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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Genome sequence of the thermophilic fresh-water bacterium Spirochaeta caldaria type strain (H1 T ), reclassification of Spirochaeta caldaria, Spirochaeta stenostrepta , and Spirochaeta zuelzerae in the genus Treponema as Treponema caldaria comb. nov., Treponema stenostrepta comb. nov., and Treponema zuelzerae comb. nov., and emendation of the genus Treponema

Spirochaeta caldaria Pohlschroeder et al. 1995 is an obligately anaerobic, spiral-shaped bacterium that is motile via periplasmic flagella. The type strain, H1 T , was isolated in 1990 from cyanobacterial mat samples collected at a freshwater hot spring in Oregon, USA, and is of interest because it enhances the degradation of cellulose when grown in co-culture with Clostridium thermocellum. Here we provide a taxonomic re-evaluation for S. caldaria based on phylogenetic analyses of 16S rRNA sequences and whole genomes, and propose the reclassification of S. caldaria and two other Spirochaeta species as members of the emended genus Treponema. Whereas genera such as Borrelia and Sphaerochaeta possess well-distinguished genomic features related to their divergent lifestyles, the physiological and functional genomic characteristics of Spirochaeta and Treponema appear to be intermixed and are of little taxonomic value. The 3,239,340 bp long genome of strain H1 T with its 2,869 protein-coding and 59 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2011

The Role of Low-Angle Extensional Tectonics, Flat Fracture Domains, and Gravity Slides in Hydrothermal and EGS Resources of the Western United States

The Steamboat Springs geothermal system provides the most dramatic example of subhorizontal thermal-fluid aquifers in crystalline rock in the Basin and Range, but this is by no means an isolated case. Similar but more diffuse subhorizontal permeability has been reported at Roosevelt Hot Springs and Cove-Fort Sulphurdale, Utah; and a km-scale gravity-slide block channels injectate at Dixie Valley, Nevada. During the course of this phase of the project 2543 reports including text, figures and large format enclosures, 1428 maps, and 698 well logs were scanned. The information is stored in a Microsoft Access Database on the Geothermal Server. Detailed geologic cross sections of the Desert Peak geothermal field were developed to identify the structural controls on the geothermal system and locate possible fluid flow paths. The results of this work were published by Lutz and others (2009, Appendix 1) in the Stanford Reservoir Engineering Conference Proceedings.

02 PETROLEUM↗
DOE OSTI2018

Using tracer-derived groundwater transit times to assess storage within a high-elevation watershed of the upper Colorado River Basin, USA

Previous watershed assessments have relied on annual baseflow to evaluate the groundwater contribution to streams. To quantify the volume of groundwater in storage, additional information such as groundwater mean transit time (MTT) is needed. This study determined the groundwater MTT in the West Fork Duchesne watershed in Utah (USA) with lumped-parameter modeling of environmental tracers (SF{sub 6}, CFCs, and {sup 3}H/{sup 3}He) from 21 springs. Approximately 30% of the springs exhibited an exponential transit time distribution (TTD); the remaining ~70% were best characterized by a piston-flow TTD. The flow-weighted groundwater MTT for the West Fork watershed is about 40 years with approximately 20 years in the unsaturated zone. A cumulative distribution of these ages revealed that most of the groundwater is between 30 and 50 years old, suggesting that declining recharge associated with 5–10-year droughts is less likely to have a profound effect on this watershed compared with systems with shorter MTTs. The estimated annual baseflow of West Fork stream flow based on chemical hydrograph separation is ~1.7 × 10{sup 7} m{sup 3}/year, a proxy for groundwater discharge. Using both MTT and groundwater discharge, the volume of mobile groundwater stored in the watershed was calculated to be ~6.5 × 10{sup 8} m{sup 3}, or ~20 m thickness of active groundwater storage and recharge of ~0.09 m/year (assuming porosity = 15%). Future watershed-scale assessments should evaluate groundwater MTT, in addition to annual baseflow, to quantify groundwater storage and more accurately assess watershed susceptibility to drought, groundwater extraction, and land-use change.

58 GEOSCIENCES↗
DOE OSTI2018

Water-table and discharge changes associated with the 2016–2017 seismic sequence in central Italy: hydrogeological data and a conceptual model for fractured carbonate aquifers

A seismic sequence in central Italy from August 2016 to January 2017 affected groundwater dynamics in fractured carbonate aquifers. Changes in spring discharge, water-table position, and streamflow were recorded for several months following nine Mw 5.0–6.5 seismic events. Data from 22 measurement sites, located within 100 km of the epicentral zones, were analyzed. The intensity of the induced changes were correlated with seismic magnitude and distance to epicenters. The additional post-seismic discharge from rivers and springs was found to be higher than 9 m{sup 3}/s, totaling more than 0.1 km{sup 3} of groundwater release over 6 months. This huge and unexpected contribution increased streamflow in narrow mountainous valleys to previously unmeasured peak values. Analogously to the L’Aquila 2009 post-earthquake phenomenon, these hydrogeological changes might reflect an increase of bulk hydraulic conductivity at the aquifer scale, which would increase hydraulic heads in the discharge zones and lower them in some recharge areas. The observed changes may also be partly due to other mechanisms, such as shaking and/or squeezing effects related to intense subsidence in the core of the affected area, where effects had maximum extent, or breaching of hydraulic barriers.

58 GEOSCIENCES↗
DOE OSTI2019

Effect of Preheated Microstructure Vis-à-vis Process Parameters and Characterization of Orange Peel in Incremental Forming of AA1050 Sheets

The present investigation systematically analyzes and compares the influence of microstructure and crystallographic texture of AA1050 sheet to that of the most critical process parameters, namely tool dimension, and incremental step depth, in single-point incremental forming (SPIF) process. The sheet samples were preheated at different temperatures to reform the original, i.e., distorted and misoriented grain distribution. The results from experimental and statistical analyses report higher sensitivity of global spring back, surface topography and forming limits strains to variations in microstructure and texture than tool diameter and incremental step depth. The preheating of the sheets resulted in the formation of preferential texture by grain reformation, which leads to the increase in the fraction of homogeneous orientated grains. Such grains increase the maximum forming limit strains and reduce the global spring back in SPIF. Fractography analysis of the failed components revealed that improvement in formability due to grain homogenization (developed texture) may be attributed to larger average void diameter. Empirical models were also developed, and optimized levels of parameters were identified to maximize the efficiency of the SPIF process. Further, qualitative and quantitative characterization of orange peel roughness was carried out by segregating the external formed surface into surfaces subjected to orange peel roughness and tool-induced texture.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Photoproduction of K{Sigma}(1385) from the nucleon

The reactions of K{Sigma}(1385) photoproduction, i.e., {gamma}p {yields} K{sup +}{Sigma}{sup 0}(1385) and {gamma} {yields} K{sup +}{Sigma}{sup -}(1385), are investigated in the resonance energy region for studying the role of the nucleon and {Delta} resonances of masses around 2 GeV. The Lagrangians for describing the decays of these resonances into the K{Sigma}(1385) channel are constructed and the decay amplitudes are obtained, which allows us to determine the coupling constants using the predictions of quark models or the data listed by the Particle Data Group. The resulting cross sections are compared to the data from the Thomas Jefferson National Accelerator Facility and the SPring-8, which indicates nontrivial contributions from the two-star-rated resonances in the Particle Data Group as well as from some missing resonances predicted by a quark model.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

A miniaturized piezoelectric turbine with self-regulation for increased air speed range

This paper presents the design and demonstration of a piezoelectric turbine with self-regulation for increased air speed range. The turbine's transduction is achieved by magnetic “plucking” of a piezoelectric beam by the passing rotor. The increased speed range is achieved by the self-regulating mechanism which can dynamically adjust the magnetic coupling between the magnets on the turbine rotor and the piezoelectric beam using a micro-spring. The spring is controlled passively by the centrifugal force of the magnet on the rotor. This mechanism automatically changes the relative position of the magnets at different rotational speeds, making the coupling weak at low airflow speeds and strong at high speeds. Hence, the device can start up with a low airflow speed, and the output power can be ensured when the airflow speed is high. A theoretical model was established to analyse the turbine's performance, advantages, and to optimize its design parameters. A prototype was fabricated and tested in a wind tunnel. The start-up airflow speed was 2.34 m/s, showing a 30% improvement against a harvester without the mechanism.

42 ENGINEERING↗
DOE OSTI2025

Descriptor: Infrastructure Perception and Control: Multi-Sensor Object Tracking Dataset (IPC-MSOT)

Traffic intersections are crucial and challenging nodes in transportation networks where multiple lanes of vehicles and pedestrians converge. Traffic accidents often occur at traffic intersections, including a large proportion of traffic fatalities and about one-half of all traffic injuries in the United States. Object detection data were collected in 2024 across three intersections in Colorado Springs, CO, USA, over the course of multiple days and various times to induce a heterogeneous mix of traffic conditions and behaviors. The purpose of the data collection exercises was to learn various attributes about infrastructure sensors and to build a repository of high-resolution, object-level data that can be used for research and development (e.g., to develop multisensor data fusion algorithms). The Infrastructure Perception and Control:Multi-Sensor Object tracking (IPC-MSOT) dataset was collected as part of the U.S. Department of Transportation's Strengthening Mobility and Revolutionizing Transportation (SMART) project, where the city of Colorado Springs, Colorado, and the National Renewable Energy Laboratory collaborated to collect object-level trajectory data from road users using multiple types of infrastructure sensors deployed at different intersections. This dataset allows for testing of late-stage sensor fusion algorithms and their ability to ingest multimodal sensor data, and it can be utilized by traffic engineers to design and evaluate trajectory-based signal control strategies.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2013

Climate Change Impacts on Streamflow and Subbasin-Scale Hydrology in the Upper Colorado River Basin

In the Upper Colorado River Basin (UCRB), the principal source of water in the southwestern U.S., demand exceeds supply in most years, and will likely continue to rise. While General Circulation Models (GCMs) project surface temperature warming by 3.5 to 5.6°C for the area, precipitation projections are variable, with no wetter or drier consensus. We assess the impacts of projected 21 st century climatic changes on subbasins in the UCRB using the Soil and Water Assessment Tool, for all hydrologic components (snowmelt, evapotranspiration, surface runoff, subsurface runoff, and streamflow), and for 16 GCMs under the A2 emission scenario. Over the GCM ensemble, our simulations project median Spring streamflow declines of 36% by the end of the 21 st century, with increases more likely at higher elevations, and an overall range of -100 to +68%. Additionally, our results indicated Summer streamflow declines with median decreases of 46%, and an overall range of -100 to +22%. Analysis of hydrologic components indicates large spatial and temporal changes throughout the UCRB, with large snowmelt declines and temporal shifts in most hydrologic components. Warmer temperatures increase average annual evapotranspiration by ~ 23%, with shifting seasonal soil moisture availability driving these increases in late Winter and early Spring. For the high-elevation water-generating regions, modest precipitation decreases result in an even greater water yield decrease with less available snowmelt. Precipitation increases with modest warming do not translate into the same magnitude of water-yield increases due to slight decreases in snowmelt and increases in evapotranspiration. For these basins, whether modest warming is associated with precipitation decreases or increases, continued rising temperatures may make drier futures. Subsequently, many subbasins are projected to turn from semi-arid to arid conditions by the 2080 s. In conclusion, water availability in the UCRB could significantly decline with adverse consequences for water supplies, agriculture, and ecosystem health.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Nevada Great Basin Play Fairway Analysis Regional Data

This project focused on defining geothermal play fairways and development of a detailed geothermal potential map of a large transect across the Great Basin region (96,000 km2), with the primary objective of facilitating discovery of commercial-grade, blind geothermal fields (i.e. systems with no surface hot springs or fumaroles) and thereby accelerating geothermal development in this promising region. Data included in this submission consists of: structural settings (target areas, recency of faulting, slip and dilation potential, slip rates, quality), regional-scale strain rates, earthquake density and magnitude, gravity data, temperature at 3 km depth, permeability models, favorability models, degree of exploration and exploration opportunities, data from springs and wells, transmission lines and wilderness areas, and published maps and theses for the Nevada Play Fairway area.

130C↗
DOE OSTI2021

Brady Geodatabase for Geothermal Exploration Artificial Intelligence

These files contain the geodatabases related to Brady's Geothermal Field. It includes all input and output files for the Geothermal Exploration Artificial Intelligence. Input and output files are sorted into three categories: raw data, pre-processed data, and analysis (post-processed data). In each of these categories there are six additional types of raster catalogs which are titled Radar, SWIR, Thermal, Geophysics, Geology, and Wells. These inputs and outputs were used with the Geothermal Exploration Artificial Intelligence to identify indicators of blind geothermal systems at the Brady Hot Springs Geothermal Site. The included zip file is a geodatabase to be used with ArcGIS and the tar file is an inclusive database that encompasses the inputs and outputs for the Brady Hot Springs Geothermal Site.

15 GEOTHERMAL ENERGY↗
DOE OSTI2022

INGENIOUS - Great Basin Regional Dataset Compilation

This is the regional dataset compilation for the INnovative Geothermal Exploration through Novel Investigations Of Undiscovered Systems (INGENIOUS) project. The primary goal of this project is to accelerate discoveries of new, commercially viable hidden geothermal systems while reducing the exploration and development risks for all geothermal resources. These datasets will be used in INGENIOUS as input features for predicting geothermal favorability throughout the Great Basin study area. Datasets consist of shapefiles, geotiffs, tabular spreadsheets, and metadata that describe: 2-meter temperature probe surveys, quaternary faults and volcanic features, geodetic shear and dilation models, heat flow, magnetotellurics (conductance), magnetics, gravity, paleogeothermal features (such as sinter and tufa deposits), seismicity, spring and well temperatures, spring and well aqueous geochemistry analyses, thermal conductivity, and fault slip and dilation tendency. For additional project information, see the INGENIOUS project site linked in the submission. Terms of use: These datasets are provided "as is", and the contributors assume no responsibility for any errors or omissions. The user assumes the entire risk associated with their use of these data and bears all responsibility in determining whether these data are fit for their intended use. These datasets may be redistributed with attribution (see citation information below). Please refer to the license information on this page for full licensing terms and conditions.

15 GEOTHERMAL ENERGY↗
DOE OSTI2025

Geochemistry and Strontium Isotopes for Coal Creek Watershed, Colorado, 2021-2022

The geochemistry and strontium isotope data for Coal Creek Watershed, Colorado, consists of cation, anion, and 87Sr/87Sr isotope values from samples collected at 8 stream location along Coal Creek, samples from two groundwater springs within the watershed, and a shallow subsurface piezometer. All stream and spring samples were collected between June and October, 2021, and the shallow, near stream piezometer sample was collected in July of 2022. These data were collected to evaluate how groundwater contributions to Coal Creek originating from shallow vs deep flow paths respond seasonal drying. Understanding of groundwater-surface water interactions in montane systems in critical for the future of water availability in the Western US as groundwater contributions are expected to become more important for sustaining summer stream flows. This data package contains: (1) a csv of all cation samples; (2) a csv of all anion samples; (3) a csv of all 87Sr/87Sr isotope samples; and (4) a csv of locations for each sampling site. The dataset additionally includes a file-level metadata (flmd.csv) file that lists each file contained in the dataset with associated metadata; and a data dictionary (dd.csv) file that contains column/row headers used throughout the files along with a definition, units, and data type.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Mining Thermophile Photosynthesis Genes: A Synthetic Operon Expressing Chloroflexota Species Reaction Center Genes in Rhodobacter sphaeroides

Photosynthesis is the foundation of the vast majority of life systems, and is therefore the most important bioenergetic process on earth. The greatest diversity of photosynthetic systems is found in microorganisms. However, our understanding of the biophysical and biochemical processes that transduce light into chemical energy is derived from a relatively small subset of proteins from microbes that are amenable to cultivation, in contrast to the huge number of predicted proteins that catalyze the initial photochemical reactions deposited in databases, such as from metagenomics. We describe the use of a Rhodobacter sphaeroides laboratory strain for the expression of heterologous photosynthesis genes to demonstrate the feasibility of mining this resource, focusing on hot spring Chloroflexota gene sequences. Using a synthetic operon of genes, we produced a photochemically active complex of reaction center proteins in our biological system. We also present bioinformatic analyses of anoxygenic type II reaction center sequences from metagenomic samples collected from hot (42–90 °C) springs available through the JGI IMG database, to generate a resource of diverse sequences that are potentially adapted to photosynthesis at such temperatures. These data provide a view into the natural diversity of anoxygenic photosynthesis, through a lens focused on high-temperature environments. The approach we took to express such genes can be applied for potential biotechnology purposes as well as for studies of fundamental catalytic properties of these heretofore inaccessible protein complexes.

Chloroflexota↗
DOE OSTI2020

Hydrokinetic Power Conversion Using Vortex-Induced Oscillation with Cubic Restoring Force

A cubic-spring restoring function with high-deformation stiffening is introduced to passively improve the harnessed marine hydrokinetic power by using flow-induced oscillations/vibrations (FIO/V) of a cylinder. In these FIO/V experiments, a smooth, rigid, single-cylinder on elastic end-supports is tested at Reynolds numbers ranging from 24,000 < Re < 120,000. The parameters of the tested current energy converter (CEC) are cubic stiffness and linear damping. Using the second generation of digital virtual spring-damping (Vck) controller developed by the Marine Renewable Energy Laboratory (MRELab), the cubic modeling of the oscillator stiffness is tested. Experimental results show the influence of the parameter variation on the amplitude, frequency, energy conversion, energy efficiency, and power of the converter. All experiments are conducted in the low turbulence-free surface water (LTFSW) channel of the MRELab of the University of Michigan. The main conclusions are: (1) The nonlinearity in the cubic oscillator is an effective way to extend the vortex-induced vibration (VIV) upper branch, which results in higher harnessing power and efficiency compared to the linear stiffness cylinder converter. (2) Compared to the linear converter, the overall power increase is substantial. The nonlinear power optimum, occurring at the end of the VIV upper branch, is 63% higher than its linear counterpart. (3) The cubic stiffness converter with low harnessing damping achieves consistently good performance in all the VIV regions because of the hardening restoring force, especially at higher flow velocity.

13 HYDRO ENERGY↗
DOE OSTI2018

Provisional Conceptual Model of the Camas Prairie (ID) Geothermal System from Play Fairway Analysis

Camas Prairie, Idaho, is an EW-trending structural graben that lies north of the Snake River Plain hotspot track. It is bounded on the north by the Idaho Batholith, and on the south by the Mount Bennett Hills. This region was investigated by the SRP Geothermal Play Fairway Analysis team, which included focused geologic, geochemical, and geophysical studies. The Camas Prairie geothermal system resource is indicated by warm springs and wells, geophysical analysis of buried faults and basins, mapped faults, structural analysis of all faults and lineaments, high 3He/4He, cation and multicomponent geothermometry, and the occurrence of young basalt vents and lava flows along the range front. Our provisional conceptual model includes the following components: (1) High permeability is indicated by the confluence of intersecting faults, including the major range front system and The Pothole fault system, with releasing bends as deduced from detailed field studies, and the presence of springs along mapped structural features; (2) High heat is inferred to result from mid- to shallow crustal sills, as evidenced by the location of vents along the range front; the youngest dated vent is 692 ka, but 2 ka vents lie to NW; (3) an effective seal is indicated by magnetotelluric studies, which suggest a clay seal over the prospective target area that is likely a result of hydrothermal alteration. This model is similar to that proposed for the western SRP but is less energetic due to the smaller volume of magma inferred. It is also similar to Basin-and-Range geothermal systems, but differs by including a distinct magmatic heat component.

15 GEOTHERMAL ENERGY↗
DOE OSTI2014

Observed Holiday Aerosol Reduction and Temperature Cooling over East Asia

The Spring Festival air pollution in China was investigated using the long-term observations from 2001-2012 over 323 stations. During the Spring Festival with nearly half of urban population leaving the cities for holidays, the particulate matter (PM10) concentration is about 24.5μgm-3 (23%) lower than normal days. Associated with the national-wide burning of firework, the PM10 concentration sharply increases to 123.8μgm-3 at Chinese New Year Day (increment of 35%). Similar to PM10, the SO2 and NO2 decrease from high values in normal days to a holiday minimum with reduction of 23.3% and 30.6%, respectively. The NO2 has no peak in New Year Day because of the different emission source. The night mean and minimum temperature co-vary with PM10. Both nighttime mean and minimum temperature decrease by about 2.1°C during the holidays. And in association with the pollution jump at New Year Day the night temperature simultaneously increase by about 0.89°C. The in-phase co-variations between PM10 and night temperature suggest an overall warming effect of holiday aerosol during winter in China.

Gong, Daoyi↗
DOE OSTI2017

The diurnal cycle of clouds and precipitation at the ARM SGP site: Cloud radar observations and simulations from the multiscale modeling framework

Millimeter Wavelength Cloud Radar (MMCR) data from December 1996 to December 2010, collected at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program Southern Great Plains (SGP) site, are used to examine the diurnal cycle of hydrometeor occurrence. These data are categorized into clouds (-40 dBZ e ≤ reflectivity < -10 dBZ e ), drizzle and light precipitation (-10 dBZ e ≤ reflectivity < 10 dBZ e ), and heavy precipitation (reflectivity ≥ 10 dBZ e ). The same criteria are implemented for the observation-equivalent reflectivity calculated by feeding outputs from a Multiscale Modeling Framework (MMF) climate model into a radar simulator. The MMF model consists of the National Center for Atmospheric Research Community Atmosphere Model with conventional cloud parameterizations replaced by a cloud-resolving model. We find that a radar simulator combined with the simple reflectivity categories can be an effective approach for evaluating diurnal variations in model hydrometeor occurrence. It is shown that the MMF only marginally captures observed increases in the occurrence of boundary layer clouds after sunrise in spring and autumn and does not capture diurnal changes in boundary layer clouds during the summer. Above the boundary layer, the MMF captures reasonably well diurnal variations in the vertical structure of clouds and light and heavy precipitation in the summer but not in the spring.

54 ENVIRONMENTAL SCIENCES↗