SEARCH · Engineering Papers

Results for “Occupational”

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.

SourceResearch connectionFrom yearThrough year

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

At least 37 records · Page 2

All sources NASA NTRS DOE OSTI

NASA NTRSDate not supplied

Study of Advanced Occupant Models to Quantify Injury Risk for eVTOL Vehicles

Urban transportation is currently evolving from traditional ground-based vehicles (cars, taxis, and buses) to include air-based electric vertical take-off and landing (eVTOL) vehicles which can be utilized for on-demand transportation, cargo transport, and emergency services. These new eVTOL vehicles are designed to be small, lightweight, and able to operate autonomously without user intervention. Safety is a big part of eventual eVTOL adoption, however gaps in the consideration of safety features exist. Anthropomorphic test devices (ATDs) are used in aerospace crashworthiness standards to quantify occupant injury risk and develop improved safety designs for emergency landing situations, but the ATDs currently used in aircraft certification requirements were developed many decades ago. Developments have occurred over the years involving ATD technology, which includes a host of newer and more biofidelic ATDs such as the Test Device for Human Occupant Restraint (THOR). Increased computing power has also allowed for detailed computational human body models (HBMs) to be created, such as the Global Human Body Model Consortium (GHBMC). This study aims to assess the capability of both HBMs and new ATD designs to identify injury mechanisms within eVTOL relevant emergency landing conditions. Finite element (FE) analysis was used to expand upon full-scale and seat level impact testing conducted by researchers at the National Aeronautics and Space Administration (NASA) to look at effects of occupant model configurations on prediction of injury. The GHBMC HBM and THOR ATD models were simulated in the seat level test conditions to characterize differences between these advanced assessment tools and traditional ATDs in the isolated seat loading environment. Results identified key differences in the responses from each of the models utilized and compared their impact response in head, neck, and spinal injury metrics. The THOR model identified potential risks for head injuries due to head impacts on the seat, however it predicted lower spinal loads than the other occupant surrogates. The GHBMC showed distinctly different biomechanical responses compared to the ATD. The GHBMC model is much more deformable than the ATDs and it exhibited higher distribution of forces and increased sensitivity to the duration of acceleration pulses. Both models incorporated into this study identified key mechanisms for injury that should be considered for passenger safety in the development of these novel aircraft. In addition, this study demonstrated the value of FE modeling for running a variety of complex human surrogates to identify potential injury mechanisms for consideration in regulation and development of new aircraft. Continued research in this field to improve validation these models will only lead to safer aircraft and more comprehensive safety measures.

Crashworthiness↗

NASA NTRSDate not supplied

Study of Advanced Occupant Models to Quantify Injury Risk for eVTOL Vehicles

Crashworthiness↗

DOE OSTI2024

Occupational Radiation Exposure Report for Calendar Year 2023

The U.S. Department of Energy Occupational Radiation Exposure Report for Calendar 2023 presents the results of analyses of occupational radiation exposures at the U.S. Department of Energy (DOE), including the National Nuclear Security Administration (NNSA) operations, during calendar year 2023. This report includes occupational radiation exposure data for over 80,000 DOE Federal employees, contractors, and subcontractors as well as members of the public who have worked in or entered controlled areas monitored for exposure to radiation. DOE publishes this annual report to provide DOE Management, Program Offices, workers, health physicists, and other stakeholders an evaluation of DOE-wide performance regarding compliance with Title 10 of the Code of Federal Regulations (CFR) Part 835, Occupational Radiation Protection (10 CFR 835) radiation exposure limits and adherence to as low as reasonably achievable principles. This report provides a discussion regarding radiation protection and exposure reporting requirements. It also includes calendar year (CY) 2023 information and analyses regarding aggregate, individual, site, DOE Program, transient individuals’ dose, as well as a historical review of DOE exposure data. DOE continues to be diligent in protecting its workers and the public from exposure to radiation from DOE operations as illustrated by the results contained in this report.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2026

A prototype cooling blanket for mitigating occupant overheating risk in a hot indoor environment: Modeling and assessments

Conventional ways of cooling a room or an entire house for occupant thermal comfort during summer consume a significant amount of energy and are vulnerable to overheating risk during power outages that lead to loss of cooling system operations. This study investigates a low-power cooling blanket, as a Personal Cooling System (PCS), that covers the upper human body for direct cooling during a five-day heat wave in a single-family house. A modeling framework is developed for evaluating the thermal and energy performance of the cooling blanket, which builds upon the co-simulation of three models: a house energy model, a personal thermal comfort model, and a cooling blanket model. Simulation results show that under the power outage scenario, the cooling blanket can greatly reduce the occupant heat stress with a reduction of daily hours of exceedance (discomfort hours defined as TSV>2) by up to 17.2 h (a 95.3 % improvement from the baseline power outage without the blanket). The cooling blanket, equipped with an innovative electrocaloric heat pump (COP as high as 10.1) consumes 6.31 W and can be operated by a portable battery for several days. The cooling blanket consumes only 0.28 % of the electricity of a central air-conditioning system running to provide cooling for the whole house during the five-day heatwave period. The findings justify further research of electrocaloric wearable PCS as low-power effective cooling to ensure thermal survivability of occupants during extreme indoor environments.

Electrocaloric heat pump↗

DOE OSTI2026

A practical control strategy for demand flexibility with ensured occupant comfort in grid-interactive efficient buildings

This study proposes a practical and simplified demand response (DR) control strategy from the perspective of grid-interactive efficient buildings (GEBs), aiming to secure demand flexibility while ensuring occupant thermal comfort. Focusing on summer on-peak periods, a linear demand response (LDR) strategy that integrates cooling setpoint adjustment and lighting dimming was designed, and its performance was quantitatively evaluated. A case study was conducted using EnergyPlus-based simulations for a U.S. DOE small office prototype building under summer on-peak weather conditions. Compared with a conventional rapid demand response (RDR) strategy, the proposed LDR approach gradually reduced electrical loads while maintaining occupant thermal comfort indices, including predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD), within acceptable comfort ranges. Quantitative analysis of demand flexibility using the grid-interactive impact index (GII) and the flexibility strength index (FSI) showed that the LDR strategy provided approximately 12.5% demand flexibility during DR periods and achieved an electricity cost reduction of about 8.8%. In addition, the results of the part-load ratio (PLR)-based cooling system performance analysis showed that, in the on-peak period, the LDR strategy exhibited improved cooling performance compared with the baseline. Overall, this study shows the potential of a practical DR control strategy that can simultaneously achieve occupant comfort and demand flexibility without relying on complex advanced control technologies.

Jung, Dong Eun↗

DOE OSTI2026

Modulating coordinate site occupancy in high-entropy spinel electrocatalysts

High entropy spinel oxides provide a versatile platform for electrocatalysis because multiple metal cations can be incorporated into a single crystalline lattice, enabling tunable electronic structures. However, controlling how these cations distribute between tetrahedral and octahedral coordination sites remains a major challenge, limiting rational catalyst design. Here, we modulate cation coordination site occupancy between tetrahedral and octahedral sites in a Co–Fe–Cr–Mn–Ni framework by introducing a sixth cation (Zn, Ga, Mg, or Al) with distinct site preference energies. Using density functional theory, synchrotron X-ray absorption spectroscopy, and magnetic circular dichroism, we demonstrate that Zn preferentially occupies tetrahedral sites, driving increased octahedral occupancy of cobalt. This redistribution increases the population of octahedrally coordinated cobalt in mixed oxidation states, enhances electrical conductivity, and improves oxygen evolution reaction activity. Our findings establish coordination site occupancy as a critical design parameter, providing a strategic pathway for tailoring multicomponent spinel electrocatalysts with optimized performance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2025

Simultaneous occupancy of Cu C and Cu D in the ammonia monooxygenase active site

Ammonia monooxygenase (AMO), a copper-dependent membrane enzyme, catalyzes the first and rate-limiting step of nitrification: the oxidation of ammonia to hydroxylamine. Despite its central role in the global nitrogen cycle and its biotechnological relevance, structural characterization of AMO has lagged behind that of its homolog, particulate methane monooxygenase (pMMO), due to the slow growth rates of ammonia-oxidizing bacteria and the instability of AMO upon purification. Recent cryoEM studies of Nitrosomonas europaea AMO and Methylococcus capsulatus (Bath) pMMO in native membranes revealed new structural features, including two adjacent copper-binding sites in the transmembrane region, Cu C and Cu D , believed to constitute the active site. Although multiple structures were determined under various conditions, simultaneous occupancy of Cu C and Cu D was never observed, leaving their potential functional interplay unresolved. Here we report the 2.6 Å resolution cryoEM structure of AMO from Nitrosospira briensis C-128 in isolated native membranes. This structure reveals the first instance of simultaneous copper occupancy of the Cu C and Cu D sites, along with occupancy of the periplasmic Cu B site. Electron paramagnetic resonance (EPR) spectroscopic data indicate that the Cu B site is primarily occupied by Cu(II), while Cu C and Cu D are primarily occupied by diamagnetic ions, presumably Cu(I). Notably, a lipid molecule is bound between the Cu C and Cu D sites, separating them by ∼8.0 Å. The results underscore the importance of studying these enzymes in their native environments across species to resolve conserved and divergent molecular features.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2025

Hot, Cold, or Just Right? Using a Wide-View Infrared Biometric Sensor to Improve Occupant Comfort and Reduce Overcooling in Buildings via Closed-loop Control (CRADA Final Report)

This research adds to the understanding of building energy management by fundamentally challenging the long-standing paradigm of controlling an environmental parameter—air temperature—and assuming occupant comfort will follow. The project developed and demonstrated a novel approach that directly senses physiological indicators of human comfort to enable closedloop, human-centric control of heating, ventilation, and air conditioning (HVAC) systems. This work shifts the focus from open-loop environmental control to a closed-loop system that prioritizes the occupants' actual thermal state. The primary benefit to the public is the potential for a simultaneous improvement in the quality of indoor environments, where people spend most of their time, and a significant reduction in national energy consumption. Overcooling, or the overuse of cooling energy in a way that discomforts occupants, wastes approximately 0.5 Quads of primary energy annually in U.S. commercial buildings and creates unproductive indoor environments.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2025

Respiration Signal Pattern Analysis for Doppler Radar Sensor with Passive Node and Its Application in Occupancy Sensing of a Stationary Subject

Doppler radar node occupancy sensors are promising for applications in smart buildings due to their simple circuits and price advantage compared to quadrature radar sensors. However, single-channel sensitivity limitations may result in low sensitivity and misinterpreted motion rates if the detected subject is at or close to “null” points. We designed and tested a novel method to eliminate such limits, demonstrating that passive nodes can be used to detect a sedentary person regardless of position. This method is based on characteristics of chest motion due to respiration, found via both simulations and experiments based on a sinusoidal model and a more realistic model of cardiorespiratory motion. In addition, respiratory rate variability is considered to distinguish a true human presence from a mechanical target. Sensor node data were collected simultaneously with an infrared camera system, which provided a respiration signal reference, to test the algorithm with 19 human subjects and a mechanical target. The results indicate that a human presence was detected with 100% accuracy and successfully differentiated from a mechanical target in a controlled environment. The developed method can greatly improve the occupancy detection accuracy of single-channel radar-based occupancy sensors and facilitate their adoption in smart building applications.

Song, Chenyan↗

DOE OSTI2024

StOKeDMD: Streaming Occupation kernel dynamic mode decomposition

Dynamic mode decomposition (DMD) has become a common technique for constructing surrogate models for dynamical systems from observed system states. The Occupation Kernel DMD (OKDMD) method proposed in (Rosenfeld et al., 2022) and (Rosenfeld et al., 2024) is a Liouville operator based method that builds surrogate models from system state trajectories. Here, this paper proposes an extension of OKDMD to the case when the system states are observed in a streaming fashion, i.e., only a small fraction of the state trajectory is available at a given time. The developed method, Streaming Occupation Kernel DMD (StOKeDMD), accommodates the streaming data input by leveraging properties of specific choices of kernel functions and occupation kernels. We apply the StoKeDMD method as a compression method for streaming data, analyze the memory complexity, and demonstrate the performance of StoKeDMD in the compression of streaming data generated from a Lorenz system and a fluid flow simulation.

97 MATHEMATICS AND COMPUTING↗

NASA NTRS1975

An improved human display model for occupant crash simulation programs

An improved three-dimensional display model of a human being which can be used to display the results of three-dimensional simulation programs that predict the positions of an occupant during impact of a vehicle was presented. The model allows the user to view the occupant from any orientation in any position during the crash. The display model assumes the usual break up of the body into rigid segments which is normal for occupant crash simulation programs, but the shape of the segments in the display model are not necessarily the same as those used in the crash simulation. The display model is proportioned so as to produce a realistic drawing of the human body in any position. Joints connecting the segments are also drawn to improve realism.

Willmert, K. D.↗

NASA NTRS1976

Developing space occupancy - Perspectives on NASA future space programme planning

NASA planning aspects of potential future manned space flight missions are examined and the necessity of long-range planning is pointed out. A listing of desirable future activities is considered, taking into account the permanent occupancy of near-earth orbit space, the permanent occupancy of earth-moon space, the full self-sufficiency of man in geolunar space, and the permanent occupancy of heliocentric space. The technological requirements for the considered activities are discussed, giving attention to transportation, habitation, engineering technology, life sciences, operations technology, and advanced management concepts. A description of future program phasing and advanced studies requirements is also given.

Von Puttkamer, J.↗

NASA NTRS1977

Developing space occupancy - Perspectives on NASA future space program planning

Potential future manned space flight missions for the time after the development of the space transportation system with the space shuttle are considered, taking into account a sequence of activities concerning a gradually increasing penetration of space by man. The activities are related to the permanent occupancy of near-earth space, the permanent occupancy of near-moon space, the full self-sufficiency of man in earth-moon space, and the permanent occupancy of heliocentric space. Attention is given to Mars orbiting stations, the exploration of the asteroids, comet exploration, planet engineering programs, heliocentric orbit installation, the evolution of the earth orbit space community, space industrialization technology, lunar base development, and evolutionary paths to far-future space endeavors.

Von Puttkamer, J.↗

NASA NTRS1980

Prototype Input and Output Data Elements for the Occupational Health and Safety Information System

The National Aeronautics and Space Administration plans to implement a NASA-wide computerized information system for occupational health and safety. The system is necessary to administer the occupational health and safety programs and to meet the legal and regulatory reporting, recordkeeping, and surveillance requirements. Some of the potential data elements that NASA will require as input and output for the new occupational health and safety information system are illustrated. The data elements are shown on sample forms that have been compiled from various sources, including NASA Centers and industry.

Whyte, A. A.↗

NASA NTRS1999

Engineered Solutions to Reduce Occupational Noise Exposure at the NASA Glenn Research Center: A Five-Year Progress Summary (1994-1999)

At the NASA John H. Glenn Research Center at Lewis Field (formerly the Lewis Research Center), experimental research in aircraft and space propulsion systems is conducted in more than 100 test cells and laboratories. These facilities are supported by a central process air system that supplies high-volume, high-pressure compressed air and vacuum at various conditions that simulate altitude flight. Nearly 100,000 square feet of metalworking and specialized fabrication shops located on-site produce prototypes, models, and test hardware in support of experimental research operations. These activities, comprising numerous individual noise sources and operational scenarios, result in a varied and complex noise exposure environment, which is the responsibility of the Glenn Research Center Noise Exposure Management Program. Hearing conservation, community noise complaint response and noise control engineering services are included under the umbrella of this Program, which encompasses the Occupational Safety and Health Administration (OSHA) standard on occupational noise exposure, Sec. 29CFR 1910.95, as well as the more stringent NASA Health Standard on Hearing Conservation. Prior to 1994, in the absence of feasible engineering controls, strong emphasis had been placed on personal hearing protection as the primary mechanism for assuring compliance with Sec. 29CFR 1910.95 as well as NASA's more conservative policy, which prohibits unprotected exposure to noise levels above 85 dB(A). Center policy and prudent engineering practice required, however, that these efforts be extended to engineered noise controls in order to bring existing work areas into compliance with Sec. 29CFR 1910.95 and NASA's own policies and to ensure compliance for new installations. Coincident with the establishment in 1995 of a NASA wide multi-year commitment of funding for environmental abatement projects, the Noise Exposure Management Program was established, with its focus on engineering approaches to reducing occupational and community noise exposure. The organization and mission of this Program were documented shortly after its inception, and individual programmatic components have been the subject of subsequent papers. This paper summarizes the status and accomplishments of the engineering aspects of the Program from a five-year retrospective viewpoint and includes a review of retrofit noise control solution strategies, which have not been previously documented.

Cooper, Beth A.↗

NASA NTRS2001

Proceedings from the 2001 NASA Occupational Health Conference: Risk Assessment and Management in 2001

This Conference convened approximately 86 registered participants of invited guest speakers, NASA presenters, and a broad spectrum of the Occupational Health disciplines representing NASA Headquarters and all NASA Field Centers. Two days' Professional Development Courses on Exposure Assessment Strategies and Statistics and on Advanced Cardiac Life Support training and recertification preceded the Conference. With the theme, 'Risk Assessment and Management in 2001,' conferees were first provided updates from the Program Principal Center Office and the Headquarters Office. Plenary sessions elaborated on several topics: biological terrorism, OSHA recordability, Workers' Compensation issues, Federal ergonomic standards, bridging aerospace medicine and occupational health-especially in management of risk in spaceflight, and EAP operations with mission failures. A keynote address dealt with resiliency skills for 21st century workers and two NASA astronaut speakers highlighted a tour of the Johnson Space Center. During discipline specific breakout sessions, current issues in occupational health management and policy, credentialing and privileging, health risk assessment, measurement and standardization, audits, database development, prevention and rehabilitation, international travel and infection control, employee assistance, nursing process, and environmental health were presented.

Roberson, Sheri↗

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.↗