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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
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.

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DOE OSTI2026

2005 Tahoe Regional Household Travel Survey

The 2005 Tahoe Regional Household Travel Survey is a comprehensive survey of the travel patterns of households in the Tahoe Basin region of California and Nevada. The survey was conducted for the Tahoe Regional Planning Agency over a four-month period, from June through September 2005. This collection contains two sets of travel data: 1) a survey of 1,220 permanent households within the Tahoe Basin region and 2) a subset survey of 125 seasonal households within the same area. The permanent resident dataset contains information about 2,732 household members, 2,471 vehicles, and 11,048 trips made during a 24-hour period. The seasonal resident subset features 726 trip observations and information about 229 household members and 185 vehicles. The survey relied on the willingness of study area residents to 1) provide demographic information about their household, its members, and its vehicles and 2) document all travel for each household member, regardless of age, over an assigned 24-hour period. During the recruitment phase, respondents were asked to provide detailed household information, including permanent or seasonal resident status, number of household occupants, type of dwelling unit, number of vehicles available to household members, as well as the year, body type, and fuel type of each vehicle. Survey participants received mailed travel logs to aid in documenting travel information for the 24-hour assessment period. Respondents were instructed to record their mode of transportation, trip purpose, number of passengers, departure and arrival times, activities at each trip destination, ride fare, and parking costs. Demographic information for this study includes age, gender, income, education, and employment status.

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DOE OSTI2026

1994 Household Travel Survey

The Metropolitan Washington Council of Governments/National Capital Region Transportation Planning Board (COG/TPB) periodically conducts regional household travel surveys to monitor changes in daily travel and to gather information on the demographic, socioeconomic, and trip-making characteristics of Washington, D.C.-area residents. Information collected in the 1994 Household Travel Survey was an important component in the development of regional travel demand forecasting models used to predict changes in daily travel in response to current development trends and changes in regional transportation policies and programs. In two waves during the spring and fall of 1994, consultants for COG/TPB conducted a survey of daily travel by persons living in area households. The survey file contains travel information associated with 4,863 households residing in 13 jurisdictions comprising the greater Washington, D.C., region (approximately a 1-in-300 sample). The survey file contains 39,800 internal trip records with respect to the expanded cordon.

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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.

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DOE OSTI2026

1968 Metropolitan Washington Council of Governments/National Capital Region Transportation Planning Board Home Interview Survey

The Metropolitan Washington Council of Governments/National Capital Region Transportation Planning Board periodically conducts regional household travel surveys to monitor changes in daily travel and to gather information on the demographic, socioeconomic, and trip-making characteristics of Washington, D.C.-area residents. Information collected in the 1968 Home Interview Survey was an important component in the development of regional travel demand forecasting models used to predict changes in daily travel in response to current development trends and changes in regional transportation policies and programs. The survey sampled 26,000 households residing in six jurisdictions comprising the greater Washington, D.C. region (an approximately 1-in-20 sample).

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DOE OSTI2026

1987/88 Metropolitan Washington Council of Governments/National Capital Region Transportation Planning Board Home Interview Survey

The Metropolitan Washington Council of Governments/National Capital Region Transportation Planning Board periodically conducts regional household travel surveys to monitor changes in daily travel and to gather information on the demographic, socioeconomic, and trip-making characteristics of Washington, D.C.-area residents. Information collected in the 1987/88 Home Interview Survey was an important component in the development of regional travel demand forecasting models used to predict changes in daily travel in response to current development trends and changes in regional transportation policies and programs. The survey sampled 8,000 households residing in eight jurisdictions comprising the greater Washington, D.C. region (an approximately 1-in-166 sample).

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DOE OSTI2026

Atlanta—1991 Household Interview Survey

The Atlanta Regional Commission conducted a Household Travel Survey in 1991 to capture the reality of the locale, including infrastructure improvements—such as new highways, rail, and housing developments—additional households, income, trip chaining, and telecommuting, as well as other typical demographic characteristics. The survey collected demographic, socioeconomic, and travel information on work and non-work travel behavior. Travel data includes trip generation, trip distribution, and modal choice for 3,626 households that completed a travel log.

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DOE OSTI2026

1993 Baltimore Household Travel Survey

The 1993 Baltimore Household Travel Survey is a detailed survey of demographic characteristics and travel patterns for 2,692 households in Baltimore, Maryland. The original goal of the survey was to collect an “ideal” dataset for disaggregate travel demand analysis.

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DOE OSTI2026

1991 California Statewide Travel Survey

The California Statewide Travel Survey was conducted in 1991. Data were collected from 17,040 households throughout the state, with a minimum of 500 samples in any one region. The survey was primarily used to update trip generation rates.

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DOE OSTI2026

1998 Dallas-Fort Worth Travel Survey

The 1998 Dallas-Fort Worth House Travel Survey accomplished two main goals: updating existing data for the North Central Texas Council of Governments regional travel demand models and providing new data to permit the models to be upgraded. The survey encompassed households within the Consolidated Metropolitan Statistical Area of Dallas-Fort Worth. A total of 4,641 households provided complete information. The survey revealed households' travel behavior preference with the collection of information about household characteristics and travel using a unique "travel as an activity" approach.

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DOE OSTI2026

1999 Dallas-Fort Worth Travel Survey

The 1999 Dallas-Fort Worth House Travel Survey accomplished two main goals: updating the existing data for the North Central Texas Council of Governments regional travel demand models and providing new data to permit the models to be upgraded. The survey encompassed households within the Consolidated Metropolitan Statistical Area of Dallas-Fort Worth. A total of 4,641 households provided complete information. The survey revealed households' travel behavior preference with the collection of information about household characteristics and travel using a unique "travel as an activity" approach.

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DOE OSTI2026

2000 Evansville Household Travel Survey

The Evansville Metropolitan Planning Organization conducted a household travel survey in 2000. This study aimed to produce a detailed analysis of travel behavior for the residents of the Evansville Metropolitan Area. The survey contains data from 1,737 participating households. From participants' travel records, a total of 20,096 trips were reported by 4,069 people for a 24-hour period.

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DOE OSTI2026

1996 Tampa Bay Regional Travel Survey

This study was conducted on behalf of the Florida Department of Transportation. The purpose of the survey was to understand day-to-day travel across the Tampa Bay region. Demographic, socioeconomic, and travel data were gathered from 5,349 households that participated in the study, and a total of 31,465 trips were recorded.

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DOE OSTI2026

1993 Tucson Household Travel Survey

The Arizona Department of Transportation (ADOT) conducted a Tucson Household Travel Survey in 1993. ADOT conducts such surveys every five to seven years, providing an essential snapshot of transportation behaviors and trends by asking how members of a household get around on a single day. The answers helped state, local, and federal officials decide when, where, and how to invest limited transportation funding to improve roads, public transportation, sidewalks, bike paths, and more. Demographic, socioeconomic, and travel information was gathered from 4,564 participants associated with 1,913 households. Participants received travel logs to record where members of their household went on an assigned travel day.

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DOE OSTI2026

2000 Tucson Household Travel Survey

The Arizona Department of Transportation (ADOT) conducted a Tucson Household Travel Survey in 2000. ADOT conducts such surveys every five to seven years, providing an essential snapshot of transportation behaviors and trends by asking how members of a household get around on a single day. The answers helped state, local, and federal officials decide when, where, and how to invest limited transportation funding to improve roads, public transportation, sidewalks, bike paths, and more. Demographic, socioeconomic, and travel information was gathered from 4,882 participants associated with 2,076 households. Participants received travel logs to record where members of their household went on an assigned travel day.

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DOE OSTI2026

1970 Home Interview Survey

The 1970 Home Interview Survey was conducted by Twin Cities Metropolitan Council, Saint Paul. This database was used to develop mathematical models to predict future regional travel patterns, which were used to develop appropriate regional transportation policies, plans, and programs. The 1970 survey did not specifically include walking or bicycling as options in the travel diary; instead, these trips are included in a broad “other” category.

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DOE OSTI2022

Origin of nontopological soliton dark matter: solitosynthesis or phase transition

This work demonstrates that nontopological solitons with large global charges and masses, even above the Planck scale, can form in the early universe and dominate the dark matter abundance. In solitosynthesis, solitons prefer to grow as large as possible under equilibrium dynamics when an initial global charge asymmetry is present. Their abundance is set by when soliton formation via particle fusion freezes out, and their charges are set by the time it takes to accumulate free particles. This work improves the estimation of both quantities, and in particular shows that much larger-charged solitons form than previously thought. The results are estimated analytically and validated numerically by solving the coupled Boltzmann equations. Without solitosynthesis, phase transitions can still form solitons from particles left inside false-vacuum pockets and determine their present-day abundance and properties. Even with zero charge asymmetry, solitons formed in this way can have very large charges on account of statistical fluctuations in the numbers of (anti)particles inside each pocket.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2021

A Low-Temperature Structural Transition in Canfieldite, Ag 8 SnS 6 , Single Crystals

Canfieldite, Ag 8 SnS 6 , is a semiconducting mineral notable for its high ionic conductivity, photosensitivity, and low thermal conductivity. In this paper, we report the solution growth of large single crystals of Ag 8 SnS 6 of mass up to 1 g from a ternary Ag–Sn–S melt. On cooling from high temperature, Ag 8 SnS 6 undergoes a known cubic ($F\bar{4}3m$) to orthorhombic ($Pna2_1$) phase transition at ≈460 K. By studying the magnetization and thermal expansion between 5–300 K, we discover a second structural transition at ≈120 K. Single crystal X-ray diffraction reveals the low-temperature phase adopts a different orthorhombic structure with space group $Pmn2_1$ ($\textit{a}$ = 7.662 9(5) Å, $\textit{b}$ = 7.539 6(5) Å, $\textit{c}$ = 10.630 0(5) Å, Z = 2 at 90 K) that is isostructural to the room-temperature forms of the related Se-based compounds Ag 8 SnSe 6 and Ag 8 GeSe 6 . The 120 K transition is first-order and has a large thermal hysteresis. On the basis of the magnetization and thermal expansion data, the room-temperature polymorph can be kinetically arrested into a metastable state by rapidly cooling to temperatures below 40 K. We last compare the room- and low-temperature forms of Ag8SnS6 with its argyrodite analogues, Ag 8 TQ 6 ($\textit{T}$ = Si, Ge, Sn; $\textit{Q}$ = S, Se), and identify a trend relating the preferred structures to the unit cell volume, suggesting smaller phase volume favors the $Pna2_1$ arrangement. We support this picture by showing that the transition to the $Pmn2_1$ phase is avoided in Ge alloyed Ag 8 Sn 1–x Ge x S 6 samples as well as in pure Ag 8 GeS 6 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗