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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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Exploring the Use of FHWA Truck Traffic Volume and Weight Data to Support National Truck Freight Mobility Study
The goal of this exploratory study was to investigate alternative data sources and develop methodologies to estimate trends and adjustment factors that could be applied to calibrate statistics generated from the outdated 2002 VIUS. The main focus of this study was on utilizing the FHWA’s traffic data (i.e., VTRIS and TMAS), along with other supplemental freight data (i.e., FAF and CFS), to examine changes in truck volumes and truck weight distributions over time. Ultimately, this effort seeks to develop certain adjustments/factors that could be used to realign perspective VIUS data. Unfortunately, as pointed out previously in this technical memorandum, there are no readily available data sources that could be used to explicitly validate the estimated results from this study. This study compared the estimated distributions from the 2002 VTRIS to the 2002 VIUS data to establish linkages between the two datasets. With distributions and patterns generated based on VTRIS and TMAS data series for additional years, trend factors were then estimated and applied to “update” VIUS-based information. This study resulted in three key highlights: (1) Updated estimates on truck volume and truck VMT can be utilized to better estimate on energy uses by truck. (2) Vehicle class distribution, percent/share of empty trucks, and average truck payload could be updated by utilizing more current annual data series such as VTRIS and TMAS. (3) Additional information could be estimated (e.g., distance distribution by operational type) by integrating other data sources, such as CFS and FAF, instead of relying on the 2002 VIUS data.
Structure and properties of polyethylene films used in heavy lift balloons
The following features of five polyethylene films used by NASA in the construction of heavy lift balloons have been examined: molecular weight, molecular weight distribution, branching, melting behavior, density, surface texture, birefringence, orientation of crystalline regions, unlaxial deformation in the machine and transverse directions, and the effect of sample geometry and strain rate on deformation behavior. The goal of this exploratory study was to determine whether there are significant differences in any of the above mentioned features, or combination of features between the films. The acquisition of such information is a first step towards determining whether there are any specific correlations between film characteristics and the incidence of catastrophic failure of balloons during ascent through the troposphere. This exploratory study has resulted in the identification of similarities and differences between various features of the films.
A community-based evaluation of proximity to unconventional oil and gas wells, drinking water contaminants, and health symptoms in Ohio
Highlights: • We conducted a community-based study on unconventional oil and gas (UO&G) in Ohio. • We explored UO&G proximity in relation to water contamination and health symptoms. • Contaminant detection and concentrations decreased with greater distance to UO&G. • UO&G proximity was associated with increased general health symptoms (e.g. fatigue). • Communities near UO&G may be more likely to experience environmental health impacts. Over 4 million Americans live within 1.6 km of an unconventional oil and gas (UO&G) well, potentially placing them in the path of toxic releases. We evaluated relationships between residential proximity to UO&G wells and (1) water contamination and (2) health symptoms in an exploratory study. We analyzed drinking water samples from 66 Ohio households for 13 UO&G-related volatile organic compounds (VOCs) (e.g., benzene, disinfection byproducts [DBPs]), gasoline-range organics (GRO), and diesel-range organics. We interviewed participants about health symptoms and calculated metrics capturing proximity to UO&G wells. Based on multivariable logistic regression, odds of detection of bromoform and dibromochloromethane in surface water decreased significantly as distance to nearest UO&G well increased (odds ratios [OR]: 0.28–0.29 per km). Similarly, distance to nearest well was significantly negatively correlated with concentrations of GRO and toluene in ground water (r{sub Spearman}: −0.40 to −0.44) and with concentrations of bromoform and dibromochloromethane in surface water (r{sub Spearman}: −0.48 to −0.50). In our study population, those with higher inverse-distance-squared-weighted UO&G well counts within 5 km around the home were more likely to report experiencing general health symptoms (e.g. stress, fatigue) (OR: 1.52, 95%CI: 1.02–2.26). This exploratory study, though limited by small sample size and self-reported health symptoms, suggests that those in closer proximity to multiple UO&G wells may be more likely to experience environmental health impacts. Further, presence of brominated DBPs (linked to UO&G wastewater) raises the question of whether UO&G activities are impacting drinking water sources in the region. The findings from this study support expanded studies to advance knowledge of the potential for water quality and human health impacts; such studies could include a greater number of sampling sites, more detailed chemical analyses to examine source attribution, and objective health assessments.
Probing the plasma near high power wave launchers in fusion devices for static and dynamic electric fields (invited)
An exploratory study was carried out in the long-pulse tokamak Tore Supra, to determine if electric fields in the plasma around high-power, RF wave launchers could be measured with non-intrusive, passive, optical emission spectroscopy. The focus was in particular on the use of the external electric field Stark effect. The feasibility was found to be strongly dependent on the spatial extent of the electric fields and overlap between regions of strong (>∼1 kV/cm) electric fields and regions of plasma particle recycling and plasma-induced, spectral line emission. Most amenable to the measurement was the RF electric field in edge plasma, in front of a lower hybrid heating and current drive launcher. Electric field strengths and direction, derived from fitting the acquired spectra to a model including time-dependent Stark effect and the tokamak-range magnetic field Zeeman-effect, were found to be in good agreement with full-wave modeling of the observed launcher.
Exploratory characterization of a perfluoropolyether oil as a possible viscosity standard at deepwater production conditions of 533 K and 241 MPa
DuPont’s perfluoropolyether oil Krytox ® GPL 102 is a promising candidate for the high-temperature, high-pressure Deepwater viscosity standard (DVS). The preferred DVS is a thermally stable liquid that exhibits a viscosity of roughly 20 mPa ∙ s at 533 K and 241 MPa; a viscosity value representative of light oils found in ultra-deep formations beneath the deep waters of the Gulf of Mexico. Furthermore, a windowed rolling-ball viscometer designed by our team is used to determine the Krytox ® GPL 102 viscosity at pressures to 245 MPa and temperatures of 311 K, 372 K, and 533 K. At 533 K and 243 MPa, the Krytox ® GPL 102 viscosity is (27.2±1.3)mPa ∙ s. The rolling-ball viscometer viscosity results for Krytox ® GPL 102 are correlated with an empirical 10-parameter surface fitting function that yields an MAPD of 3.9 %. A Couette rheometer is also used to measure the Krytox ® GPL 102 viscosity, yielding a value of (26.2±1)mPa ∙ s at 533 K and 241 MPa. The results of our exploratory study suggest that Krytox ® GPL 102 is a promising candidate for the DVS, primarily because this fluoroether oil is thermally stable and exhibits a viscosity closer to the targeted value of 20 mPa ∙ s at 533 K and 241 MPa than any other fluid reported to date. Nonetheless, further studies must be conducted by other researcher groups using various types of viscometers and rheometers on samples of Krytox GPL ® 102 from the same lot to further establish the properties of Krytox GPL ® 102.
Dispersible Colloid Facilitated Release of Organic Carbon From Two Contrasting Riparian Sediments
In aqueous systems, including groundwater, nano-colloids (1–100 nm diameter) and small colloids (<450 nm diameter) provide a vast store of surfaces to which organic carbon (OC) can sorb, precluding its normal bioavailability. Because nanomaterials are ubiquitous and abundant throughout Earth systems, it is reasonable that they would play a significant role in biogeochemical cycles. As such, mineral nano-colloids (MNC) and small colloids, formed through mineral weathering and precipitation processes, are both an unaccounted-for reservoir and unquantified vector for transport of OC and nutrients and contaminants within watersheds. Water extractions and leaching experiments were conducted under (1) aerobic (ambient) and (2) anaerobic (environmental chamber) conditions for each of two contrasting riparian sediments from (1) Columbia River, Washington and (2) Tims Branch, South Carolina. Water dispersible colloid-adsorbed OC was as high as 48% of OC for Tims Branch anaerobic batch water extraction and as low as 0% for Columbia River aerobic batch water extractions. Anaerobic leaching from column experiments yielded higher colloid and OC release rates. Transmission electron microscopy with electron dispersive spectroscopy mapping revealed organic carbon associated with aggregations of nano-particulate silicate minerals and Mossbauer identified nano-particulate goethite. This exploratory study demonstrates that mineral facilitated release of OC in riparian sediments is both significant and variable between locations.
Modeling sediment diagenesis processes on riverbed to better quantify aquatic carbon fluxes and stocks in a small watershed of the Mid-Atlantic region
Background: Despite the widely recognized importance of aquatic processes for bridging gaps in the global carbon cycle, there is still a lack of understanding of the role of riverbed processes for carbon flows and stocks in aquatic environments. Here, we added a sediment diagenesis and sediment carbon (C) resuspension module into the SWAT-C model and tested it for simulating both particulate organic C (POC) and dissolved organic C (DOC) fluxes using 4 years of monthly observations (2014–2017) in the Tuckahoe watershed (TW) in the U.S. Mid-Atlantic region. Results: Sensitivity analyses show that parameters that regulate POC deposition in river networks are more sensitive than those that determine C resuspension from sediments. Further analyses indicate that allochthonous contributions to POC and DOC are about 36.6 and 46 kgC ha –1 year –1 , respectively, while autochthonous contributions are less than 0.72 kgC ha –1 year –1 for both POC and DOC (less than 2% of allochthonous sources). The net deposition of POC on the riverbed (i.e., 11.4 kgC ha –1 year –1 ) retained ca. 31% of terrestrial inputs of POC. In addition, average annual buried C was 0.34 kgC ha –1 year –1 , accounting for only 1% of terrestrial POC inputs or 3% of net POC deposition. The results indicate that about 79% of deposited organic C was converted to inorganic C (CH 4 and CO 2 ) in the sediment and eventually released into the overlying water column. Conclusion: This study serves as an exploratory study on estimation of C fluxes from terrestrial to aquatic environments at the watershed scale. We demonstrated capabilities of the SWAT-C model to simulate C cycling from uplands to riverine ecosystems and estimated C sinks and sources in aquatic environments. Overall, the results highlight the importance of including carbon cycle dynamics within the riverbed in order to accurately estimate aquatic carbon fluxes and stocks. The new capabilities of SWAT-C are expected to serve as a useful tool to account for those processes in watershed C balance assessment.
Exploratory experimental study on neutral charge low energy particle irradiation of selected thermal control coatings
Space environment simulation tests to determine neutral charge low energy particle irradiation effects on spacecraft aluminum and zinc thermal control coatings
Exploratory experimental study of the effects of inlet conditions on the flow and containment characteristics of coaxial flows
Short chamber inlet configuration for eddy elimination in coaxial flow reactor of gaseous core nuclear rockets
Exploratory plasmadynamic studies of vortex and coaxial flow geometries employing radiofrequency induction heating
Vortex and coaxial flow of argon and helium plasmas heated inductively, and strong magnetic field effects on turbulent plasma mixing, for gas core reactors
An exploratory simulation study of a head-up display for general aviation lightplanes
The concept of a simplified head-up display referred to as a landing-site indicator (LASI) for use in lightplanes is discussed. Results of a fixed-base simulation study exploring the feasibility of the LASI concept are presented in terms of measurements of pilot performance, control-activity parameters, and subjective comments of four test subjects. These subjects, all of whom had various degrees of piloting experience in this type aircraft, performed a series of simulated landings both with and without the LASI starting from different initial conditions in the final approach leg of the landing maneuver.
Exploratory Contrail Studies: Transonic Truss-Braced Wing (TTBW) Contrail Assessment & National Airspace System (NAS) Impacts from Contrail Avoidance
Aviation is projected to become an increasingly large contributor to greenhouse gas emissions. Condensation trails (contrails) are visible cloud trails of water vapor made from aircraft engine exhaust. One study estimated that persistent contrails have contributed about 57% of total Effective Radiative Forcing from aviation operations. Airspace management can reduce persistent contrails and related climate change impacts. NAS Digital Twin simulation capability and Autoresolver conflict management service can be utilized to investigate persistent contrail formation avoidance. On three of the four days analyzed, TTBW persistent contrail formation length was about 10 percentage points less than Boeing 737-800 (around 3% vs 13%). On average, altitude change maneuvers in simulation reduced persistent contrail formation length by 69.8% for 0.4% increase in fuel burn and 1.2% increase in flight duration.
Improving undergraduate astronomy students’ skills with research literature via accessible summaries: An exploratory case study with Astrobites-based reading assignments
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Using Octupoles for Background Control in Linear Colliders - an Exploratory Conceptual Study (LCC-0009)
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Flying Schedule-Matching Descents to Explore Flight Crews' Perceptions of Their Load and Task Feasibility
Multiple studies have investigated the development and use of ground-based (controller) tools to manage and schedule traffic in future terminal airspace. No studies have investigated the impacts that such tools (and concepts) could have on the flight-deck. To begin to redress the balance, an exploratory study investigated the procedures and actions of ten Boeing-747-400 crews as they flew eight continuous descent approaches in the Los Angeles terminal airspace, with the descents being controlled using speed alone. Although the study was exploratory in nature, four variables were manipulated: speed changes, route constraints, clearance phraseology, and winds. Despite flying the same scenarios with the same events and timing, there was at least a 50 second difference in the time it took crews to fly the approaches. This variation is the product of a number of factors but highlights potential difficulties for scheduling tools that would have to accommodate this amount of natural variation in descent times. The primary focus of this paper is the potential impact of ground scheduling tools on the flight crews performance and procedures. Crews reported "moderate to low" workload, on average; however, short periods of intense and high workload were observed. The non-flying pilot often reported a higher level of workload than the flying-pilot, which may be due to their increased interaction with the Flight Management Computer, when using the aircraft automation to assist with managing the descent clearances. It is concluded that ground-side tools and automation may have a larger impact on the current-day flight-deck than was assumed and that studies investigating this impact should continue in parallel with controller support tool development.
Flight-Deck Strategies and Outcomes When Flying Schedule-Matching Descents
Recent studies at NASA Ames Research Center have investigated the development and use of ground-based (air traffic controller) tools to manage and schedule air traffic in future terminal airspace. An exploratory study was undertaken to investigate the impacts that such tools (and concepts) could have on the flight-deck. Ten Boeing 747-400 crews flew eight optimized profile descents in the Los Angeles terminal airspace, while receiving scripted current day and futuristic speed clearances, to ascertain their ability to fly schedulematching descents without prior training. Although the study was exploratory in nature, four variables were manipulated: route constraints, winds, speed changes, and clearance phraseology. Despite flying the same scenarios with the same events and timing, there were significant differences in the time it took crews to fly the approaches. This variation is the product of a number of factors but highlights potential difficulties for scheduling tools that would have to accommodate this amount of natural variation in descent times. The focus of this paper is the examination of the crews' aircraft management strategies and outcomes. This includes potentially problematic human-automation interaction issues that may negatively impact arrival times, speed and altitude constraint compliance, and energy management efficiency.
Assessing the Potential of Social Networks as a Means for Information Diffusion the Weatherization Experiences (WE) Project.
In April 2009, U.S. Department of Energy (DOE) formally tasked Oak Ridge National Laboratory (ORNL) with conducting two impact and process evaluations of DOE’s Weatherization Assistance Program (WAP), known as the retrospective and American Recovery and Reinvestment Act of 2009 (ARRA) period evaluations, respectively. The former focused on WAP Program Year (PY) 2008, which covers the period from April 2008 to June 2009. The latter focused on PY 2010. This report presents in-depth analyses from ORNL’s social network study, the Weatherization Experiences (WE) Project, an exploratory study conducted as part of the ARRA period WAP evaluation. The WE Project explored the potential for WAP recipients and staff to influence energy savings beyond their homes and day jobs. Several studies conducted through ORNL’s evaluation of WAP found that the program has the ability to profoundly impact the lives of the people it serves (Tonn et al. 2014b). Recipients of WAP provided statements ranging from the newfound ability to pay utility bills and prescription medication to reduced emergency department visits for asthma and medical conditions associated with thermal stress. Through this exploratory research project, the stories of hundreds of weatherization recipients and providers were documented. The WE Project was designed to further investigate whether or not shared experiences with weatherization have the power to stimulate home energy saving action within an individual’s social network.