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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 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Ecosystems and Networks Integrated with Genes and Molecular Assemblies (ENIGMA). Final report

The goal of the Stahl lab is to use a combination of isotopic, genomic, and activity-based analyses in the field, of selected field isolates, and defined synthetic communities to identify sources and sinks of different nitrogen species in the field, focusing on the FRC at the ORNL. The most general research objective is to characterize variants in the pathway for denitrification among field isolates and synthetic microbial assemblies as a foundation for predicting the biotic and abiotic controls of nitrogen and carbon transformations in the field. Specifically, we have focused on characterizing environmental controls of nitrous oxide emissions, an important greenhouse gas and ozone depleting molecule. Studies have mapped the flux of nitrous oxide and controlling genetic elements within the FRC subsurface, indicating the importance of different enzyme variants in nitrous oxide production and consumption in controlling surface emissions. We have developed methods to quantify and catalog the isotopic signatures imparted on nitrous oxide by different nitrous oxide reductase variants in isolated organisms and model synthetic communities. We have developed methods to quantify and catalog the nitrous oxide affinity of field relevant isolates and their biomass yield when respiring nitrous oxide on different carbon substrates. We continue to expand the collection of field-relevant microbial isolates within ENIGMA by focused enrichment and isolation from field material. These objectives have been facilitated by the development of new technologies, including: 1) the development of a multiplexed automated optical density measurement system for quantifying growth kinetics of microorganisms dependent on gaseous substrates in monoculture or gas exchange in synthetic communities and 2) the development of a microcalorimetric analysis format to quantify the impact of environmental stress on microbial maintenance energy. Since field relevant processes are mediated by assemblies of organisms interacting with each other and their local environment, we have also collaborated with other ENIGMA investigators on the assembly and characterization of synthetic communities. These studies have evaluated the role of organisms lacking a complete pathway for denitrification in the control of field processes, measuring process rates of assemblies of organisms that individually lack the full denitrification pathway but mediate the complete denitrification when growing together. These efforts have so far resulted in the publication of 18 peer reviewed papers ranging from ecological and physiological drivers of pathway optimization to field-scale process characterization.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Life cycle of carbon in macroalgae for various products

This paper seeks to understand the life cycle and permanence of carbon sequestration for the many possible products of offshore cultivated macroalgae, compared to natural growth, habitat restoration, and intentional sinking. The paper will systematically review existing life cycle analyses (LCAs) for various macroalgae products to identify information gaps and compare the carbon sequestration potential throughout each product life cycle. The sequestration potential of macroalgae is well documented (e.g. Chung et al., 2011; Krause-Jensen & Duarte, 2016) but the permanence of the capture is not understood for harvested macroalgae or end products, which may or may not release the stored carbon dioxide in processing or consumption. This information is necessary to avoid overestimating the benefit and impacts of federal investment in large-scale seaweed aquaculture. The goal of this report is to: 1) Review published LCAs for various macroalgae products and uses; 2) Identify knowledge gaps (experiments and monitoring) to understand the flow of carbon on various time scales; 3) Develop preliminary ranking of macroalgae products by carbon capture effectiveness and permanence.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Retrospective Analysis of Backwater Habitat Availability Using Remote Sensing

Low-velocity channel-margin habitats serve as important nursery habitats for the endangered Colorado pikeminnow (Ptychocheilus lucius) in the middle Green River between Jensen and Ouray, Utah. These habitats, known as backwaters, are associated with emergent sandbars, and are shaped and reformed annually by peak flows. Our recent knowledge about backwater characteristics and dynamics that is summarized in the synthesis report (Grippo et al. 2015) was based on detailed annual survey data from a relatively small sample of backwaters that were collected from 2003 to 2014 and reach-wide evaluations of backwater surface area based on manual interpretation of aerial and satellite imagery. Methods that bridge the gap between the detailed surveys from a small number of backwaters and the reach-wide assessment of their surface area would enable an assessment of the availability of backwater habitats that meet the minimum depth requirements for suitable habitat for Colorado pikeminnow. In 2015 Argonne National Laboratory (Argonne) tested three regression models—linear, multiple, and partial least square (PLS) regression models—for estimating backwater depth using National Agriculture Imagery Program (NAIP) imagery collected in July 2006 that covered the Jensen-Ouray reach of the Green River (Hamada and LaGory 2016). The results suggested that a PLS regression model showed high correlation with the reference depth (R 2 = 0.69) and had the most unbiased and consistent estimate of backwater depth. The results also indicated that the PLS model would provide reasonable estimates of the amount of habitat providing a minimum suitable depth of 30 cm for young-of-the-year Colorado pikeminnow, even though absolute depth estimates may be uncertain for backwater areas deeper than approximately 40 cm. The study also provided insights regarding the amount and the selection of calibration and validation (cal-val) data needed for improving the accuracy of depth prediction.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Estimating Channel Width for the Middle Green River Using Remote Sensing

Channel geometry can affect the abundance and quality of fish habitats along rivers in the Colorado River basin. However, previous analyses of sediment transport and channel narrowing in the middle Green River have focused on very limited reaches of the river and have used techniques with varying degrees of resolution, leading to potential problems with interpretation and generalization to the overall reach. The goal of this study is to develop comprehensive baseline information for channel width estimation along the Green River by combining a high-resolution digital elevation model (DEM) derived from Light Detection and Ranging (LiDAR) data and Sentinel-2 multispectral satellite imagery. The objectives are to (1) estimate channel width using Sentinel-2 satellite imagery alone, (2) estimate channel width using the high-resolution DEM with ancillary information extracted from the multispectral imagery, and (3) examine the agreement in channel width estimates between the products derived from the two methods to gain insights for cost effective channel-width monitoring.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Making a Deal with the Devilfish: Biometric-Informed Screening Technology CRADA - 514 (Final Report)

This report documents an investigation into the performance of a novel fish-protection screen intended to prevent small aquatic and marine organisms from entering water intakes in free-flowing water bodies. The proposed prototype screen resembles conventional, slotted fish-protection screens with parallel wires or bars; however, the prototype bars are shaped to mimic the filter elements in the mouths of filter-feeding fishes such as the devil ray (Mobula tarapacana). Millions of years of evolution have perfected these structures to provide energetically efficient and clog-resistant filtering of zooplankton from seawater. The intent of the prototype is to exploit these mechanisms for the protection of similarly sized, or larger, organisms in settings where the freely flowing current is approximately parallel with the screen face (i.e., sweeping flow) and perpendicular to the screen bars.

42 ENGINEERING↗
DOE OSTI2021

DOE Support for the North American meeting of the International Society for Microbial Electrochemistry and Technology

The objective of the North American meeting of the International Society for Microbial Electrochemistry and Technology (NA-ISMET 2021, postponed from 2020 due to COVID-19) was to provide a welcoming space for an interdisciplinary group of researchers, primarily based in North America, to discuss their latest discoveries and innovative ideas on both basic science and applied technology in the field of microbial electrochemistry. After two years of limited travel and research interactions due to COVID-19, an in-person meeting was urgently needed to facilitate conversations and collaborations that help move the field forward. NA-ISMET 2021 was co-organized by Moh El-Naggar from the University of Southern California (USC) and Orianna Bretschger from Aquacycl Inc. The meeting took place on November 17 – 19, 2021 at the Michelson Center for Convergent Biosciences of USC. We hosted a total number of 65 registered participants from across the United States and several international participants. Thanks to the generous support from the Department of Energy, Air Force Office of Scientific Research, Office of Naval Research, the Army Research Office, the ISMET organization, and Gamry Instruments Inc., we were able to waive registration fees for all participants and reduce travel cost for several early-career researchers. The scientific program included 28 talks (16 from early-career researchers) and 24 posters that highlighted recent advances in microbial electrochemistry.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2021

Characterizing the contribution of bioaerosols diversity from complex aerosol particle samples.

Current global change scenarios expect to significantly increase the contribution of pollen to the total organic aerosol budget. In addition, pollen can burst into smaller fragments that are highly efficient as cloud condensation nuclei. However, current climate models still do not incorporate the effects of these particles due to detection and quantification challenges in complex aerosol mixtures. Chemical biomarkers (i.e. fructose) have commonly been used to trace pollen but this approximation can generate false positive results given the large number of shared compounds between different bioaerosols. A previous pilot EMSL experiment performed on pure pollen samples suggested that using a set of metabolites as a fingerprint of bioaerosols could serve to substantially increase detection accuracy over single biomarker approaches. In this proposal we developed novel bioinformatic strategies to characterize and quantify complex pollen mixtures present in the atmosphere. For that, we used diverse machine learning algorithms to analyze metabolic fingerprints from complex mixtures of different pollen acquired with high-resolution mass spectrometry (Orbitrap Q-Exactive). Our preliminary results demonstrated the potential to accurately discern and identify at specific relative abundances different pollen species in complex mixtures. Our research will lead to a significant advancement in the atmospheric chemistry and provide much needed data to improve the accuracy of climate models.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Microbiome controls on harmful algal toxin production in Lake Erie (Final Project Report)

Lawrence Livermore National Laboratory (LLNL) funded this project with the aim to understand how the microbiome influences the toxicity of harmful algal blooms in Lake Erie. Dr. Xavier Mayali from LLNL led the project. Dr. Dragan Isailovic led University of Toledo portion of the project also involving Dr. Thomas Bridgeman, and Dr. Gregory Dick led the portion of the project at the University of Michigan with Dr. Jenan Kharbush.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Harnessing Biomineralization Potential of Metal-Sequestering Bacteria for Rare Earth Elements (REE) Material Synthesis

Extremophilic methylotrophs, such as Methylotuvimicrobium alcaliphilum 20ZR are known for their natural ability to carry out REE capture and uptake. It has been predicted that proteins associated with surface layers facilitate transport and homeostasis of essential metals. Indeed, electron microscopic analysis coupled with antibody staining revealed that cell envelop of metal-grown M. alcaliphilum 20ZR contains metal-binding proteins in the base of the cup-shaped structures of S-layers. While less explored, the proteins associated with S-layers are also predicted to contribute to scavenging of other minerals essential for core metabolism. Here, we employed bottom-up proteomic study to compare the protein content of S-layer fractions of M. alcaliphilum 20ZR cultures grown in the presence and absence trace metals to identify putative components REE-scavenging machinery.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Malleable Thermosets (Vitrimers) from CO 2 and Plants

Fiber-reinforced composite materials are increasingly used to replace heavy metal components in transportation applications for lightweighting purposes. Polymer matrix materials used in automotive parts, such as epoxies, nylons, and polypropylenes, are almost all produced from fossil fuels. Higher performance thermoset composites are generally not repairable and lower-cost thermoplastic composites do not have enough performance to replace steel. Vitrimers are a new class of polymer materials with long shelf life, low waste in production, ease of processing, and repairability that have the potential to break through the high-cost thermoset/low-performance thermoplastic barrier to vehicle light-weighting. Vitrimers also exhibit easier chemical recyclability than conventional thermosets with reversible chemical crosslinking that enables reprocessing of scrap from production and end of life components. Vitrimers are a new class of engineered plastics that are weldable, repairable and recyclable like thermoplastics but have high mechanical properties like thermosets. Bio-based vitrimers have only recently been reported in the academic and patent literature. These materials represent an unusual opportunity to meet both VTO light-weighting targets for low-density, high performance materials and BETO sustainability targets for value-added high-volume applications of bio-fuel byproducts. Also, PNNL researchers have previously demonstrated a process to convert CO 2 into potential vitrimer precursors. Washington State University (WSU) success in demonstration of bio-based vitrimers and recent steps toward commercialization of petroleum-based vitrimers support the opportunity for PNNL success in development of sustainable vitrimer materials for recyclable, high-performance fiber-reinforced composites for the transportation sectors.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Plant Growth Study: Growth of Three Plant Species in 100-OL-1 Operable Unit Soils

Soil contamination from historical application of lead arsenate pesticides persists in the 100-OL-1 Operable Unit (OU) of the U.S. Department of Energy’s Hanford Site in Benton County, Washington. A remedial investigation used a portable X-ray fluorescence analyzer to estimate and map the concentrations of metals in surface soil in the 133 decision units comprising the OU. There is variability in lead and arsenic concentrations among the non-contiguous decision units, and an incomplete understanding of the ecological and human risks from soil contamination. While general screening criteria for lead are reported in literature, limited information is available on the impacts of heavy metals on site-specific plant and animal life. To address this information gap, a study on plant growth in Hanford soils was conducted using native bluegrass (Poa secunda), invasive cheatgrass (Bromus tectorum), and buttercrunch lettuce (Lactuca sativa). The latter is included because it is a common species used in plant growth studies. Soil samples were collected from a single general location within the 100-OL-1 OU, prepared, and categorized as having low, medium, or high concentrations of lead and arsenic, with the high concentration soil having concentrations of up to 3,400 and 790 mg/kg lead and arsenic, respectively. Additionally, a synthetic soil was prepared and used as a control, in accordance with standard plant growth protocols. Fifty-four seeds of each plant species were planted in each of the four soil types following the procedure outlined by the Washington State Department of Ecology. Germination rates and biomass measurements were recorded for 20 days. Both bluegrass and lettuce germination rates appeared to be reduced at the highest lead and arsenic concentrations (Pb: 3400 mg/kg, As: 790 mg/kg), while cheatgrass germination rates were unaffected. Total biomass for all species appeared to be related to the relative concentrations of lead and arsenic in the soil. Results of this growth study agree reasonably well with previous Hanford Site plant growth studies and provide additional data for assessing ecological risk at the Hanford Site.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

The 38 th Annual Interdisciplinary Plant Group Symposium: Enhancing the Resilience of Plant Systems to Climate Change (Meeting Summary)

The University of Missouri’s Interdisciplinary Plant Group held its 38th annual symposium on May 25–27. In short, it was a resounding success! The air was almost electric because of a confluence of events that were particular to this symposium. Not only was there great enthusiasm from students attending their first ever scientific meeting, but this was coupled with excitement and delight exuded by many of our senior invited speakers, who were attending their first in-person meeting since the Covid pandemic began. After a long planning period, and with the ongoing pandemic injecting uncertainty, it was gratifying to see the symposium unfold with such excitement and engagement among participants. The symposium was organized to address the grand challenge of “Enhancing the Resilience of Plant System to Climate Change”, by bringing together experts at the intersections of multiple disciplines to educate our community on the opportunities to develop innovative mitigation strategies and to adapt plants to climate change.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Forensics, Instruments, Turtles & Hot Sauce: The Role of an Isotope Geochemist at LANL [Slides]

Measurable quantities of U in Turtle and Tortoise scute. Turtle samples from areas of known history of radionuclide releases found to have non-natural U isotope signatures. These signatures match what we know about the release of uranium radionuclides at each site. Able to determine quantifiable changes in the U concentration and isotope composition along individual layers of growth (representing seven years of life). Possible correlations with historical releases of U from Oak Ridge site.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Worth More Dead than Alive? Quantifying Necromass Persistence for Terrestrial Carbon Storage

The continuous cycle of plant-associated microbial biomass growth, death, and decay provides a consistent supply of necromass-C throughout the rooting zone of the soil profile. These inputs are obviously important for resource allocation and soil quality, but microbial necromass-C may play a critical, but currently unknown, role in mitigating the impacts of climate change through atmospheric decarbonization. Microbial necromass is the largest terrestrial sink of persistent carbon in soils, thus its fate and preservation will have a major impact on global C budgets. Our current understanding of the ecosystem controls on necromass generation, biogeochemical transformation, and stabilization is lacking. The objective of this project is to explore the specific influence of rhizosphere and necromass inputs on soil carbon pools.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Microbial Competition for Copper: Impacts on Carbon and Nitrogen Cycling

Activities from this DOE sponsored project focused on two general questions: (1) how does competition between microbes for copper affect emissions of greenhouse gasses, especially methane and nitrous oxide? and (2) how does a novel copper-binding compound (methanobactin) made by some methane-oxidizing bacteria bind and reduce metals, as well as what are the regulatory elements involved in controlling methanobactin synthesis? From these efforts, we have conclusively shown that microbial competition for copper does indeed exert significant control on microbial community composition, as well as affects how microbes produce and consume nitrous oxide. We have also developed much better insights into the basis for methanobactin activity, as well as how methanotrophs control its production.

54 ENVIRONMENTAL SCIENCES↗