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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Developing an Interactive Landscape for Mobility Resources: Preprint

As the world continues to be increasingly driven by data, the ways researchers and professionals sort and collect this data is critical. In the world of mobility data, new levels of data from public transportation systems, location services, and other means are being lost due to how little organization exists. Much of the data is proprietary, and there are few if any de jure or even de facto standards connecting data. There is also little knowledge about the gaps that exist in the data. In this project, we created an interactive landscape where mobility resources are categorized and organized in an easy to use, living document. We made this landscape with open-source code from the CNCF Cloud Native Landscape and repurposed it to the mobility data's needs. Additionally, unlike previous sources that organize mobility data, this document can be updated through GitHub by those in the field to keep its sources relevant. Following the creation of a beta version of the landscape, we conducted several interviews with industry researchers and professionals to ensure the landscape would be useful. The result is an online hub where mobility researchers and resource creators can easily access research and collaborate.

ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2021

Fungal and bacterial growth variation due to drought and nitrogen addition experimental treatments. Loma Ridge Experimental Project. 2010-2012

Terrestrial ecosystem models assume that microbial communities respond instantaneously, or are immediately resilient, to environmental change. Here we tested this assumption by quantifying the resilience of a leaf litter community to changes in precipitation or nitrogen availability. By manipulating composition within a global change experiment, we decoupled the legacies of abiotic parameters versus that of the microbial community itself. After one rainy season, more variation in fungal composition could be explained by the original microbial inoculum than the litterbag environment (18% versus 5.5% of total variation). This compositional legacy persisted for 3 years, when 6% of the variability in fungal composition was still explained by the microbial origin. In contrast, bacterial composition was generally more resilient than fungal composition. Microbial functioning (measured as decomposition rate) was not immediately resilient to the global change manipulations; decomposition depended on both the contemporary environment and rainfall the year prior. Finally, using metagenomic sequencing, we showed that changes in precipitation, but not nitrogen availability, altered the potential for bacterial carbohydrate degradation, suggesting why the functional consequences of the two experiments may have differed. Predictions of how terrestrial ecosystem processes respond to environmental change may thus be improved by considering the legacies of microbial communities. This data package includes ten csv files (five data files and their corresponding data dictionaries) and one file-level metadata excel file. Data files contains information about which plots were exposed to treatments related to drought and nitrogen, information about litter bags reciprocal transplants manipulation for water input and nitrogen, detail information about water addition, precipitation records, and litter variables collected. Data dictionary files include detail explanation for each column in the data files. The file-level metadata file describes each file mentioned above. All the analyses were done using the R software.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Adsorption of Iodine and Tritium from UNF Reprocessing Off-Gas Streams

The need to control emissions of the gaseous radionuclides to the air during nuclear fuel recycling is widely recognized. Gaseous radionuclides can partition to off-gas streams emanating from the various individual processes used in the recycle plant, such as from the mechanical head end (shear), tritium pretreatment, fuel dissolver, vessel vents, cell ventilation, and conversion operations. In traditional recycle plants, the bulk of the four primary volatile fission products (i.e., {sup 3}H, {sup 14}C, {sup 85}Kr, and {sup 129}I) is released in the head-end processes, for example, the dissolution process. The usual off-gas treatment sequence of operations targets removal of tritium (as {sup 3}HHO), iodine, carbon (as {sup 14}CO{sub 2}), and the noble gases, in that order. Water and iodine are captured first because the other species are relatively unimpeded by the sorbents used for water and iodine, so they flow downstream to additional treatment processes. Water and iodine do react with one another, and many techniques used to collect one of these species also collect some fraction of the other. It is quite desirable to sequester the iodine and water separately because the tritiated water may be disposed of as a low level waste. If not cleanly separated, contamination of the low-level waste by iodine may elevate its classification to high-level waste and result in greater costs for disposal. The proposed sorption sequence was tested in the laboratory. Use of a second column of AgZ permits the detection of breakthrough from the primary AgZ column while protecting the downstream 3AMS column from collecting iodine. (This arrangement is equivalent to enabling intra-column sampling of the primary column.) Neutron activation analysis of the 3AMS revealed that iodine was below, or at, the level of detection. The results successfully demonstrated that iodine can be sequestered in the AgZ while the water is collected free of iodine in the 3AMS column. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2015

Designing Passivating, Carrier-Selective Contacts for Photovoltaic Devices

"The first step towards building a high-efficiency solar cell is to develop an absorber with few recombination-active defects. Many photovoltaic technologies have already achieved this (monocrystalline Si, III-V materials grown on lattice-matched substrates, perovskites, polycrystalline CdTe and CIGS); those that have not (a-Si:H, organics) have been limited to low open-circuit voltage. The second step is to develop contacts that both inhibit surface recombination and allow for low-resistance collection of either only electrons or only holes. For most photovoltaic technologies, this step is both more difficult and less explored than the first, and we are unaware of a prescribed methodology for selecting materials for contacts to solar cells. We elucidate a unified, conceptual understanding of contacts within which existing contacting schemes can be interpreted and future contacting schemes can be imagined. Whereas a split of the quasi-Fermi levels of holes and electrons is required in the absorber of any solar cell to generate a voltage, carriers are eventually collected through a metallic wire in which no such quasi-Fermi-level split exists. We define a contact to be all layers between the bulk of the absorber and the recombination-active interface through which carriers are extracted. The quasi-Fermi levels must necessarily collapse at this interface, and thus the transition between maximal quasi-Fermi-level splitting (in the absorber) and no splitting occurs entirely in the contact. Depending on the solar cell architecture, the contact will usually extend from the surface of the absorber to the surface of a metal or transparent conductive oxide layer, and may include deposited or diffused doped layers (e.g., as in crystalline and thin-film Si cells) and heterostructure buffer layers (e.g., the CdS layer in a CdTe device). We further define a passivating contact as one that enables high quasi-Fermi-level splitting in the absorber (large “internal” voltage), where “high” is relative to the splitting dictated by bulk recombination. Finally, we define a carrier-selective contact as one that enables a high “external” voltage measured across the contacts, where “high” is relative to the internal voltage. With these definitions, passivating contacts are those that allow only electrons, only holes, or neither electrons or holes to transport from the absorber to any position in the contact that has recombination-active defects. An excellent example of this is a SiNx layer on a Si wafer: the layer removes dangling bonds at the wafer surface (where there are both electrons and holes) and does not allow either carrier type to travel to its outermost surface, where there are undoubtedly defects. Carrier-selective contacts are then passivating contacts that also allow for low-impedance flow of either electrons or holes (but not both) to the recombination-active, extracting interface. The most common example is a heavily doped layer that establishes an electric field at the absorber surface, which then “filters” the carriers that may pass to the contact according to the sign of their charge.

14 SOLAR ENERGY↗
DOE OSTI2018

Detecting outliers in streaming time series data from ARM distributed sensors

The Atmospheric Radiation Measurement (ARM) Data Center at ORNL collects data from a number of permanent and mobile facilities around the globe. The data is then ingested to create high level scientific products. High frequency streaming measurements from sensors and radar instruments at ARM sites require high degree of accuracy to enable rigorous study of atmospheric processes. Outliers in collected data are common due to instrument failure or extreme weather events. Thus, it is critical to identify and flag them. We employed multiple univariate, multivariate and time series techniques for outlier detection methods and studied their effectiveness. First, we examined Pearson correlation coefficient which is used to measure the pairwise correlations between variables. Singular Spectrum Analysis (SSA) was applied to detect outliers by removing the anticipated annual and seasonal cycles from the signal to accentuate anomalies. K-means was applied for multivariate examination of data from collection of sensors to identify any deviation from expected and known patterns and identify abnormal observation. The Pearson correlation coefficient, SSA and K-means methods were later combined together in a framework to detect outliers through a range of checks. We applied the developed method to data from meteorological sensors at ARM Southern Great Plains site and validated against existing database of known data quality issues.

Lu, Yuping↗
DOE OSTI2024

Measurement-induced multipartite-entanglement regimes in collective spin systems

We study the competing effects of collective generalized measurements and interaction-induced scrambling in the dynamics of an ensemble of spin-1/2 particles at the level of quantum trajectories. This setup can be considered as analogous to the one leading to measurement-induced transitions in quantum circuits. We show that the interplay between collective unitary dynamics and measurements leads to three regimes of the average Quantum Fisher Information (QFI), which is a witness of multipartite entanglement, as a function of the monitoring strength. While both weak and strong measurements lead to extensive QFI density (i.e., individual quantum trajectories yield states displaying Heisenberg scaling), an intermediate regime of classical-like states emerges for all system sizes where the measurement effectively competes with the scrambling dynamics and precludes the development of quantum correlations, leading to sub-Heisenberg-limited states. We characterize these regimes and the crossovers between them using numerical and analytical tools, and discuss the connections between our findings, entanglement phases in monitored many-body systems, and the quantum-to-classical transition.

Physics↗
NASA NTRS2002

The Effects of Low Sulfate Concentrations on Modern Microbial Mat Communities: A Long Term Manipulation

Microbial mats were widespread during the first ca. 2 Ga. of our biosphere's history. To better understand microbial ecosystems and their biomarkers under the low sulfate levels present in early oceans, we attempted a long-term (ca. 1 year) manipulation of sulfate in modem mats. Mats collected from salt ponds at Guerrero Negro, Baja Calif. Sur were incubated in a Greenhouse "Collaboratory" at Ames. Mats were maintained in artificial seawater brine containing either: 1) sulfate levels normal for these mats (70 mM), or 2) brine in which sulfate was replaced by chloride. Sulfate concentrations in the "low sulfate" brine gradually approached their lowest (to date) value of 0. 1 mM as sulfate was consumed and/or diffused out of the mat over a period of ca. 4 months. During that period of time, a number of differences between the treatments emerged. Relative to the "low sulfate" mats, "normal sulfate" mats had: 1) lower consumption of oxygen in the lower levels of the mat, 2) higher efficiencies of oxygenic photosynthesis, and 3) higher rates of nitrogen fixation. Rates of methane production by the mats increased greatly as sulfate concentrations fell below ca. 0.2 mM. In contrast, "low" and "normal" sulfate mats had similar net rates of exchange of O2 and dissolved inorganic C between the mats and overlying water. Reduced sulfate levels have diverse impacts upon these ecosystems.

Bebout, Brad↗
DOE OSTI2018

REE and Coal Open Geodatabase Collection

The REE and Coal Open Database is an online collection of subsurface contextual data from publicly available geological, geochemical, and geospatial resources. These data align to and support execution of NETL’s REE coal assessment method. The database includes basin- and national-level spatial datasets, in addition to other non-spatial data that support the assessment approach. Data in this collection are sourced from a range of authoritative, public sources, including NETL, U.S. Geological Survey (USGS), Energy Information Administration (EIA), and state geological surveys.

coal↗
DOE OSTI2020

IER 268 CED-3b Report

The goal of IER 268 was to collect information from the operation of the Godiva IV super-prompt critical assembly to support multi-physics modeling efforts. There were two types of systems deployed. One was a Photo-Doppler Velocimetry (PDV) system which used the reflection of laser light on the surface of the Godiva IV core. The other consisted of an MHD 240 detector with two other detectors (an MHD-241 and an Eljen EJ-325A) used for reference as the MHD-240 detector was moved. The collection is referred to as the MHD Detector in the narrative log. There were two types of Godiva operations performed to gather data. A series of super-prompt critical bursts were performed and data collected on both systems, tied to a common trigger. Separately, a series of delayed critical operations at various power levels was performed for a combination of MHD detector distances from Godiva and the presence and absence of a shield in the line of sight between Godiva and the MHD detector. This data was collected to determine the contribution of room return during the burst measurements.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Economic Impacts from Wind Energy in Colorado Case Study: Rush Creek Wind Farm

This economic impact analysis of the Rush Creek Wind Farm 1) quantitatively modeled the gross economic impacts at the Colorado state-level and four-county region and 2) engaged with community members to draw specific insight on how wind development impacts their local economy. This study also provides useful insights on the economic impacts supported by Colorado's wind energy manufacturing and supply chain. The Rush Creek Wind Farm was Colorado's largest wind energy project in 2018. Jobs, gross domestic product, gross economic output, and earnings were estimated using the National Renewable Energy Laboratory's Jobs and Economic Development Impact (JEDI) model. Researchers also engaged with communities near the Rush Creek Wind Farm to collect empirical economic data as well as first-hand knowledge of community-level impacts during wind farm construction. The case studies and qualitative research in this report provide context for the quantitative JEDI model results, describing the economic impacts to rural communities.

17 WIND ENERGY↗
DOE OSTI2011

Material and energy recovery in integrated waste management systems: Project overview and main results

Highlights: > The source separation level (SSL) of waste management system does not qualify adequately the system. > Separately collecting organic waste gives less advantages than packaging materials. > Recycling packaging materials (metals, glass, plastics, paper) is always attractive. > Composting and anaerobic digestion of organic waste gives questionable outcomes. > The critical threshold of optimal recycling seems to be a SSL of 50%. - Abstract: This paper describes the context, the basic assumptions and the main findings of a joint research project aimed at identifying the optimal breakdown between material recovery and energy recovery from municipal solid waste (MSW) in the framework of integrated waste management systems (IWMS). The project was carried out from 2007 to 2009 by five research groups at Politecnico di Milano, the Universities of Bologna and Trento, and the Bocconi University (Milan), with funding from the Italian Ministry of Education, University and Research (MIUR). Since the optimization of IWMSs by analytical methods is practically impossible, the search for the most attractive strategy was carried out by comparing a number of relevant recovery paths from the point of view of mass and energy flows, technological features, environmental impact and economics. The main focus has been on mature processes applicable to MSW in Italy and Europe. Results show that, contrary to a rather widespread opinion, increasing the source separation level (SSL) has a very marginal effects on energy efficiency. What does generate very significant variations in energy efficiency is scale, i.e. the size of the waste-to-energy (WTE) plant. The mere value of SSL is inadequate to qualify the recovery system. The energy and environmental outcome of recovery depends not only on 'how much' source separation is carried out, but rather on 'how' a given SSL is reached.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2000

BOREAS TF-8 NSA-OJP and SSA-OBS Ceilometer Data

The BOREAS TF-8 team used ceilometers to collect data on the fraction of the sky covered with clouds and the cloud height. Included with these data is the surface-based lifting condensation level, derived from temperature and humidity values acquired at the flux tower at the NSA-OJP site. Ceilo-meter data were collected at the NSA-OJP site in 1994 and at the NSA-OJP and SSA-OBS sites in 1996. The data are available in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884).

Moore, Kathleen E.↗
DOE OSTI2015

Assessing the use of reflectance spectroscopy in determining CsCl stress in the model species Arabidopsis thaliana

Here, reflectance spectroscopy is a rapid and non-destructive analytical technique that may be used for assessing plant stress, and has potential applications for use in remediation. Changes in reflectance such as that due to metal stress may occur before damage is visible, and existing studies have shown that metal stress does cause changes in plant reflectance. To further investigate the potential use of reflectance spectroscopy as a method for assessing metal stress in plants, an exploratory study was conducted in which Arabidopsis thaliana plants were treated twice weekly in a laboratory setting with varying levels (0, 0.5, or 5 mM (millimolar)) of caesium chloride (CsCl) solution, and reflectance spectra were collected every week for three weeks using an Analytical Spectral Devices FieldSpec Pro spectroradiometer with both a contact probe (CP) and a field of view (FOV) probe at 36.8 and 66.7 cm, respectively, above the plant. Plants were harvested each week after spectra collection for determination of relative water content and chlorophyll content. A visual assessment of the plants was also conducted using point observations on a uniform grid of 81 points. A mixed-effects model analysis was conducted for each vegetation index (VI) considered to determine the effects of length of treatment, treatment level, view with which spectra were acquired, and the interactions of these terms. Two-way analyses of variance (ANOVAs) were performed on the aforementioned endpoints (e.g. chlorophyll content) to determine the significance of the effects of treatment level and length of treatment. Multiple linear regression (MLR) was used to develop a predictive model for each endpoint, considering VI acquired at each view (CP, high FOV, and low FOV). Of the 14 VI considered, 8 were included in the MLR models. Contact probe readings and FOV readings differed significantly, but FOV measurements were generally consistent at each height.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Mobility Energy Productivity Evaluation of Prediction-Based Vehicle Powertrain Control Combined with Optimal Traffic Management

Transportation vehicle and network system efficiency can be defined in two ways: 1) reduction of travel times across all the vehicles in the system, and 2) reduction in total energy consumed by all the vehicles in the system. The mechanisms to realize these efficiencies are treated as independent (i.e., vehicle and network domains) and, when combined, they have not been adequately studied to date. This research aims to integrate previously developed and published research on Predictive Optimal Energy Management Strategies (POEMS) and Intelligent Traffic Systems (ITS), to address the need for quantifying improvement in system efficiency resulting from simultaneous vehicle and network optimization. POEMS and ITS are partially independent methods which do not require each other to function but whose individual effectiveness may be affected by the presence of the other. In order to evaluate the system level efficiency improvements, the Mobility Energy Productivity (MEP) metric is used. MEP specifically measures the connectedness of a system while accounting for time and energy externalities of modes that provide mobility in a given location. A SUMO model is developed to reflect real traffic patterns in Fort Collins, Colorado and data is collected by a probe SUMO vehicle which is validated against data collected on a real vehicle driving the same routes through the city. Individual vehicle and system level efficiencies are calculated using SUMO outputs for scenarios which integrate POEMS and ITS independently as well as jointly. Results from application of POEMS and ITS show improvement in energy consumption and travel times respectively when compared to the respective baseline scenarios. Our conclusion is that there are promising synergistic benefits to travel time and energy efficiency when POEMS and ITS are combined.

ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2014

Metals in tissues of migrant semipalmated sandpipers (Calidris pusilla) from Delaware Bay, New Jersey

There is an abundance of field data on levels of metals for feathers in a variety of birds, but relatively few data for tissues, especially for migrant species from one location. In this paper we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in muscle, liver, brain, fat and breast feathers from migrant semipalmated sandpipers (Calidris pusilla) collected from Delaware Bay, New Jersey. Our primary objectives were to (1) examine variation as a function of tissue, (2) determine the relationship of metal levels among tissues, and (3) determine the selenium:mercury molar ratio in different tissues since selenium is thought to protect against mercury toxicity. We were also interested in whether the large physiological changes that occur while shorebirds are on Delaware Bay (e.g. large weight gains in 2–3 weeks) affected metal levels, especially in the brain. There were significant differences among tissues for all metals. The brain had the lowest levels of arsenic and cadmium, and was tied for the lowest levels of all other metals except lead and selenium. Correlations among metals in tissues were varied, with mercury levels being positively correlated for muscle and brain, and for liver and breast feathers. Weights vary among individuals at the Delaware Bay stopover, as they arrive light, and gain weight prior to migration north. Bird weight and levels of arsenic, cadmium, and selenium in the brain were negatively correlated, while they were positively correlated for lead. There was no positive correlation for mercury in the brain as a function of body weight. The selenium:mercury molar ratio varied significantly among tissues, with brain (ratio of 141) and fat having the highest ratios, and liver and breast feathers having the lowest. In all cases, the ratio was above 21, suggesting the potential for amelioration of mercury toxicity. - Highlights: • Metal levels were examined for migrant semipalmated sandpipers. • There were differences in metal levels among internal tissues. • Brain had the lowest levels of arsenic and cadmium. • Bird weight and arsenic, cadmium, and selenium levels in brain were negatively correlated. • Selenium:mercury molar ratio varied among tissues (21–141, suggesting protection)

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2000

BOREAS Level-3p Landsat TM Imagery: Geocoded and Scaled At-sensor Radiance

For BOReal Ecosystem-Atmosphere Study (BOREAS), the level-3p Landsat Thematic Mapper (TM) data were used to supplement the level-3s Landsat TM products. Along with the other remotely sensed images, the Landsat TM images were collected in order to provide spatially extensive information over the primary study areas. This information includes radiant energy, detailed land cover, and biophysical parameter maps such as Fraction of Photosynthetically Active Radiation (FPAR) and Leaf Area Index (LAI). Although very similar to the level-3s Landsat TM products, the level-3p images were processed with ground control information, which improved the accuracy of the geographic coordinates provided. Geographically, the level-3p images cover the BOREAS Northern Study Area (NSA) and Southern Study Area (SSA). Temporally, the four images cover the period of 20-Aug-1988 to 07-Jun-1994. Except for the 07-Jun-1994 image, which contains seven bands, the other three contain only three bands.

Nickeson, Jaime↗
NASA NTRS2015

Status: Crewmember Noise Exposures on the International Space Station

The International Space Station (ISS) provides a unique environment where crewmembers from the US and our international partners work and live for as long as 6 to 12 consecutive months. During these long-durations ISS missions, noise exposures from onboard equipment are posing concerns for human factors and crewmember health risks, such as possible reductions in hearing sensitivity, disruptions of crew sleep, interference with speech intelligibility and voice communications, interference with crew task performance, and reduced alarm audibility. It is crucial to control acoustical noise aboard ISS to acceptable noise exposure levels during the work-time period, and to also provide a restful sleep environment during the sleep-time period. Acoustic dosimeter measurements, obtained when the crewmember wears the dosimeter for 24-hour periods, are conducted onboard ISS every 60 days and compared to ISS flight rules. NASA personnel then assess the acoustic environment to which the crewmembers are exposed, and provide recommendations for hearing protection device usage. The purpose of this paper is to provide an update on the status of ISS noise exposure monitoring and hearing conservation strategies, as well as to summarize assessments of acoustic dosimeter data collected since the Increment 36 mission (April 2013). A description of the updated noise level constraints flight rule, as well as the Noise Exposure Estimation Tool and the Noise Hazard Inventory implementation for predicting crew noise exposures and recommending to ISS crewmembers when hearing protection devices are required, will be described.

Limardo-Rodriguez, Jose G.↗
NASA NTRS1989

A system architecture for a planetary rover

Each planetary mission requires a complex space vehicle which integrates several functions to accomplish the mission and science objectives. A Mars Rover is one of these vehicles, and extends the normal spacecraft functionality with two additional functions: surface mobility and sample acquisition. All functions are assembled into a hierarchical and structured format to understand the complexities of interactions between functions during different mission times. It can graphically show data flow between functions, and most importantly, the necessary control flow to avoid unambiguous results. Diagrams are presented organizing the functions into a structured, block format where each block represents a major function at the system level. As such, there are six blocks representing telecomm, power, thermal, science, mobility and sampling under a supervisory block called Data Management/Executive. Each block is a simple collection of state machines arranged into a hierarchical order very close to the NASREM model for Telerobotics. Each layer within a block represents a level of control for a set of state machines that do the three primary interface functions: command, telemetry, and fault protection. This latter function is expanded to include automatic reactions to the environment as well as internal faults. Lastly, diagrams are presented that trace the system operations involved in moving from site to site after site selection. The diagrams clearly illustrate both the data and control flows. They also illustrate inter-block data transfers and a hierarchical approach to fault protection. This systems architecture can be used to determine functional requirements, interface specifications and be used as a mechanism for grouping subsystems (i.e., collecting groups of machines, or blocks consistent with good and testable implementations).

Smith, D. B.↗