Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “interview”

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 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Reproductive intentions among HIV-negative gay and bisexual men initiating pre-exposure prophylaxis in the Sustainable Health Center Implementation pre-exposure prophylaxis pilot study, 2014–2016

Introduction We assessed reproductive intentions and associated characteristics among men enrolled in the Sustainable Health Center Implementation pre-exposure prophylaxis (PrEP) Pilot (SHIPP) Study. Methods We analyzed baseline data from 1275 men who self-identified as gay or bisexual and participated in the SHIPP study. SHIPP was a cohort study of PrEP implementation in five community health centers in Chicago, Jackson, Philadelphia, and Washington, D.C. conducted from 2014 to 2016. Participants completed audio computer-assisted self-interviews querying intentions to have a child in the future. We estimated the association between participants’ reproductive intentions and their characteristics using Poisson regression models. Results Approximately 47% of participants indicated their intentions to have a child. Black/non-Hispanic (aPR = 1.40; 95% CI: 1.10–1.78) and other/non-Hispanic participants (aPR = 1.40; 95% CI: 1.01–1.93) were more likely to report intentions to have a child than white/non-Hispanic participants. Participants were less likely to report intentions to have children as age increased (18–29 years, reference group; 30–39 years, aPR = 0.80, 95% CI: 0.64–0.99; 40–49 years, aPR = 0.49, 95% CI: 0.33–0.72; 50+ years, aPR = 0.07, 95% CI: 0.02–0.21). Conclusions Clinicians offering PrEP to black and other/non-Hispanic gay and bisexual men should assess their reproductive intentions as family-planning counseling may be an opportunity to introduce PrEP to HIV-negative gay and bisexual men.

Immunology↗
DOE OSTI2023

The Cross-sectional and Longitudinal Association Between Thyroid Function and Depression: A Population-Based Study

Abstract Context An association of thyroid function with mood disorders has been widely suggested, but very few studies have examined this association longitudinally. Objective We assessed the cross-sectional and longitudinal association between thyroid function and depression in a population-based cohort. Methods A total of 9471 individuals were included in cross-sectional analyses, of whom 8366 had longitudinal data. At baseline, we assessed thyroid function using serum samples (thyrotropin [TSH], free thyroxine (FT4), and thyroid peroxidase antibodies) and depressive symptoms using the Centre for Epidemiologic Studies Depression (CES-D) scale. Incident depressive events (n = 1366) were continuously followed up with the CES-D and clinical interviews. We analyzed the cross-sectional association of thyroid function and thyroid disease with depressive symptoms using linear and logistic regression, and the longitudinal association with Cox proportional hazard models for depressive events. Results Lower TSH levels and lower and higher FT4 levels were cross-sectionally associated with more depressive symptoms with a B value of −0.07 per 1 unit increase of natural log-transformed TSH (95% CI −0.11; −0.04). Furthermore, hypothyroidism was cross-sectionally associated with less depressive symptoms and hyperthyroidism with more depressive symptoms. Longitudinally, there was a U-shaped association between FT4 and incident depressive events but only in euthyroid participants. Conclusion We show a cross-sectional association between thyroid (dys)function with depressive symptoms, and a U-shaped association between FT4 and incident depressive events in euthyroid individuals. Our findings suggest an association of thyroid function with the risk of developing depression, albeit small. Reverse causation and additional underlying factors may also contribute to the association.

Roa Dueñas, Oscar Hernando (ORCID:0000000207522261↗
DOE OSTI2026

Robotic automation of maintenance work in nuclear power plants a cross-sector survey and roadmap

Nuclear power plants face increasing cost pressures, workforce constraints (aging workforce and skilled labor shortages), and safety requirements that are accelerating interest in robotic systems for inspection and maintenance. We conducted semi-structured interviews with personnel from seven U.S. nuclear utilities and compared deployment models, operational use cases, and integration practices with those reported by participants in the oil, gas, and petrochemical sector. In nuclear plants, robotic use remains concentrated in inspection—particularly indoor unmanned aerial vehicles and submersible remotely operated vehicles—with limited application to physical maintenance tasks. Reported near-term value includes reduced radiological and industrial risk, reduced outage labor, and improved data for planning and condition assessment. Key barriers include integration and data-interoperability constraints, operator qualification requirements, cybersecurity review burden, and difficulty demonstrating reliability in plant-representative environments. Cross-sector benchmarking highlights organizational and deployment practices that may help nuclear plants scale from pilots to routine use. We propose a deployment-oriented roadmap emphasizing modular payload strategies, representative qualification pathways and testing environments, and improved data governance to support safe and economically justified expansion of robotics in operating nuclear power plants.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

Estimating the Contributions to Human Error Probability from the Convolution of the Distribution of Time Available and Time Required

As part of their duties, Human Reliability Analysis must often evaluate if crews in nuclear power plants (NPPs) can complete tasks associated with a human-failure event within time limits. For example, the time required in NPP scenarios is determined by systematic and structured walkthroughs, feasibility studies, recorded times from training exercises, and interviews with experienced operators and experts. Typically, a point estimate is derived for the estimate (mean, maximum, or 95th percentile of time required). Using point-estimate values can mask the risk associated with variability among crews, plant conditions and set-up, environmental conditions, and other impact factors under which these actions are executed. While point estimates for time required and time available have served the industry well, without considering the uncertainty they could lead to biased understanding about the risk. The Integrated Human Event Analysis System - General Methodology (IDHEAS-G) model (developed by the US Nuclear Regulatory Commission, NRC) for human error probability calculates human error probability by summing two probabilities: insufficient time and cognitive error. As such, the model takes a more holistic approach by considering the full distributions for time required and time available to calculate the human error probability because the time available to complete the task is insufficient. In this study, we expand on the work of the NRC and discuss methods for estimating these time considerations. For example, for the time required, the impact of Performance Influencing Factors (PIFs) on the distribution was divided into impacts that are aleatory in nature, such as crew-to-crew variability, and those that are epistemic (i.e., the PIFs). Starting with the factors that introduce aleatory uncertainty, a first-order distribution was developed from a large set of time required (i.e., NPP task completion times) data for the range of operator actions that occur in the NPP control room under simulated accident conditions. The first-order distribution can then be adjusted to account for epistemic uncertainty using research associated with the impact of applicable PIFs on the time required. We also develop guidance for analysts to address the probability distributions for the time available. The guidance we developed on how to estimate time required and time available distributions is based on the identification of pertinent research and data, data analyses, and expert knowledge elicitation.

human error probability, human performance, time e↗
DOE OSTI2026

2010-2012 California Household Travel Survey

The 2010-2012 California Household Travel Survey (CHTS) was administered by the California Department of Transportation, which collected demographic and travel behavior characteristics for residents across the entire state. At the time, it was the largest such regional or statewide survey ever conducted in the United States. Detailed travel behavior information was obtained from more than 42,500 households via multiple data-collection methods, including computer-assisted telephone interviewing, online and mail surveys, wearable (7,574 participants) and in-vehicle (2,910 vehicles) global positioning system devices, and on-board diagnostic sensors that gathered data directly from a vehicle's engine. Details of personal travel behavior were gathered within the region of residence, inter-regionally within the state, and in adjoining states and Mexico. The survey sampling plan was designed to ensure an accurate representation of the entire population of the state. The CHTS included additional features, such as vehicle-acquisition decisions, parking choices, work schedules and flexibility, use of toll lanes/priced facilities, and walk and bicycle trips, to support advanced model development.

1Hz data↗
DOE OSTI2026

2001-2002 Southern California Regional Travel Survey

The 2001-2002 Southern California Regional Travel Survey collected data on household characteristics and travel behavior to update regional travel demand models. It covered six counties including Imperial, Los Angeles, Orange, Riverside, San Bernardino, and Ventura. The Southern California Association of Governments contracted with NuStats Partners to conduct the survey following the 2000 decennial census. Survey data collection occurred in 2001 and 2002 using computer-assisted telephone interviewing and travel diaries. Roughly 17,000 households completed the survey. An additional global positioning system (GPS) sample was taken for the purpose of auditing the self-reported diaries. Battelle provided data collection support for the GPS sample.

1Hz data↗
DOE OSTI2026

1994 Treasure Coast Travel Characteristics Study

The Treasure Coast Travel Characteristics Study was initiated in January 1995 in order to improve the travel forecasting accuracy of the Florida Standard Urban Transportation Model System for this area. The main objective of the surveys was to establish the socioeconomic and travel characteristics of the Treasure Coast Area of Mart, St. Lucie, and Indian River Counties. A total of 1,531 households participated in the study. The household study was separated into multiple parts: one used phone interviews to collect data and another provided travel logs for study participants to fill out, ranging from one- to three-day logs.

1Hz data↗
DOE OSTI2026

1982 The Twin Cities Metropolitan Area Travel Behavior Inventory

The purpose of the 1982 Travel Behavior Inventory was to update socioeconomic and travel data gathered in a 1970 home interview survey. The area in Minnesota studied included the counties of Ramsey, Hennepin, Dakota, Anoka, Washington, Carver, and Scott. The inventory collected demographic and travel data from September 1, 1982, to February 27, 1983. The survey contains data from 2,640 participating households. From participants' travel records, a total of 21,944 trips were reported by 6,059 household members for a 24-hour period.

1Hz data↗
DOE OSTI2026

2000 The Twin Cities Metropolitan Area Travel Behavior Inventory

The 2000 Twin Cities Metropolitan Area Travel Behavior Inventory, conducted by Twin Cities Metropolitan Council—Saint Paul, was the first major travel survey in the region since 1990. The 2000 inventory includes a home interview survey, an establishment survey, a transit survey, external station traffic counts, and an external station origin/destination survey. The study area under the household inventory survey included the seven counties of the regional Metropolitan Planning Organization and thirteen adjacent counties. Demographic, socioeconomic, and travel data were gathered for 6,386 households. Of these, 6,219 households completed the travel logs, which includes household members older than five years old.

1Hz data↗
DOE OSTI2026

1988 Delaware Valley Regional Planning Commission Household Travel Survey

The Delaware Valley Regional Planning Commission conducted household travel surveys in 1988 for the Delaware Valley region of Pennsylvania, which consists of Bucks, Chester, Delaware, Montgomery, and Philadelphia counties. The home interview travel survey was intended to measure the travel habits of area residents, and it generated needed information on trip generation rates, trip distribution, and model choice. This information was used for model calibration and validation on the trip generation, trip distribution, and model split models. The data includes demographic and socioeconomic details, as well as travel patterns, for 1,567 households. A total of 5,733 people reported a total of 18,899 trips. The survey was conducted on a weekday, Monday through Friday, and only ten survey locations contained weekend day travel.

1Hz data↗
DOE OSTI2026

1981 Bay Area Metropolitan Transportation Commission Household Survey

The San Francisco Bay Area's Metropolitan Transportation Commission (MTC) conducted the study in 1981, collecting household and travel information by telephone from 6,209 households in the MTC's nine-county jurisdiction. The sample gave good geographic coverage and provided a good representation of the population groups in the Bay Area. The survey was primarily intended to measure weekday travel; however, the size of the weekend travel sample was sufficient to enable MTC to make inferences about weekend trip generation. Travel days in the sample were spread out evenly over the three-month interviewing period to eliminate seasonal bias.

1Hz data↗
DOE OSTI2026

1990 Seattle Household Travel Survey Wave 2

The Seattle Household Travel Survey Wave 2, conducted in 1990, was the second wave in a 10-part longitudinal panel survey of the travel patterns of households in the Puget Sound region of Washington state. The survey series was initiated in 1989 by the Puget Sound Regional Council. Data collection for the second wave took place in the fall of 1990, which included full interviews and travel diaries, as well as some panel refreshment. Demographic and work trip data updates, but no travel diaries, were gathered for 2,023 households in four counties in the Seattle area. The survey relied on the willingness of study area residents to 1) provide demographic information about their household, its members, and its vehicles; 2) document all travel for each household member, aged 15 years or older, for an assigned two-day period; and 3) agree to participate in additional survey waves. After an initial telephone screening, survey participants received mailed travel diaries to aid in documenting travel information for the two-day assessment period. Respondents were instructed to record their mode of transportation, trip purpose, number of passengers, departure and arrival times, ride fare, and parking costs. Demographic information for this study includes age, gender, education, employment status, and household income.

1Hz data↗
DOE OSTI2026

2002 St. Louis Region Travel Survey

The 2002 St. Louis Household Travel Survey entailed the collection of weekday travel behavior characteristics of households residing in each of the eight counties that comprise the St. Louis region. In addition to collecting basic demographic and socioeconomic information about each household and its members, the survey documented specific characteristics of activities and trips, including the number and purpose of trips, trip duration, time of day, mode of transportation, and specifics of school- and work-related travel. The survey instruments contained three components: 1) the recruitment questionnaire, 2) the travel log, and 3) the retrieval questionnaire. In total, 7,046 households were recruited to participate in the study via telephone interview. Of these, 5,094 completed travel logs during a specific 24-hour period, and the information was retrieved from all household members, regardless of age. Demographic information for this study includes age, gender, education level, employment status, and household income.

1Hz data↗
DOE OSTI2023

Chelation Modeling of a Plutonium-238 Inhalation Incident Treated with Delayed DTPA

This work describes an analysis, using a previously established chelation model, of the bioassay data collected from a worker who received delayed chelation therapy following a plutonium-238 inhalation. The details of the case have already been described in two publications. The individual was treated with Ca-DTPA via multiple intravenous injections and then nebulizations beginning several months after the intake and continuing for four years. The exact date and circumstances of the intake are unknown. However, interviews with the worker suggested that the intake occurred via inhalation of a soluble plutonium compound. The worker provided daily urine and fecal bioassay samples throughout the chelation treatment protocol, including samples collected before, during, and after the administration of Ca-DTPA. Unlike the previous two publications presenting this case, the current analysis explicitly models the combined biokinetics of the plutonium-DTPA chelate. Further, using the previously established chelation model, it was possible to fit the data through optimizing only the intake (day and magnitude), solubility, and absorbed fraction of nebulized Ca-DTPA. This work supports the hypothesis that the efficacy of the delayed chelation treatment observed in this case results mainly from chelation of cell-internalized plutonium by Ca-DTPA (intracellular chelation). It also demonstrates the validity of the previously established chelation model. As the bioassay data were modified to ensure data anonymization, the calculation of the “true” committed effective dose was not possible. However, the treatment-induced dose inhibition (in percentage) was calculated.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗
DOE OSTI2021

Persistent, “Mysterious” Seismoacoustic Signals Reported in Oklahoma State during 2019

Here, we report on the source of seismoacoustic pulses that were observed across the state of Oklahoma (OK) during summer of 2019, and the subject of national media coverage and speculation. Seismic network data collected across four U.S. states and interviews with witnesses to the pulse’s effect on residential structures demonstrate that they were triggered by routine ammunition disposal operations conducted by McAlester Army Ammunition Plant (McAAP). During these operations, conventional explosives destroy obsolete munitions stored in pits through a controlled sequence of electronically timed shots that occur over tens of minutes. Despite noise-abatement efforts that reduce coupling of acoustic energy with air, some lower frequency, subaudible (infrasonic) sound radiates from these shots as discrete pulses. We use nine months of blast log documents, seismic network records, analyst picks, and physical modeling to demonstrate that seismic stations as far as 640 km from McAAP sample these pulses, which record seasonal patterns in stratospheric and tropospheric winds, as well as the dynamic formation of waveguides and shadow zones. Digital short-term average to long-term average detectors that we augment with dynamic thresholds and time-binning operations identify these pulses with a fair probability, when compared with visual observations. Our analyses thereby provide estimates of observation rates for both partial and full sequences of these pulses, as well as single shots. We suggest that disposal operations can exploit existing, composite seismic networks to predict where residents are likely to witness blasting. Crucially, our data also show that dense seismic networks can record multiscale atmospheric processes in the absence of infrasound arrays.

58 GEOSCIENCES↗
DOE OSTI2022

Market Barriers and Drivers for the Next Generation Fault Detection and Diagnostic Tools

Commercial buildings in the U.S. consume as much as 30% excess energy compared to buildings that operate fault free and efficiently. Fault detection and diagnostic (FDD) platforms help to continually identify operational inefficiencies and maintain low-carbon performance. However, the recommendations generated by FDD tools need to be implemented by technicians, resulting in delays or lost savings opportunities. Recent research advances showed fault AUTOcorrection integrating with commercial FDD offerings filled this gap. Seven innovative AUTOcorrection algorithms were integrated into two FDD platforms and deployed across four buildings. The enhanced tools successfully correct faults focusing on incorrectly programmed schedules, override not released, control hunting, rogue zone, and suboptimal setpoints. Although its technical efficacy has been proven in the field, fault AUTO-correction is still early in the deployment cycle and opportunities and barriers need to be understood to reach its full potential in market transformation. This paper broadly introduces the new technology that automatically corrects HVAC faults. The authors describe in detail technology potential, market barriers, and enablers for scalability based on field testing results and interviews with the FDD providers and facility managers. The interviewees agreed that AUTO-correction can reduce the extent to which savings are dependent upon human intervention, scale building operators’ ability to act on FDD findings (especially for facilities with small operation teams), and achieve significant savings. To enable scalable deployment, future efforts are needed to overcome the barriers such as cybersecurity and accountability concerns from building operators and standardization of control parameters used in building automation systems.

Pritoni, Marco↗
DOE OSTI2021

Market Brief: Customer-sited Distributed Energy Resources

This market brief summarizes key takeaways from interviews with vendors and service providers in one or more areas of the DER market: DER controls, battery storage, solar photovoltaic, thermal energy storage, combined heat and power, flexible building loads, and electric vehicle charging. Back-up generators used only in emergencies are not in the scope of this market brief.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2020

Dragonstone Strategy – State of Cybersecurity in the Oil & Natural Gas Sector

The oil & natural gas (ONG) system touches every corner of the nation and increased communications & control capabilities have not only allowed for greater efficiency of system operation, but have also created a massive target for adversaries to launch cyber-attacks. Like any other heavy industrial process, the ONG system relies on a complex system of information technology (IT) and operational technology (OT) devices. The current state of cyber-preparedness across the ONG industry varies from organization to organization. Among the most common challenges that ONG companies face are remote locations, longlived field assets, and lacking capabilities to find and track malware on their systems. ONG companies tend to be concerned with lack of cyber-awareness from employees, risk stemming from remote access for operations & maintenance, and software vulnerabilities within third-party equipment. Various industry and government organizations are performing research and development activities to address some of these challenges, but in many cases industry stakeholders are not aware of solutions that already exist. It is clear that a need exists for a coherent, comprehensive, multi-layered strategy for assuring the security and resilience of the nation's pipeline infrastructure against cyber threats. For a variety of reasons, the general consensus from stakeholders interviewed by LLNL is that the state of cyber-security within the electric grid is currently outpacing its ONG cousin. Existing strategies for the resilience and cyber-security of the electric grid can and should be leveraged to provide immediate benefits to the ONG system. In LLNL’s view, there are two key factors currently limiting the development of necessary cyber-practices within the ONG industry: The sheer number of differing regulatory bodies and trade groups offering both standards and best-practice recommendations for ONG cyber-security makes it difficult to create a comprehensive, directed, and coherent strategy that is applicable to all players within the ONG industry. The ONG industry is unaware of potentially useful technologies that have been developed for ensuring cyber-security of other infrastructure systems, such as the electric grid. Leveraging these technologies—and the science and engineering behind them—can provide some low-hanging fruit that can greatly improve cyber-security in the ONG industry without significant investments in terms of time and money. In the months following this report, LLNL will continue to perform outreach to key oil & gas industry stakeholders in a continual effort to identify the most pressing cyber-resilience issues in the industry. This outreach will be supplemented with LLNL’s threat intelligence capabilities to begin painting a clearer picture of the overall threat landscape faced by this sector. This assessment will be threat-informed and while the strategy itself will not be classified we will leverage intelligence analysis and adversary capabilities to identify gaps in current cybersecurity practices for oil & gas pipeline systems. Recommended efforts will be compiled into a cyber-resilience roadmap for the oil & gas pipeline sector, in which LLNL will highlight priority activities to immediately improve the state of cyber-resilience in the industry.

02 PETROLEUM↗