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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 OSTI2024

Hanford Site Freshwater Mussel Monitoring Report for Calendar Year 2022

The U.S. Department of Energy, Richland Operations Office (DOE-RL) conducts ecological monitoring on the Hanford Site to collect and maintain data needed to ensure compliance with an array of environmental laws, regulations, and policies governing DOE-RL activities. Ecological monitoring data provides baseline information about the plants, animals, and habitats under DOE-RL stewardship at the Hanford Site that is required for decision making under the National Environmental Policy Act of 1969 and Comprehensive Environmental Response, Compensation, and Liability Act of 1980. In addition, ecological monitoring helps ensure that DOE-RL, its contractors, and other entities conducting activities on the Hanford Site are in compliance with the Hanford Site Comprehensive Land Use Plan (DOE/EIS-0222-F). DOE-RL places priority on monitoring those plant and animal species or habitats with specific regulatory protections or requirements that are rare and/or declining (federal or state listed endangered, threatened, or sensitive species) or are of significant interest to federal, state, or tribal governments or the public.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Molecular design principles of Lysine-DOPA wet adhesion

The mussel byssus has long been a source of inspiration for the adhesion community. Recently, adhesive synergy between flanking lysine (Lys, K) and 3,4-Dihydroxyphenylalanine (DOPA, Y ) residues in the mussel foot proteins (Mfps) has been highlighted. However, the complex topological relationship of DOPA and Lys as well as the interfacial adhesive roles of other amino acids have been understudied. Herein, we study adhesion of Lys and DOPA-containing peptides to organic and inorganic substrates using single-molecule force spectroscopy (SMFS). We show that a modest increase in peptide length, from K Y to (K Y ) 3 , increases adhesion strength to TiO 2. Surprisingly, further increase in peptide length offers no additional benefit. Additionally, comparison of adhesion of dipeptides containing Lys and either DOPA (K Y ) or phenylalanine (KF) shows that DOPA is stronger and more versatile. We furthermore demonstrate that incorporating a nonadhesive spacer between (K Y ) repeats can mimic the hidden length in the Mfp and act as an effective strategy to dissipate energy.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

HydroBio: Hydropower Capacity and Freshwater Biodiversity in Conterminous United States Sub-basins

This dataset summarizes existing and potential hydropower capacity and freshwater biodiversity at the sub-basin level throughout the conterminous United States (CONUS). It contains descriptive information regarding each sub-basin (e.g., 8-digit hydrologic unit code identifier, name, states, and size) along with sub-basin-level summaries of: 1) existing hydropower capacity (MW), 2) potential nominal non-powered dam (NPD) capacity (MW), 3) potential capacity of new stream reach development (NSD) (MW), and 4) freshwater biodiversity, including the total richness of fish, crayfish, and mussels and metrics that account for how rare and threatened those species tend to be. Hydropower data were obtained from Oak Ridge National Laboratory data resources (Existing Hydropower Assets, Non-Powered Dam Technical Potential, and New Stream Reach Development). Freshwater biodiversity data were obtained from NatureServe. Sub-basin characteristic information was obtained from the United States Geological Survey. Additionally, long data that provide lists of unique elements within each sub-basin for each constituent data resource (e.g., NatureServe, Existing Hydropower Assets) are provided to enhance dataset utility for users. The dataset provides, for the first time, a national-level assessment of existing and potential hydropower capacity in the context of freshwater biodiversity and is a valuable resource for stakeholders tasked with providing affordable, reliable energy to the American public while maintaining or enhancing invaluable freshwater resources. The dataset contains six data files in comma separated (*.csv) format that are within a zipped file.

Bozeman, Bryan [Oak Ridge National Laboratory (ORN↗
DOE OSTI2024

Ion‐Specific Interactions Engender Dynamic and Tailorable Properties in Biomimetic Cationic Polyelectrolytes

Abstract Biomaterials such as spider silk and mussel byssi are fabricated by the dynamic manipulation of intra‐ and intermolecular biopolymer interactions. Organisms modulate solution parameters, such as pH and ion co‐solute concentration, to effect these processes. These biofabrication schemes provide a conceptual framework to develop new dynamic and responsive abiotic soft material systems. Towards these ends, the chemical diversity of readily available ionic compounds offers a broad palette to manipulate the physicochemical properties of polyelectrolytes via ion‐specific interactions. In this study, we show for the first time that the ion‐specific interactions of biomimetic polyelectrolytes engenders a variety of phase separation behaviors, creating dynamic thermal‐ and ion‐responsive soft matter that exhibits a spectrum of physical properties, spanning viscous fluids to viscoelastic and viscoplastic solids. These ion‐dependent characteristics are further rendered general by the merger of lysine and phenylalanine into a single, amphiphilic vinyl monomer. The unprecedented breadth, precision, and dynamicity in the reported ion‐dependent phase behaviors thus introduce a broad array of opportunities for the future development of responsive soft matter; properties that are poised to drive developments in critical areas such as chemical sensing, soft robotics, and additive manufacturing.

Aubrecht, Filip J.↗
DOE OSTI2022

An algorithm for detecting and quantifying disturbance and recovery in high-frequency time series

Determining when a disturbance has occurred, its severity, and when the system recovered, is important to numerous questions in the aquatic sciences. This problem can be conceptualized as the timing and degree of perturbation from a typical state, and when the system returns to that typical state. We present an algorithm for detecting disturbance and recovery designed for high-frequency time series, e.g., data produced by automated sampling devices in instrumented buoys and flux towers. The algorithm quantifies differences in the empirical cumulative distribution functions of moving windows over reference and evaluation periods, and is sensitive to changes in the mean, variance, and higher statistical moments. Tests on simulated data show it accurately identifies disturbance and recovery. Three case studies illustrate the application of our algorithm in different empirical settings. A case study on dissolved oxygen in a Florida, USA estuary following a hurricane identified the disturbance and recovery 73 d later. A case study on air temperature and net ecosystem exchange in the Florida everglades identified cold snaps coinciding with periods of reduced carbon uptake. A case study on rotifer abundance following zebra mussel invasion in the Hudson River, NY showed rotifer collapse following invasion and recovery over a decade later. Methods such as ours can improve understanding response to disturbance and facilitate comparative and synthetic study of disturbance impacts across ecosystems.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Ionic Liquid Facilitated Solvent‐Phase Polymerization of Ultrasmooth Coatings of Polycatecholamines

Mussel-inspired polycatecholamine coatings and films have proven to be versatile materials for surface modification. However, the progress of chemically modified coatings with tailored properties has been slow due to the lack of definitive evidence of their polymeric structure. Polycatecholamines form aggregates during polymerization, and their formation mechanism has been a subject of debate owing to their insolubility in traditional molecular solvents. Exploiting the capability of ionic liquids (ILs) to exhibit strong electrostatic interactions, herein, the first solution-phase polymerization approach is reported to achieve polymerization of four catecholamines – dopamine (DA), norepinephrine (NE), L-3,4-dihydroxyphenylalanine (L-DOPA), and adrenaline (AD). Kinetic control over the polymerization process in the solution phase enabled it to follow the process with 1 H NMR spectroscopy, revealing the formation of structural features of resulting complex heterogeneous and soluble polymers. The polymers are both covalent and associative in nature. Solution phase polymerization prevented the formation of large aggregates in the solution, thus facilitating the formation of coatings that are ultra-smooth and have root mean square roughness of the order of sub-nm to nm scale.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Bioinspired design toward nanocellulose-based materials

Nature provides lots of inspiration for material and structural design for various applications. Deriving design principles from the investigation of nature can provide a rich source of inspiration for the development of multifunctional materials. The bioinspired design templates mainly include mussels, nacre, and various plant species. As a sustainable and renewable feedstock, nanocellulose can be used to fabricate advanced materials with multifunctional properties through bioinspired designs. However, challenges and opportunities remain for realizing the full potential in the design of novel materials. Here, this article reviewed recent development in the bioinspired nanocellulose based materials and their application. This article summarizes the functions (e.g., surface wetting) and applications (e.g., composite) of bioinspired nanocellulose-based materials. The bioinspired design templates are discussed along with strategies, advantages, and challenges to the development of synthetic mimics. Additionally, mechanisms and processes (e.g., chemical modification, self-assembly) leading to biomimetic design are discussed. Finally, future research directions and opportunities of bioinspired nanocellulose-based materials are highlighted.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Toughening by Nanodroplets: Polymer–Droplet Biocomposite with Anomalous Toughness

The development of new polymer composites is highly dependent on the design of novel fillers that can bring more benefits in the design and control of structure–property–function than conventional solid particles. Here, inspired by the unique coupling structures of tough mussel byssus, we employ nanodroplets of high-boiling-point oligomers as the liquid filler to fabricate a new class of polymer–droplet composites (PDCs). The combination of nanodroplets and chain end/tail modifier in PDCs finally generates soft-coupling structures with chain ends coupled by the nanodroplets. With this strategy, brittle poly(lactic acid) is successfully transformed into a tough bioplastic with toughness improved by over 2000% via a minimal amount of the modifiers (1.5 wt %). Moreover, the composites show unexpected speed-enhanced energy absorption capability. A soft-coupling toughening mechanism is further proposed for the first time to understand the PDCs’ mechanical properties. This work also indicates the potential of nanodroplets as a new tool for tuning the mechanical properties and even functions of polymer composites.

36 MATERIALS SCIENCE↗
DOE OSTI2021

In situ mechanical reinforcement of polymer hydrogels via metal-coordinated crosslink mineralization

Biological organic-inorganic materials remain a popular source of inspiration for bioinspired materials design and engineering. Inspired by the self-assembling metal-reinforced mussel holdfast threads, we tested if metal-coordinate polymer networks can be utilized as simple composite scaffolds for direct in situ crosslink mineralization. Starting with aqueous solutions of polymers end-functionalized with metal-coordinating ligands of catechol or histidine, here we show that inter-molecular metal-ion coordination complexes can serve as mineral nucleation sites, whereby significant mechanical reinforcement is achieved upon nanoscale particle growth directly at the metal-coordinate network crosslink sites.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Low friction bio-inspired polydopamine/polytetrafluoroethylene coating performance in hydrodynamic bearings

Purpose Low friction polymer coatings able to withstand high loadings and many years of continuous operation are difficult to formulate at low cost, but could find many applications in industry. This study aims to analyze and compare friction and wear performance of novel polydopamine/polytetrafluoroethylene (PDA/PTFE) and traditional tin Babbitt coatings applied to an industrial journal bearing. Design/methodology/approach This paper tested PTFE based coating, co-deposited with PDA, a biopolymer allowing sea mussels to adhere to ocean rocks. This coating was deposited on flat steel substrates and on a curved cast iron hydrodynamic journal bearing surface. The flat substrates were analyzed with a tribometer and an optical microscope, while the coated bearing liners were tested in an industrial laboratory setting at different speeds and different radial loads. Findings PDA/PTFE coating showed 2-3 times lower friction compared to traditional tin Babbitt for flat substrates, but higher friction in the bearing liners. PDA/PTFE also showed considerable wear through coating delamination and abrasion in the bearing liners. Research limitations/implications Five future modifications to mitigate coating flaws are provided, which include modifications to coating thickness and its surface finish. Originality/value While the novel coating showed excellent results on flat substrates, coating performance in a large scale bearing was found to be poor. This study shows that coating preparation needs to be improved to avoid frictional losses and unwanted damage to bearings. We provide several routes that could improve coating performance in industrial applications.

Engineering↗
DOE OSTI2024

Time-series metagenomics reveals changing protistan ecology of a temperate dimictic lake

Abstract Background Protists, single-celled eukaryotic organisms, are critical to food web ecology, contributing to primary productivity and connecting small bacteria and archaea to higher trophic levels. Lake Mendota is a large, eutrophic natural lake that is a Long-Term Ecological Research site and among the world’s best-studied freshwater systems. Metagenomic samples have been collected and shotgun sequenced from Lake Mendota for the last 20 years. Here, we analyze this comprehensive time series to infer changes to the structure and function of the protistan community and to hypothesize about their interactions with bacteria. Results Based on small subunit rRNA genes extracted from the metagenomes and metagenome-assembled genomes of microeukaryotes, we identify shifts in the eukaryotic phytoplankton community over time, which we predict to be a consequence of reduced zooplankton grazing pressures after the invasion of a invasive predator (the spiny water flea) to the lake. The metagenomic data also reveal the presence of the spiny water flea and the zebra mussel, a second invasive species to Lake Mendota, prior to their visual identification during routine monitoring. Furthermore, we use species co-occurrence and co-abundance analysis to connect the protistan community with bacterial taxa. Correlation analysis suggests that protists and bacteria may interact or respond similarly to environmental conditions. Cryptophytes declined in the second decade of the timeseries, while many alveolate groups (e.g., ciliates and dinoflagellates) and diatoms increased in abundance, changes that have implications for food web efficiency in Lake Mendota. Conclusions We demonstrate that metagenomic sequence-based community analysis can complement existing efforts to monitor protists in Lake Mendota based on microscopy-based count surveys. We observed patterns of seasonal abundance in microeukaryotes in Lake Mendota that corroborated expectations from other systems, including high abundance of cryptophytes in winter and diatoms in fall and spring, but with much higher resolution than previous surveys. Our study identified long-term changes in the abundance of eukaryotic microbes and provided context for the known establishment of an invasive species that catalyzes a trophic cascade involving protists. Our findings are important for decoding potential long-term consequences of human interventions, including invasive species introduction.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Scale up, Field testing, and Optimization of Nontoxic, Durable, Economical Coatings for Control of Biofouling and Corrosion (Abstract Only)

The objective of this project is the technical maturation and demonstration of a durable, economical, and nontoxic coating, Superhydrophobic Lubricant Infused Composite (SLIC), that will prevent fouling organisms from growing on marine and hydrokinetic (MHK) structures and prevent invasive mussels from growing on hydropower structures. SLIC technology was developed and patented by PNNL. It combines multiple antifouling mechanisms to provide excellent antifouling performance, durability, and low hydrodynamic drag without using toxic materials. Advanced proof-of-concept testing and demonstrations completed during a Phase 1 TCF project attracted industry interest and partnerships for this Phase 2 effort focused on maturation of a commercial product. Specific tasks and tests will shift the development emphasis to optimizing formulations, validating antifouling performance to address specific application needs, explore compatibility with other paint systems, develop a product with useful shelf life (in can), and determine curing times and effective applications methodology. Phase 2 efforts will focus upon technology transfer and commercialization of the technology with the industrial team. Industrial partners now include a coatings development specialist (Lorama), hydrophobic material manufacturer and paint developer (Dry Surface Technologies), nontoxic biodegradable lubricants manufacturer (BioBlend), and aquatic applications specialists (Prometheus Innovations, River Connectivity Systems). Engagement with the MHK device developers, the PNNL Marine and Coastal Research Laboratory (MCRL) test site in Sequim WA, Bureau of Reclamation, and Taylor Shellfish throughout the project will provide topical expertise and field test sites that will deliver crucial real-world performance data. Through this Phase 2 effort, SLIC will transition from a Technical Readiness Level (TRL) 5 to TRL 6 and long-term performance data will be acquired through demonstrations. The field test data will allow optimization of SLIC formulation to enhance performance (e.g., durability) and packaging, which are key de-risking activities for technology transfer and ultimately to the production of a viable commercial product.

13 HYDRO ENERGY↗
DOE OSTI2024

Impact of Biofouling on Point Absorber Wave Energy Converter Performance and Control

Biofouling is a well-documented problem in naval engineering, but little is known about its effect on wave energy converter (WEC) performance. In this study, the software WEC-Sim is used to simulate the performance of a point absorber WEC that has been biofouled by “hard” species (e.g., mussels, barnacles) to varying degrees. Specifically, biofouling is assumed to change the nonlinear drag forces acting on the WEC, which have quantifiable effects on key performance characteristics such as optimal damping conditions, power, peak displacement, and peak velocity. The results of this analysis are then used to discuss strategies for WEC control as it relates to biofouling. Furthermore, the results show that average power production can decrease by as much as 15% with heavy biofouling and require an adjustment of the optimal control law by up to 20%.

Biofouling↗
DOE OSTI2020

Clearance rates of freshwater bivalves Corbicula fluminea and Utterbackia imbecillis in the presence and absence of light

Light affects bivalve behavior and gaping activity, but its potential effects on bivalve filtration remain poorly investigated. In this paper, clearance rates of two bivalve species: the Asian clam, Corbicula fluminea and the paper pondshell, Utterbackia imbecillis, were assessed in light (6.5 ± 0.5 µmol m -2 s -1 ) and dark (0.0 µmol m -2 s -1 ) conditions. We found that clearance rates remained similar between C. fluminea (50 ± 18 mL g -1 h -1 ) and U. imbecillis (41 ± 10 mL g -1 h -1 ) during light conditions. However, C. fluminea (110 ± 15 mL g -1 h -1 ) filtered significantly faster than U. imbecillis (24 ± 6 mL g -1 h -1 ) in the dark condition (p < 0.05). The results indicated that light might affect the filtration activity in freshwater bivalves differently, depending on species.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

The effects of food quantity, light, and temperature on clearance rates in freshwater bivalves (Cyrenidae and Unionidae)

Assessing the environmental variables that influence freshwater bivalve filtration activity is key to better understand the functioning of stream ecosystems. Here, the effects of light (0 ± 0 µmol m –2 s –1 and 19 ± 2 µmol m –2 s –1 ) and temperature (10, 15, 20 and 25°C) on the clearance rates of two bivalve species: the Asian clam Corbicula fluminea (Cyrenidae) and pocketbook Lampsilis ovata (Unionidae) were assessed under controlled laboratory conditions at two different concentrations of algal food (i.e., 10,000 cells ml –1 and 100,000 cells ml –1 ). Clearance rates for C. fluminea varied from 0 to 491 ml g –1 h –1 , while the observed range for L. ovata was 0 to 905 ml g –1 h –1 . We found that the relative contribution of the tested variables was species-dependent. While temperature plays a major role in the clearance rates of C. fluminea , food concentration was the most significant variable in the clearance rate of L. ovata . Our results confirm the complex interactions between abiotic and biotic factors in freshwater bivalve filtration activity. Overall, clearance rates are highly variable especially in C. fluminea and presumably regulated by other untested factors suggesting high plasticity in filtration.

59 BASIC BIOLOGICAL SCIENCES↗