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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Cooperative Automated Cohort Driving on Connected Infrastructure, Arterial Roadways, and Highways: Final Project Demonstration and System-of-Systems Model Correlation

This project seeks to synergize vehicle automated driving and connectivity data to improve mobility and energy efficiency of groups of mixed vehicles operating in close proximity (vehicle cohort) on various infrastructure. A custom cellular communication network links vehicles operating as a cohort with infrastructure to a centralized system-of-systems digital twin with an AI-based optimal behavior planner. The data contained in this set are from final testing and technology demonstrations to U.S. Department of Energy staff at the American Center for Mobility. The data contain single-lane, single-light scenarios; multi-lane, multi-light arterial scenarios; and limited-access highway scenarios. All test cases were derived from simulations and replicated on the test track. The project employed two and four light-duty vehicles with connectivity and drive automation for the testing. The baseline scenario without connectivity was run under the control of the system-of-systems centralized planner but operating each vehicle with an intelligent driver model controlling the velocity, lane utilization, and vehicle gap. This was to ensure the highest compatibility with the simulation in terms of dynamic behavior. The connected cohort case utilized AI optimization to perform coordinated and cooperative control for energy, as well as safe, comfortable behavior for the cohort. The dataset is appropriately named with unconnected and connected designations, with comparisons sharing the same run index number. The included PowerPoint and PDF files describe the test setup and provide an overview of results from the project. ![image](de-EE0009209_March_2023_Data_Arterial_Scenario_Results.png)

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2026

1998 North Front Range (NFR) MPO

The North Front Range Travel Survey was a comprehensive study of travel behavior throughout the north front range of Colorado. The primary purpose of the survey was to provide a picture of travel patterns and characteristics of travelers in the Denver region. The survey was part of four primary surveys under the Regional Travel Behavior Inventory—a collaborative effort among the Denver Regional Council of Governments in partnership with the Regional Transportation District, the Colorado Department of Transportation, and the Regional Air Quality Council. The survey, conducted from October to January, provided demographic and household-based trip information for household members age 16 and older from 13,348 households. A 24-hour travel diary was provided to respondents to record their travel.

1Hz data↗
DOE OSTI2026

1994 SEMCOG Household-Based Person Trip Survey

The Southeast Michigan Council of Governments contracted with the Applied Management & Planning Group to conduct a travel behavior survey of 7,361 households from March 28, 1994, to June 10, 1994. The primary purpose of this study was to provide the council with a new database of travel behavior to assist in updating the region's transportation models. This data collection includes demographic, socioeconomic, travel, and mobile source emissions models for projecting future patterns of development, travel, congestion, and air pollution. Information about household characteristics and travel was collected using a one-day, activity-focused diary and a separate household survey. In an activity diary, respondents recorded 65,535 trips during the assigned the day.

1Hz data↗
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 KIPDA Regional Household Travel Survey

The Kentuckiana Planning and Development Agency (KIPDA) conducted this four-month study from October 2000 through January 2001 to update regional travel demand models. The universe for the survey consisted of households in the five-county Louisville transportation planning study area, including Clark and Floyd counties in Indiana and Bullitt, Jefferson, and Oldham counties in Kentucky. Demographic variables and travel behavior characteristics were collected for 4,433 households in a 24-hour period. Of these, 4,113 were completed with households that were selected at random, and the remaining 320 were completed with representatives. The data from the survey only reflect travel by the selected residents of the five counties listed above and do not account for travel in the region by persons who were not residents of those five counties.

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DOE OSTI2026

1990 CATS Household Travel Survey

The Chicago Area Transportation Study (CATS) 1990 Household Travel Survey was a self-administered mail-out mail-back survey. The purpose of the study was to update existing data on travel patterns and characteristics of Chicago residents. CATS surveyed the region on a county-by-county basis with the Chicago Central Business District in collaboration with the Urban Transportation Center of the University of Illinois. The study gathered demographic and travel behavior data from residents of northeastern Illinois who were 14 years old or older. 19,314 households participated in the survey. The study focused on non-work travel by motorized vehicle and by foot, and residents recorded their trips on a single travel day. Transportation-related variables include trip origin and destination, trip purpose, travel time, mode of travel used, vehicle occupancy, and walking distance (if that transit mode was involved).

1Hz data↗
DOE OSTI2022

Magnus induced diode effect for skyrmions in channels with periodic potentials

Using a particle based model, we investigate the skyrmion dynamical behavior in a channel where the upper wall contains divots of one depth and the lower wall contains divots of a different depth. Under an applied driving force, skyrmions in the channels move with a finite skyrmion Hall angle that deflects them toward the upper wall for -x direction driving and the lower wall for +x direction driving. When the upper divots have zero height, the skyrmions are deflected against the flat upper wall for -x direction driving and the skyrmion velocity depends linearly on the drive. For +x direction driving, the skyrmions are pushed against the lower divots and become trapped, giving reduced velocities and a nonlinear velocity-force response. When there are shallow divots on the upper wall and deep divots on the lower wall, skyrmions get trapped for both driving directions; however, due to the divot depth difference, skyrmions move more easily under -x direction driving, and become strongly trapped for +x direction driving. Further, the preferred -x direction motion produces what we call a Magnus diode effect since it vanishes in the limit of zero Magnus force, unlike the diode effects observed for asymmetric sawtooth potentials. We show that the transport curves can exhibit a series of jumps or dips, negative differential conductivity, and reentrant pinning due to collective trapping events. We also discuss how our results relate to recent continuum modeling on a similar skyrmion diode system.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2024

Laser-induced quenching of metastability at the Mott insulator to metal transition

There is growing interest in strongly correlated insulator thin films because the intricate interplay of their intrinsic and extrinsic state variables causes memristive behavior that might be used for biomimetic devices in the emerging field of neuromorphic computing. Here, in this study, we find that laser irradiation tends to drive V 2 ⁢O 3 from supercooled/superheated metastable states toward thermodynamic equilibrium, most likely in a nonthermal way. We study thin films of the prototypical Mott-insulator V2⁢O3, which show spontaneous phase separation into metal-insulator herringbone domains during the Mott transition. Here, we use low-temperature microscopy to investigate how these metal-insulator domains can be modified by scanning a focused laser beam across the thin film surface. We find that the response depends on the thermal history: When the thin film is heated from below the Mott transition temperature, the laser beam predominantly induces metallic domains. On the contrary, when the thin film is cooled from a temperature above the transition, the laser beam predominantly induces insulating domains. Very likely, the V 2 ⁢O 3 thin film is in a superheated or supercooled state, respectively, during the first-order phase transition, and the perturbation by a laser beam drives these metastable states into stable ones. This way, the thermal history is locally erased. Our findings are supported by a phenomenological model with a laser-induced lowering of the energy barrier between the metastable and equilibrium states.

Materials Science↗
DOE OSTI2025

Supramolecular bending and twisting in the hierarchical self-assembly of monodisperse mesogenic oligomers

Understanding how different forms of supramolecular curvature arise during assembly is crucial to designing and tuning the microstructure of hierarchically self-assembled materials. Here, we show that in crystalline phases of mesogenic oligomers, the oligomer length is a critical parameter that determines the type of curvature (Gaussian or cylindrical) exhibited by the self-assembled structures. We use iterative exponential growth to synthesize monodisperse mesogenic oligomers ranging from dimer to octamer. By analyzing their phase behavior and microstructure, we elucidate how length-dependent thermodynamic and kinetic effects tune their hierarchical degree of ordering. The oligomers’ length-dependent crystalline order drives the formation of scrolled sheets in shorter oligomers and twisted ribbons in longer oligomers. These studies highlight how oligomer length interplays with mesogen geometry and crystalline packing to drive self-assembly, introducing oligomer length as a powerful design parameter toward tailored applications of mesogenic systems.

36 MATERIALS SCIENCE↗
NASA NTRS1973

Models for compact pulsing X-ray sources.

Development of a model of a neutron star (Cen X-3) which releases the infall energy of accreted matter. Some general remarks are made on the possibility of accretion as a source of energy. It is shown that overflow of the Roche lobe is neither necessary as a source of mass nor probable in view of the observed stellar line widths of the two identified X-ray companions. While not excluding the possibility that tidal forces may drive some mass outflow, a number of models are investigated in which the material to be accreted appears in the form of a stellar wind. The behavior of the accreted gas near the accreting object is discussed, as well as the transfer of angular momentum near the accreting object. It is concluded that a relatively simple stellar wind driven accretion model appears to satisfactorily account, in a quantitative but not precise way, for most of the observed features of Cen X-3.

Ostriker, J. P.↗
NASA NTRS1987

Cloud fluid models of gas dynamics and star formation in galaxies

The large dynamic range of star formation in galaxies, and the apparently complex environmental influences involved in triggering or suppressing star formation, challenges the understanding. The key to this understanding may be the detailed study of simple physical models for the dominant nonlinear interactions in interstellar cloud systems. One such model is described, a generalized Oort model cloud fluid, and two simple applications of it are explored. The first of these is the relaxation of an isolated volume of cloud fluid following a disturbance. Though very idealized, this closed box study suggests a physical mechanism for starbursts, which is based on the approximate commensurability of massive cloud lifetimes and cloud collisional growth times. The second application is to the modeling of colliding ring galaxies. In this case, the driving processes operating on a dynamical timescale interact with the local cloud processes operating on the above timescale. The results is a variety of interesting nonequilibrium behaviors, including spatial variations of star formation that do not depend monotonically on gas density.

Struck-Marcell, Curtis↗
NASA NTRS1989

Thermal barrier coating life prediction model development, phase 1

The objective of this program was to establish a methodology to predict thermal barrier coating (TBC) life on gas turbine engine components. The approach involved experimental life measurement coupled with analytical modeling of relevant degradation modes. Evaluation of experimental and flight service components indicate the predominant failure mode to be thermomechanical spallation of the ceramic coating layer resulting from propagation of a dominant near interface crack. Examination of fractionally exposed specimens indicated that dominant crack formation results from progressive structural damage in the form of subcritical microcrack link-up. Tests conducted to isolate important life drivers have shown MCrAlY oxidation to significantly affect the rate of damage accumulation. Mechanical property testing has shown the plasma deposited ceramic to exhibit a non-linear stress-strain response, creep and fatigue. The fatigue based life prediction model developed accounts for the unusual ceramic behavior and also incorporates an experimentally determined oxide rate model. The model predicts the growth of this oxide scale to influence the intensity of the mechanic driving force, resulting from cyclic strains and stresses caused by thermally induced and externally imposed mechanical loads.

Demasi, Jeanine T.↗
NASA NTRS2001

Updated Electronic Testbed System

As we continue to advance in exploring space frontiers, technology must also advance. The need for faster data recovery and data processing is crucial. In this, the less equipment used, and lighter that equipment is, the better. Because integrated circuits become more sensitive in high altitude, experimental verification and quantification is required. The Center for Applied Radiation Research (CARR) at Prairie View A&M University was awarded a grant by NASA to participate in the NASA ER-2 Flight Program, the APEX balloon flight program, and the Student Launch Program. These programs are to test anomalous errors in integrated circuits due to single event effects (SEE). CARR had already begun experiments characterizing the SEE behavior of high speed and high density SRAM's. The research center built a error testing system using a PC-104 computer unit, an Iomega Zip drive for storage, a test board with the components under test, and a latchup detection and reset unit. A test program was written to continuously monitor a stored data pattern in the SRAM chip and record errors. The devices under test were eight 4Mbit memory chips totaling 4Mbytes of memory. CARR was successful at obtaining data using the Electronic TestBed System (EBS) in various NASA ER-2 test flights. These series of high altitude flights of up to 70,000 feet, were effective at yielding the conditions which single event effects usually occur. However, the data received from the series of flights indicated one error per twenty-four hours. Because flight test time is very expensive, the initial design proved not to be cost effective. The need for orders of magnitude with more memory became essential. Therefore, a project which could test more memory within a given time was created. The goal of this project was not only to test more memory within a given time, but also to have a system with a faster processing speed, and which used less peripherals. This paper will describe procedures used to build an updated Electronic Testbed System.

Brewer, Kevin L.↗
NASA NTRS1995

Observations of chemical processing in the circumstellar environment

High resolution interferometer and single-dish observations of young, deeply embedded stellar systems reveal a complex chemistry in the circumstellar environments of low to intermediate mass stars. Depletions of gas-phase molecules, grain mantle evaporation, and shock interactions actively drive chemical processes in different regions around young stars. We present results for two systems, IRAS 05338-0624 and NCG 1333 IRAS 4, to illustrate the behavior found and to examine the physical processes at work.

NASA Program Exobiology↗
NASA NTRS1987

Teaching artificial neural systems to drive: Manual training techniques for autonomous systems

A methodology was developed for manually training autonomous control systems based on artificial neural systems (ANS). In applications where the rule set governing an expert's decisions is difficult to formulate, ANS can be used to extract rules by associating the information an expert receives with the actions taken. Properly constructed networks imitate rules of behavior that permits them to function autonomously when they are trained on the spanning set of possible situations. This training can be provided manually, either under the direct supervision of a system trainer, or indirectly using a background mode where the networks assimilates training data as the expert performs its day-to-day tasks. To demonstrate these methods, an ANS network was trained to drive a vehicle through simulated freeway traffic.

Shepanski, J. F.↗
DOE OSTI2026

1994 Portland Household Travel Survey

The Portland Household Travel Survey was conducted under the auspices of the Oregon Department of Transportation to provide information suitable for gaining an in-depth understanding of the activity and travel behavior of both households in metropolitan areas and the individuals within those households. The first round of surveys collected household activity data from the four metropolitan planning organization areas around Portland, plus three extra counties (Marion, Polk, and Yamhill). A total of 11,762 households participated in this study. Each household member was asked to record any activity that lasted 30 minutes or longer, or any activity that required travel for the specified 48-hour period.

1Hz data↗
DOE OSTI2026

2003 Yakima County Household Travel Survey

The Yakima County Household Travel Survey was sponsored by the Yakima County Department of Public Works in Yakima, Washington, and it was conducted over a six-month period from December 2002 through June 2003. The study is an essential element in the transportation planning and modeling efforts for Yakima County. The purpose of the survey was to gather data on the socioeconomic characteristics and travel behavior of county residents, including household characteristics, person characteristics, vehicle characteristics, and travel-activity patterns. A total of 1,503 households were recruited to participate in the study, 1,107 of which provided travel data for all household members age 16 and older. Unweighted, the 1,107 households represent 3,084 persons (of which 2,221 were age 16 and older), had 2,138 vehicles available to them, and recorded a total of 7,369 trips.

1Hz data↗