities for synthesizing site-isolated catalysts with precisely controlled Pd active site ensembles. Introducing a third metallic element into the γ-brass lattice further perturbs the catalytic active site ensembles. Here, in this work, we introduce coinage metallic elements M (M = Cu, Ag, and Au) into the Pd–Zn γ-brass phase and investigate the site occupation factors of each element in the γ-brass lattice. The CALculation of PHAse Diagrams (CALPHAD) modeling approach supported by energetics predicted by the density functional theory and X-ray and neutron diffraction with Rietveld refinement were used to identify the SOF on each Wyckoff site for various M amounts alloyed into the Pd–Zn γ-brass phase. The present analysis unveils the strong preference for Pd occupying the outer tetrahedral (OT) site in the γ-brass lattice, while the coinage metallic elements tend to substitute for Zn on the octahedral (OH) site. The determination of site occupancy in the bulk M–Pd–Zn γ-brass phase provides opportunities to investigate and tailor potential catalytically active site ensembles in the γ-brass phase materials.

36 MATERIALS SCIENCE↗
DOE OSTI2020

An efficient random-sampling method for calculating double occupancy of Gutzwiller wave function in single-band 1D and 2D lattices

In this paper, we report a random sampling method for computing the expectation value of physical quantities based on the Gutzwiler variational wave function. As the first application, we calculated the double occupancy, which is a critical quantity for under- standing the correlation effects in many-body systems, for single-band 1D and 2D lattices. We demonstrated that the random sampling scheme is more efficient than an existing Metropolis Monte-Carlo algorithm. For the 1D Hubbard model with only nearest-neighbor hopping, our results are almost identical to the exact analytic solution. We have also studied systems to which analytic solutions are not available, including the 1D lattices with next-nearest-neighbor hopping and 2D lattices. In addition, constraints on real-space con gurations can be easily implemented in the current scheme to further improve the Gutzwiller wave function. As an example, we calculated the double occupancy for 1D Hubbard model by applying the constraint that all double-occupied sites are paired with an empty site. With enhanced correlation between double-occupied and empty sites, the constraint results in much improved ground-state energy for 1D Hubbard model with strong on-site repulsion.

74 ATOMIC AND MOLECULAR PHYSICS↗
NASA NTRSDate not supplied

An Overview of LO-DuSST (Lunar Occupancy Dust Surface Separation Technologies) Objectives

Of the myriad of issues facing lunar exploration and maintaining an extended lunar presence, lunar dust is possibly the most pervasive. These jagged, chemically reactive, electrostatically charged, sometimes magnetic particles can impact every aspect of a lunar surface mission ranging from abrading extra-vehicular activity (EVA) suits to disrupting lunar vehicle thermal management systems to impeding efficacy of excavation equipment to impacting lunar inhabitant health. NASA’s Lunar Occupancy Dust Surface Separation Technologies (LO-DuSST) task, as a part of the broader Lunar Surface Innovation Initiative (LSII) project, seeks to implement synergistic active and passive lunar dust management and mitigation technologies for an array of applications. One such application is protection of power generation capabilities via solar panel arrays. Plasma dust lofting coupled with a piezoelectric-driven vibration technology will be demonstrated on solar panel surfaces contaminated with lunar dust simulant. Intrinsically low adhesion coatings will be applied to these surfaces to enhance dust removal. Electrostatic repulsion in confined geometries and materials to manage high velocity lunar dust wear will also be investigated. Collectively, these active and passive mitigation technologies will facilitate lunar surface operations including occupancy logistics, landing pad operations, power generation, and transportation. Initial results regarding lunar simulant-contaminated solar panel performance experiments, dust lofting using an electron beam, surface interactions of high velocity lunar dust arising from lunar lander plume-surface interactions, and lunar dust simulant-material interaction experiments will be discussed.

Lunar dust↗
DOE OSTI2021

Protecting building occupants against the inhalation of outdoor-origin aerosols

During normal operations, buildings can protect their occupants from outdoor airborne particle hazards of all types, including airborne pollutants. A long-term international research effort has advanced our knowledge of building protection physics. Recently we have developed an operationally efficient, regional-scale methodology - Regional Shelter Analysis - to account for both building protection effects and the typical distribution of people in and among buildings. To provide input to this capability, we estimate here the degree of protection afforded by the currently existing US building stock. Here, we first assemble and summarize the published literature relevant to indoor particle losses including (a) deposition to indoor surfaces, (b) losses that occur when particles penetrate through the building envelope, and (c) heating, ventilation and air conditioning (HVAC) system filtration efficiencies as well as general building operating conditions. Building protection against inhaling particulate hazards varies strongly, by orders of magnitude, according to particle size, airborne particle loss rate, and to a lesser extent building use (occupancy). Protection increases modestly as particle size increases from 0.1 to 1 μm and significantly as particle size increases from 1 to 10 μm. Model results are placed in context with previously reported measurements. Suggestions for future work, including enhanced validation datasets are provided.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗