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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 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Microbial diversity and carbon cycling in San Francisco Bay wetlands

Wetland restoration efforts in San Francisco Bay aim to rebuild habitat for endangered species and provide an effective carbon storage solution, reversing land subsidence caused by a century of industrial and agricultural development. However, the benefits of carbon sequestration may be negated by increased methane production in newly constructed wetlands, making these wetlands net greenhouse gas (GHG) sources to the atmosphere. We investigated the effects of wetland restoration on below-ground microbial communities responsible for GHG cycling in a suite of historic and restored wetlands in SF Bay. Using DNA and RNA sequencing, coupled with real-time GHG monitoring, we profiled the diversity and metabolic potential of wetland soil microbial communities. The wetland soils harbor diverse communities of bacteria and archaea whose membership varies with sampling location, proximity to plant roots and sampling depth. Our results also highlight the dramatic differences in GHG production between historic and restored wetlands and allow us to link microbial community composition and GHG cycling with key environmental variables including salinity, soil carbon and plant species.

09 BIOMASS FUELS↗
DOE OSTI2017

Building America Case Study: Occupant Comfort from a Mini-Split Heat Pump, San Antonio, Texas

IBACOS worked with builder Imagine Homes to evaluate the performance of an occupied new construction test house following construction of the house in the hot, humid climate of San Antonio, Texas. The project measures the effectiveness of a space conditioning strategy using a multihead mini-split heat pump (MSHP) system in a reduced-load home to achieve acceptable comfort levels (temperature and humidity) and energy performance. IBACOS collected long-term data and analyzed the energy consumption and comfort conditions of the occupied house after one year of operation. Although measured results indicate that the test system provides comfort both inside and outside the ASHRAE Standard 55-2010 range, the occupants of the house claimed both adequate comfort and appreciation of the ease of use and flexibility of the installed MSHP system. IBACOS also assisted the builder to evaluate design and specification changes necessary to comply with Zero Energy Ready Home, but the builder chose to not move forward with it because of concerns about the 'solar ready' requirements of the program.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2018

NREL and San Diego Gas & Electric Company

San Diego Gas & Electric Company (SDG&EA(R)) and NREL are collaborating to evaluate advanced metering infrastructure (AMI)-based controls for grid operations. With millions of new smart meters being deployed around the country, this collaboration will take the lead in determining how to generate insights from the AMI data, and to use these insights for real-time operations. Smart meters ensure availability of pervasive and continuous data from the grid-edge, a service that is not possible with traditional grid sensors.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

Quantifying Movement Motivations, Demand, and Inflow-Outflow Dynamics in Four Cities (New York, Chicago, Austin, and San Diego) During COVID-19: Preprint

COVID-19 has impacted human activities ranging from food delivery habits to major moving and travel decisions. It’s clear that multiple pandemic-related factors have influenced millions of relocation decisions by Americans (e.g. health risk, financial pressures, more space, employment). There are positive economic and social outcomes of this influence (e.g. remote work and education) enabling more affordable living and opportunity. This paper addresses COVID-19 impacts on mobility, especially the mobility that involves permanent relocation from place to place. Survey design and data analysis with U-Haul targeted customers in Austin, New York, San Diego, and Chicago to understand mobility, new moving dynamics, and motivations.

ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2024

Optimization of ray-tracing simulations to confirm performance of the GP-SANS instrument at the High-Flux Isotope Reactor

The CG-2 beamline at the High Flux Isotope Reactor (HFIR) exhibits a notable discrepancy between observed count rates and the count rates we would expect based on a Monte-Carlo neutron ray-trace simulation. These simulations consistently predict count rates approximately five times greater than those observed in four separate experimental runs involving different instrument configurations. This discrepancy suggests that certain factors are causing losses in measurements that are not adequately accounted for in the simulation, in particular guide reflectivity or misalignment. To investigate these discrepancies, a high-dimensional simulation parameter approach is applied in order to understand the losses. Region of Interest (ROI) groups along the instrument are assigned to different surfaces of the guide components within the simulation. This allows the parameters of those guide components to be varied as a group to minimize the complexity of the search space. The result is an optimization of simulation parameters using an iterative scheme that aims to minimize the difference between experimentally measured count rates and simulated count rates across all tested collimator combinations. This proposed methodology holds the potential to reveal previously unrecognized sources of intensity loss in the CG-2 beamline at HFIR and improve the accuracy of simulations, leading to enhanced understanding and performance of the beamline for various scientific applications.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2012

Geothermal Geodatabase for Rico Hot Springs Area and Lemon Hot Springs, Dolores and San Miguel Counties, Colorado

This geodatabase was built to cover several geothermal targets developed by Flint Geothermal in 2012 during a search for high-temperature systems that could be exploited for electric power development. Several of the thermal springs have geochemistry and geothermometry values indicative of high-temperature systems. In addition, the explorationists discovered a very young Climax-style molybdenum porphyry system northeast of Rico, and drilling intersected thermal waters at depth. Datasets include: 1. Structural data collected by Flint Geothermal 2. Point information 3. Mines and prospects from the USGS MRDS dataset 4. Results of reconnaissance shallow (2 meter) temperature surveys 5. Air photo lineaments 6. Areas covered by travertine 7. Groundwater geochemistry 8. Land ownership in the Rico area 9. Georeferenced geologic map of the Rico Quadrangle, by Pratt et al. 10. Various 1:24,000 scale topographic maps

15 GEOTHERMAL ENERGY↗
DOE OSTI2012

Surface Temperature Anomalies Derived from Night Time ASTER Data Corrected for Solar and Topographic Effects, San Miguel County, Colorado

This map shows areas of anomalous surface temperature in Alamosa and Saguache Counties identified from ASTER thermal data and spatial based insolation model. The temperature is calculated using the Emissivity Normalization Algorithm that separate temperature from emissivity. The incoming solar radiation was calculated using spatial based insolation model developed by Fu and Rich (1999). Then the temperature due to solar radiation was calculated using emissivity derived from ASTER data. The residual temperature, i.e. temperature due to solar radiation subtracted from ASTER temperature was used to identify thermally anomalous areas. Areas that had temperature greater than 2o were considered ASTER modeled "very warm modeled surface temperature" are shown in red on the map. Areas that had temperatures between 1o and 2o were considered ASTER modeled "warm modeled surface temperature" are shown in yellow on the map. This map also includes the locations of shallow temperature survey points, locations of springs or wells with favorable geochemistry, faults, transmission lines, and areas of modeled basement weakness "fairways." Note: 'o' is used in this description to represent lowercase sigma.

15 GEOTHERMAL ENERGY↗
DOE OSTI2022

Tidal Currents in San Juan Archipelago, Washington

Re-analyzed acoustic Doppler current profiler (ADCP) data originally collected by NOAA CO-OPS (Center for Operational Oceanographic Products and Services) and equivalent point data from Pacific Northwest National Laboratory's FVCOM (Finite Volume Community Ocean Model) model of the region. Data are processed to products describing characteristics of tidal currents relevant to tidal turbines, as well as power output estimates for a notional turbine deployed from a surface platform or from the seabed at each location. These data underpin the results presented in their associated paper - see below.

16 TIDAL AND WAVE POWER↗
DOE OSTI2019

The Effect of Fault Geometry and Minimum Shear Wavespeed on 3D Ground-Motion Simulations for an M w 6.5 Hayward Fault Scenario Earthquake, San Francisco Bay Area, Northern California

We investigated the effects of fault geometry and assumed minimum shear wavespeed (V Smin ) on 3D ground-motion simulations (0–2.5 Hz) in general, using a moment magnitude (M w ) 6.5 earthquake on the Hayward fault (HF). Simulations of large earthquakes on the northeast-dipping HF using the U.S. Geological Survey (USGS) 3D seismic model have shown intensity asymmetry with stronger shaking for the Great Valley Sequence east of the HF (hanging wall) relative to the Franciscan Complex to the west (footwall). We performed simulations with three fault geometries in both plane-layered (1D) and 3D models. Results show that the nonvertical fault geometries result in larger motions on the hanging wall relative to the vertical fault for the same Earth model with up to 50% amplifications in single-component peak ground velocity (PGV) within 10 km of the rupture. Near-fault motions on the footwall are reduced for the nonvertical faults, but less than they are increased on the hanging wall. Simulations assuming V Smin values of 500 and 250 m/s reveal that PGVs are on average 25% higher west of the HF when using the lower V Smin ,with some locations amplified by a factor of 3. Increasing frequency content from 2.5 to 5 Hz increases PGV values. Spectral ratios of these two V Smin cases show average amplifications of 2–4 (0.5–1.5 Hz) for the lower V Smin west of the fault. Large differences (up to 2×) in PGV across the HF from previous studies persist even for the case with a vertical fault or V Smin of 250 m/s. We conclude that assuming a V Smin of 500 m/s underestimates intensities west of the HF for frequencies above 0.5 Hz, and that low upper crustal (depth <10 km) shear wavespeeds defined in the 3D model contribute most to higher intensities east of the HF.

58 GEOSCIENCES↗
DOE OSTI2019

San Diego Tribal Energy Collaborative [Slides]

The project involves the installation and activation of 42 roof-top or ground mount solar photovoltaic systems. The system will use a combination of roof-top photovoltaic panels and ground-mounted panels that will be installed on 40 tribal homes and 2 tribal buildings throughout the three participating reservations. The scope of work includes site preparation, equipment installation, system testing, and inspection by a third-party inspector, system activation, troubleshooting, and final activation. It also includes any electrical system upgrades, which are anticipated to accommodate the new PV system. The system will displace at least 50% of the combined total of electricity needed by the participating structures. Implementing these systems will also provide hands-on solar installation training to at least 20 Tribal community volunteers and job trainees.

14 SOLAR ENERGY↗
NASA NTRS1993

Spectral Analysis of an AVIRIS Image of San Pedro Channel

Optical case-2 waters near an ocean outfall were examined, using a combination fo AVIRIS imagery and ship-based surface and profile bio-optical measurements. Bio-optical mooring data were useful in determining the hydrodynamics of the area.

San Pedro Channel Spectral Analysis↗