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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Basin-Wide Approaches to Hydropower Licensing

This presentation summarizes findings from a 2020 NREL technical report including the FERC relicensing process for non-federal hydropower projects, analyzes FERC-licensed projects with license expiration dates from 2018-2037, discusses FERC's authority to coordinate license terms of hydropower projects within a shared river basin and provides basin-wide case studies and considerations to hydropower relicensing. In the United States there are 1,043 active FERC-licensed hydroelectric projects with a total capacity of 56,097 MW. Of those, 647 with a total capacity of 21,870 MW have license expiration dates from 2018-2037. The expected workload in conjunction with the time, cost, and complexity associated with issuing a single new license has led to initiatives that aim to increase the efficiency of the relicensing process. Federal and state regulators and licensees in California, Maine, New York, and Wisconsin have begun to develop approaches to look at hydropower relicensing as part of a larger system - a river basin. These basin-wide approaches seek to coordinate different stages of the relicensing process for multiple projects at the same time. The goal of these basin-wide approaches is to increase the efficiency of the relicensing process and allow for a more comprehensive analysis of the cumulative impacts of the projects within the basin. These innovative approaches to relicensing could also reduce the workload for regulators and costs associated with relicensing. This presentation discusses some of the findings from the Basin-wide Approaches to Hydropower Relicensing: Case Studies and Considerations including a summary of the key considerations for the FERC relicensing process for non-federal hydropower projects, key findings from the analysis of FERC-licensed projects with license expiration dates from 2018-2037, discusses FERC's authority to coordinate license terms of hydropower projects within a shared river basin and provides basin-wide case studies and considerations to hydropower relicensing.

basin-wide↗
DOE OSTI2023

Using Life Cycle Assessment to Inform CBI Research Priorities

Life cycle assessment (LCA) is used within the Center for Bioenergy Innovation (CBI) to provide information about how feedstock agricultural practices, supply chain logistics, biorefinery operating parameters, and the slate of biofuels and products contribute to environmental impacts, and how CBI's research priorities can result in less impactful biofuel supply chains. This poster provides an overview of the LCA methodology used within CBI and focuses on data needs in general and from other CBI teams. Assumptions and simplifications within biofuel LCA studies are reviewed, including options for modeling multi-functional processes. Calculation details for life cycle environmental impacts used within CBI - global warming potential, cumulative energy demand, and the Available Water Remaining indicator - are presented, along with a discussion of carbon intensity as an alternative metric for evaluating sustainable aviation fuel and other biofuels. The process of interpreting impact results to guide research priorities is discussed, with examples drawn from CBI's upcoming manuscript on switchgrass yield and cell wall composition.

bioenergy↗
DOE OSTI2024

Relating Measured Component Damage to Assessed Component Reliability in Reliability Integrity Management (RIM)

There is currently no widely agreed detailed general method for licensing a novel plant incorporating novel materials (or materials being deployed in novel environments); in many such situations, there are no directly applicable engineering code cases for decision-makers (including regulators) to rely on. It may be possible to develop an approach to licensing such a plant that is based on the Reliability and Integrity Management (RIM) approach delineated in ASME BPVC Section XI Division 2. NRC Regulatory Guide 1.246, Rev.0, endorses, with conditions, the subject portion of the ASME Code. But that portion of the ASME code is written at a very high level, and there are fundamental technical challenges associated with applying it literally to licensing a real plant. In the RIM approach, applicants need to do the following (among other things): • Allocate target reliabilities to structures, systems, and components (SSCs) that collectively support the top-level plant safety and availability objectives; • Understand failure modes of those SSCs, and the degradation mechanisms that could lead to those failure modes; • Develop and propose a program of surveillances that will identify degradation prior to failure of SSCs; • Provide a means of reporting results, taking actions for anomalous or undesirable conditions, and give the regulator assurance of continued safe operations. Applying RIM in a specific case will call for advances in the state of practice of relating physical observables to functional reliability of certain component types. Except where a given level of damage corresponds to a failed (or nearly failed) state, it is not practical to establish a precise quantitative relationship between physical observables and reliability. This paper focuses on managing risk of passive component failures based on observable damage parameters. A simple approach to cumulative damage modeling will be illustrated with a view to possible use in RIM applications.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2024

Environmental and economic analyses of chemical recycling via dissolution of waste polyethylene terephthalate

Globally, more than 1000 organizations and 175 nations are facing the plastic waste problem and have realized the need to transition from “linear-to-circular” economy of plastics. While the current mechanical recycling technologies for plastics are struggling to increase the U.S. plastic recycling rates beyond 9%, chemical recycling technologies become important complementary technologies to the predominant mechanical recycling that are needed to realize the circular economy in plastics supply chains. Dissolution is one such chemical recycling technology that can recycle waste plastic back into high-quality virgin grade plastic. However, the environmental and economic impacts of chemical recycling of waste polyethylene terephthalate (PET) via dissolution technology using a green solvent are unknown. Our study evaluated environmental metrics such as greenhouse gas (GHG) emissions and cumulative energy demand, and economic metrics such as net present value (NPV), minimum selling price, payback period, return on investment, and discounted internal rate of return for three dissolution processes with polymer recovery via anti-solvent, evaporation, and cooling precipitation techniques. The dissolution process with evaporation technique was the most economically favorable, whereas that with cooling technique was the most environmentally favorable. The anti-solvent approach had low economic performance and the highest environmental impacts. The NPV for all of these technologies ranged from $2.67 MM to $10.93 MM for a capacity of 8,400 MT/year and was found to be the highest for dissolution with evaporation approach and the least for anti-solvent approach. The cradle-to-gate GHG emissions and energy demand for PET dissolution processes ranged from 1.33-3.77 kg CO2-eq/kg of chemically recycled (CR) PET and18.9-56.1 MJ/kg of CR-PET, respectively. These economic and environmental metrics will be helpful in evaluating the sustainability of circular PET supply chains in the U.S.

09 BIOMASS FUELS↗
DOE OSTI2022

Stable High‐Conductivity Ethylenedioxythiophene Polymers via Borane‐Adduct Doping

Efficient doping of polymer semiconductors is required for high conductivity and efficient thermoelectric performance. Lewis acids, e.g., B(C 6 F 5 ) 3 , have been widely employed as dopants, but the mechanism is not fully understood. 1:1 “Wheland type” or zwitterionic complexes of B(C 6 F 5 ) 3 are created with small conjugated molecules 3,6-bis(5-(7-(5-methylthiophen-2-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)thiophen-2-yl)-2,5-dioctyl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione [oligo_DPP(EDOT) 2 ] and 3,6-bis(5''-methyl-[2,2':5',2''-terthiophen]-5-yl)-2,5-dioctyl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione [oligo_DPP(Th) 2 ]. Using a wide variety of experimental and computational approaches, the doping ability of these Wheland Complexes with B(C 6 F 5 ) 3 are characterized for five novel diketopyrrolopyrrole-ethylenedioxythiophene (DPP-EDOT)-based conjugated polymers. The electrical properties are a strong function of the specific conjugated molecule constituting the adduct, rather than acidic protons generated via hydrolysis of B(C 6 F 5 ) 3 , serving as the oxidant. It is highly probable that certain repeat units/segments form adduct structures in p -type conjugated polymers which act as intermediates for conjugated polymer doping. Electronic and optical properties are consistent with the increase in hole-donating ability of polymers with their cumulative donor strengths. The doped film of polymer (DPP(EDOT) 2 -(EDOT) 2 ) exhibits exceptionally good thermal and air-storage stability. The highest conductivities, ≈300 and ≈200 S cm -1 , are achieved for DPP(EDOT) 2 -(EDOT) 2 doped with B(C 6 F 5 ) 3 and its Wheland complexes.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Nanocellulose‐Carboxymethylcellulose Electrolyte for Stable, High‐Rate Zinc‐Ion Batteries

Abstract Aqueous Zn ion batteries (ZIBs) are one of the most promising battery chemistries for grid‐scale renewable energy storage. However, their application is limited by issues such as Zn dendrite formation and undesirable side reactions that can occur in the presence of excess free water molecules and ions. In this study, a nanocellulose‐carboxymethylcellulose (CMC) hydrogel electrolyte is demonstrated that features stable cycling performance and high Zn 2+ conductivity (26 mS cm −1 ), which is attributed to the material's strong mechanical strength (≈70 MPa) and water‐bonding ability. With this electrolyte, the Zn‐metal anode shows exceptional cycling stability at an ultra‐high rate, with the ability to sustain a current density as high as 80 mA cm −2 for more than 3500 cycles and a cumulative capacity of 17.6 Ah cm −2 (40 mA cm −2 ). Additionally, side reactions, such as hydrogen evolution and surface passivation, are substantially reduced due to the strong water‐bonding capacity of the CMC. Full Zn||MnO 2 batteries fabricated with this electrolyte demonstrate excellent high‐rate performance and long‐term cycling stability (>500 cycles at 8C). These results suggest the cellulose‐CMC electrolyte as a promising low‐cost, easy‐to‐fabricate, and sustainable aqueous‐based electrolyte for ZIBs with excellent electrochemical performance that can help pave the way toward grid‐scale energy storage for renewable energy sources.

25 ENERGY STORAGE↗
DOE OSTI2020

Thermal Management by Engineering the Alignment of Nanocellulose

One of the grand current research challenges is to improve the energy efficiency of residential and commercial buildings, which cumulatively consume more than 40% of the energy generated globally. In addition to improving the comfort of the inhabitants and mitigating the growing energy consumption problem, new building materials and technologies could provide a safe strategy for geoengineering to mitigate global climate change. Herein, recent progress in developing such advanced materials from nanocellulose, which is often derived from wood or even dirty feedstocks like waste, is reviewed. By using chemical and bacteria-enabled processing, nanocellulose can be used to fabricate broadband photonic reflectors, thermally super-insulating aerogels, solar gain regulators, and low-emissivity coatings, with potential applications in windows, roofs, walls, and other components of buildings envelopes. These material developments draw inspiration from advanced energy management found in nature, such as the nanoporous photonic structures that evolved in cuticles of beetles. Fabrication of such materials takes advantage of mesoscale liquid crystalline self-assembly, which allows for pre-designed control of cellulose nanoparticle orientations at the mesoscale. Finally, with the potential fully realized, such materials could one day transform the current energy-lossy buildings into energy plants on Earth and possibly even enable extraterrestrial habitats.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Sequential Dual Alignments Introduce Synergistic Effect on Hexagonal Boron Nitride Platelets for Superior Thermal Performance

Planarly aligning 2D platelets is challenging due to their additional orientational freedom compared to 1D materials. Here, this study reports a sequential dual-alignment approach, employing an extrusion-printing-induced shear force and rotating-magnetic-field-induced force couple for platelet planarly alignment in a yield-stress support bath. It is hypothesized that the partial alignment induced by a directional shear force facilitates subsequent axial rotation of the platelets for planar alignment under an external force couple, resulting in a synergistic alignment effect. This sequential dual-alignment approach achieves better planar alignment of 2D modified hexagonal boron nitride (mhBN). Specifically, the thermal conductivity of the 40 wt% mhBN/epoxy composite is significantly higher (692%) than that of unaligned composites, surpassing the cumulative effect of individual methods (only 133%) with a 5 times more synergistic effect. For 30, 40, and 50 wt% mhBN composites, the thermal conductivity values (5.9, 9.5, and 13.8 W m –1 K –1 ) show considerable improvement compared to the previously reported highest values (5.3, 6.6, and 8.6 W m –1 K –1 ). Additionally, a 3D mhBN/epoxy heat sink is printed and evaluated to demonstrate the feasibility of device fabrication. The approach enables the planar alignment of electrically or thermally conducting 2D fillers during 3D fabrication.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Engineering Electrical Transport by Implantation‐Induced Defects in CrN Films Without Affecting Thermal Conductivity

The transport properties of CrN thin films deposited on sapphire have been tailored through structural modifications induced by cumulative argon implantation. As-grown samples experience the typical structural transition in CrN films from orthorhombic at low temperature to cubic above the Néel temperature (≈280 K) and exhibit a metallic-like conduction in both phases. With increasing implantation dose, the conduction mode shifts to a semiconductor-like behavior in both phases, albeit at different damage levels. Analysis of the results suggests that hopping conduction becomes dominant beyond a given damage threshold. The results highlight a promising correlation between defect engineering and conduction mechanisms, offering valuable insights into the versatile electrical properties of CrN films. These implantation-induced defects scatter carriers, leading to a decrease in their mobility. As the implantation dose increases, the defect landscape evolves, modifying the density of states. However, up to a dose of 0.050 dpa, no significant influence on phonon scattering is observed. This approach demonstrates that ion implantation enables precise tuning of CrN's electrical properties without affecting thermal conductivity, offering valuable insights into defect engineering in transition metal nitrides and underscoring its potential for transport properties decorrelation.

defects↗
DOE OSTI2026

Active Learning‐Driven Inkless Additive Nanomanufacturing for Printed Electronics

Inkless additive nanomanufacturing for printed electronics promises broad material and substrate versatility, yet the high-dimensional print parameter space makes tuning print parameters time-intensive. We present a Bayesian optimization study that constructs a digital twin from printed-silver data to benchmark surrogate models, acquisition functions, and batch sizes head-to-head to achieve user-specified target resistance. Tested surrogate models included Gaussian process, random forest, and Bayesian neural network surrogates with expected improvement and confidence bound acquisition functions. In total, we evaluate 48 unique model configurations alongside a random sampling baseline for comparison. For printed silver, the Bayesian neural network with a batch size of one achieved the lowest average cumulative regret, approximately four times more efficient on average than random sampling. To balance performance and substrate space, a random forest model with expected improvement and a batch size of four was chosen as the model for validation testing. Applying this chosen configuration to copper with an additional print parameter, the model achieved a resistance within 0.15 Ω of a 1 Ω target in fewer than 30 printed lines across five validation sets. Altogether, the workflow yields a tuned and validated model that efficiently guides experiments toward the target while simultaneously learning the parameter space.

Bevel, Colton [Auburn University, AL (United State↗
DOE OSTI2021

Ultrahigh-Rate and Long-Life Zinc–Metal Anodes Enabled by Self-Accelerated Cation Migration

Aqueous zinc ion batteries are receiving unprecedented attention owing to their markedly high safety and sustainability, yet their lifespan particularly at high rates is largely limited by the poor reversibility of zinc (Zn) metal anodes, due to the random ion diffusion and sluggish ion replenishment at reaction interface. In this work, we propose a tunnel-rich and corona-poled ferroelectric thin film coating for Zn metal anode to tackle above conundra. It is demonstrated that the poled ferroelectric coating can better deconcentrate and self-accelerate ion migration at coating/Zn interface upon electroplating process than untreated ferroelectric coating and bare Zn, thus enabling a compact and horizontally-aligned Zn morphology even at ultrahigh rates. Notably, a maximal cumulative plating capacity of over 6500 mAh cm -2 (at 10 mA cm -2 ) is achieved for the surface-modified Zn metal anode, showing extraordinary reversibility of Zn plating/stripping. This work provides new insights in stabilizing Zn metal electrodeposition at the scale of interfacial ion diffusion.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2022

Triggering Anionic Redox Activity in Li 3 NbS 4 Through Cationic Disordering or Substitution

Extensive utilization of Li-ion batteries for varieties of applications necessitates ceaseless improvements of electrode materials for achieving higher energy density. Towards this goal, Li-rich layered oxides exhibiting high capacity due to cumulated cationic and anionic redox activities are under study for nearly a decade. Still, several unanswered questions remain with respect to these Li-driven anionic redox reactions in terms of the activation process and long-term consequences upon cycling. Here, the Li-rich Li 3 NbS 4 phase is focused, and synthesized as two different polymorphs, namely ordered and disordered phases. From analyses of their chemical and electrochemical properties, a crystal-electronic structure relationship is unraveled that triggers the anionic redox activity in these compounds. Moreover, through complementary theoretical calculations, the capability of cationic disorder to trigger anionic redox activity via the hybridization of cationic and non-bonding anionic energy levels is shown. This finding is further supported by the appearance of anionic redox activity by introducing the disorder through cationic substitution. Altogether, the insights derived here can help in designing new anionic redox materials with optimum performances for practical applications.

25 ENERGY STORAGE↗
DOE OSTI2022

Very small-scale, segregating-fluidized-bed experiments: A dataset for CFD-DEM validation and uncertainty quantification

IWe report fluidization experiments were conducted on a small scale and with a rapid response (short duration) to enable corresponding simulations at low-computational cost. Rise times are reported for four or fewer polyethylene particles (intruders) in an air-fluidized bed of ~5000 group D glass beads. Experimental inputs were completely characterized—particle properties, system dimensions and operating conditions—which is necessary for validating computational fluid mechanics (CFD)-discrete element method (DEM) including a comprehensive uncertainty quantification (UQ) analysis. Input uncertainties are reported as bounds or cumulative distribution functions of measured values. The staggering number of simulations required to complete a UQ analysis (~O[10 4 ] simulations corresponding to ~5 uncertain inputs) motivates this study. These segregating-bed experiments are designed to permit analogous CFD-DEM simulations to complete in less than a day on a single (~2.5 GHz) computational processor unit (CPU). Segregation times are reported for several operating conditions, intruder sizes, and initial configurations, providing a rich dataset for numerical model testing, validation and UQ.

42 ENGINEERING↗
DOE OSTI2023

Relaxing the constant molar overflow assumption in distillation optimization

Abstract The constant molar overflow (CMO) framework, while useful for shortcut distillation models, assumes that all components have the same latent heats of vaporization. A simple transformation, from molar flows to latent‐heat flows, allows shortcut models to retain the mathematical simplicity of the CMO framework while accounting for different latent heats, resulting in the constant heat transport (CHT) framework for adiabatic distillation columns. Although several past works have already proposed this transformation in the literature, it has not been well utilized in recent times. In this article, we show the utility of this transformation in upgrading various applications such as identifying energy‐efficient multicomponent distillation configurations based on heat duty rather than surrogate vapor flow. The method transforms the diagram to a diagram. Furthermore, we derive new and insightful analytical results in distillation, such as cumulative latent‐heat stage fractions having monotonic profiles within a distillation column under the CHT framework.

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

Surface Density Dependent Catalytic Activity of Single Palladium Atoms Supported on Ceria

The analogy between single-atom catalysts (SACs) and molecular catalysts predicts that the specific catalytic activity of these systems is constant. Here we provide evidence that this prediction is not necessarily true. As a case in point, we show that the specific activity over ceria-supported single Pd atoms linearly increases with metal atom density, originating from the cumulative enhancement of CeO 2 reducibility. The long-range electrostatic footprints (≈1.5 nm) around each Pd site overlap with each other as surface Pd density increases, resulting in an observed deviation from constant specific activity. These cooperative effects exhaust previously active O atoms above a certain Pd density, leading to their permanent removal and a consequent drop in reaction rate. The findings of our combined experimental and computational study show that the specific catalytic activity of reducible oxide-supported single-atom catalysts can be tuned by varying the surface density of single metal atoms.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Environmental Metrics of Ethanol Production Improve with Increased Biomass Yield and Carbohydrate Content in Populus Trichocarpa

When selecting economically and environmentally advantageous genotypes for domestication in a biofuel supply chain, variability of cell-wall composition within a feedstock population and its impact on biorefinery metrics must be understood. We performed a life cycle assessment (LCA) on a poplar-to-ethanol supply chain to quantify global warming potential and cumulative energy demand as affected by variable carbohydrate content in a large representative natural variant population of Populus trichocarpa. The results showed that both environmental metrics decrease with increasing tree size and with increasing biomass carbohydrate content. These trends parallel prior economic results and provide clear direction to breeders or genetic engineers when improving poplar cultivars.

09 BIOMASS FUELS↗
DOE OSTI2025

Temporal Galactose‐Manganese Feeding in Fed‐Batch and Perfusion Bioreactors Modulates UDP‐Galactose Pools for Enhanced mAb Glycosylation Homogeneity

ABSTRACT Monoclonal antibodies (mAbs) represent a majority of biotherapeutics in the market today. These glycoproteins undergo posttranslational modifications, such as N‐linked glycosylation, that influence the structural & functional characteristics of the antibody. Glycosylation is a heterogenous posttranslational modification that may influence therapeutic glycoprotein stability and clinical efficacy, which is why it is often considered a critical quality attribute (CQA) of the mAb product. While much is known about the glycosylation pathways of Chinese Hamster Ovary (CHO) cells and how cell culture chemical modifiers may influence the N‐glycosylation profile of the final product, this knowledge is often based on the final cumulative glycan profile at the end of the batch process. Building a temporal understanding of N‐glycosylation and how mAb glycoform composition responds to real‐time changes in the biomanufacturing process will help build integrated process models that may allow for glycosylation control to produce a more homogenous product. Here, we look at the effect of specific nutrient feed media additives (e.g., galactose, manganese) and feeding times on the N‐glycosylation pathway to modulate N‐glycosylation of a Herceptin biosimilar mAb (i.e., Trastuzumab). We deploy the N‐GLYcanyzer process analytical technology (PAT) to monitor glycoforms in near real‐time for bench‐scale bioprocesses operated in both fed‐batch and perfusion modes to build an understanding of how temporal changes in mAb N‐glycosylation are dependent on specific media additives. We find that Trastuzumab terminal galactosylation is sensitive to media feeding times and intracellular nucleotide sugar pools. Temporal analysis reveals an increased desirable production of single and double galactose‐occupied glycoforms over time under glucose‐starved fed‐batch cultures. Comparable galactosylation profiles were also observed between fed‐batch (nutrient‐limited) and perfusion (non‐nutrient‐limited) bioprocess conditions. In summary, our results demonstrate the utility of real‐time monitoring of mAb glycoforms and feeding critical cell culture nutrients under fed‐batch and perfusion bioprocessing conditions to produce higher‐quality biologics.

Biotechnology & Applied Microbiology↗
DOE OSTI2022

Hydrothermal synthesis of chiral carbon dots

Abstract Nanocolloids that are cumulatively referred to as nanocarbons, attracted significant attention during the last decade because of facile synthesis methods, water solubility, tunable photoluminescence, easy surface modification, and high biocompatibility. Among the latest development in this reserach area are chiral nanocarbons exemplified by chiral carbon dots (CDots). They are expected to have applications in sensing, catalysis, imaging, and nanomedicine. However, the current methods of CDots synthesis show often contradictory chemical/optical properties and structural information that required a systematic study with careful structural evaluation. Here, we investigate and optimize chiroptical activity and photoluminescence of L‐ and D‐ CDots obtained by hydrothermal carbonization of L‐ and D‐ cysteine, respectively. Nuclear magnetic resonance spectroscopy demonstrates that they are formed via gradual dehydrogenation and condensation reactions of the starting amino acid leading to particles with a wide spectrum of functional groups including aromatic cycles. We found that the chiroptical activity of CDots has an inverse correlation with the synthesis duration and temperature, whereas the photoluminescence intensity has a direct one, which is associated with degree of carbonization. Also, our studies show that the hydrothermal synthesis of cysteine in the presence of boric acid leads to the formation of CDots rather than boron nitride nanoparticles as was previously proposed in several reports. These results can be used to design chiral carbon‐based nanoparticles with optimal chemical, chiroptical, and photoluminescent properties.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗