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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 235 records · Page 13

Utilizing a Common Model Architecture for the Simulation of On-Orbit Human Spaceflight Operations

Advances in computing and simulation technology during the 1980 s promoted the development of multiple simulations for on-orbit human spaceflight operations at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC). By the late 1980 s, it became increasingly clear that redundancy risked leading to inefficiencies in dissemination and incorporation of models across simulations, institutional organizations, and spaceflight programs. Software development tools, such as the Trick Simulation Environment, began to emerge providing a generalized framework for the development, integration, and operation of simulations. Throughout the 1990s, engineering, operations, and training simulations began to migrate to Trick in order to take advantage of a common simulation environment. Due to forecasted reductions in funding to the Shuttle and International Space Station (ISS) programs in the early 2000s, the common framework that arose from this simulation migration was formalized as the Common Model Architecture (CMA). The CMA was established in order to further reduce redundancy, while promoting model sharing and enhancing model integrity. A minimal set of standards for data flows, functional interactions, and model organization based on Trick were defined for those features found to be most important in facilitating model interaction. Model-providing organizations within NASA JSC took ownership of models for their specific areas of expertise, and agreements were reached on common model sharing and usage. This paper describes the evolution of commonality enabled by the Trick Simulation Environment at JSC leading to the CMA, the standards defined by the CMA, a recent CMA simulation example, and potential application of the CMA to NASA s new Exploration program.

Leslie J Quiocho↗

Does Aspartic Acid Racemization Constrain the Depth Limit of the Subsurface Biosphere?

Previous studies of the subsurface biosphere have deduced average cellular doubling times of hundreds to thousands of years based upon geochemical models. We have directly constrained the in situ average cellular protein turnover or doubling times for metabolically active micro-organisms based on cellular amino acid abundances, D/L values of cellular aspartic acid, and the in vivo aspartic acid racemization rate. Application of this method to planktonic microbial communities collected from deep fractures in South Africa yielded maximum cellular amino acid turnover times of approximately 89 years for 1 km depth and 27 C and 1-2 years for 3 km depth and 54 C. The latter turnover times are much shorter than previously estimated cellular turnover times based upon geochemical arguments. The aspartic acid racemization rate at higher temperatures yields cellular protein doubling times that are consistent with the survival times of hyperthermophilic strains and predicts that at temperatures of 85 C, cells must replace proteins every couple of days to maintain enzymatic activity. Such a high maintenance requirement may be the principal limit on the abundance of living micro-organisms in the deep, hot subsurface biosphere, as well as a potential limit on their activity. The measurement of the D/L of aspartic acid in biological samples is a potentially powerful tool for deep, fractured continental and oceanic crustal settings where geochemical models of carbon turnover times are poorly constrained. Experimental observations on the racemization rates of aspartic acid in living thermophiles and hyperthermophiles could test this hypothesis. The development of corrections for cell wall peptides and spores will be required, however, to improve the accuracy of these estimates for environmental samples.

cellular↗

Direct Observation of Modulated Radical Spin States in Metal–Organic Frameworks by Controlled Flexibility

Owing to their switchable spin states and dynamic electronic character, organic-based radical species have been invoked in phenomena unique to a variety of fields. When incorporated in solid state materials, generation of organic radicals proves challenging due to aggregation. Metal–organic frameworks (MOFs) are promising candidates for immobilization and stabilization of organic radicals because of the tunable spatial arrangement of organic linkers and metal nodes, which sequesters the reactive species. Herein, a flexible, redox-active tetracarboxylic acid linker bearing two imidazole units was chosen to construct a new Zr 6 -MOF, NU-910, with scu topology. By exploiting the structural flexibility of NU-910, we successfully modulate the dynamics between an isolated organic radical species and an organic radical π-dimer species in the MOF system. Single-crystal X-ray diffraction analysis reveals that through solvent exchange from N,N-diethylformamide to acetone, NU-910 undergoes a structural contraction with interlinker distances decreasing from 8.32 Å to 3.20 Å at 100 K. Organic radical species on the bridging linkers are generated via UV light irradiation. Direct observation of temperature-induced spin switches from an isolated radical species to a magnetically silent radical π-dimer in NU-910 after irradiation in the solid state was achieved via variable-temperature single-crystal X-ray diffraction and variable-temperature electron paramagnetic resonance spectroscopy. Ultraviolet–visible–near infrared spectroscopy and density functional theory calculations further substantiated the formation of a radical cation π-dimer upon irradiation. As a result, this work demonstrates the potential of using flexible MOFs as a platform to modulate radical spin states in the solid phase.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Collaborative Research and Development Program on Explosive Detection Technology

In September 2013, at the 6th Permanent Coordinating Group Meeting between the U.S Department of Energy (DOE) and the French Institut de Radioprotection et de Sureté Nucléaire (IRSN), France expressed an interest in bilateral cooperation with the United States because its newly revised regulations that require enhanced explosives detection capabilities at nuclear and radiological facilities. In the ensuing years, PNNL (DOE/NNSA) and IRSN sought to identify an area of collaboration within explosives detection that would leverage the specific technical strengths of each organization. Based upon awareness of each other’s technical acumen gleaned from the scientific literature on explosives detection, it was clear that specific organizations within each nation could provide the needed expertise to enable enhancement of explosives detection through a collaborative development effort. The French lnstitut Saint-Louis was determined to be an optimal partner for IRSN to develop a collaboration with DOE/NNSA using PNNL’s detection team in this effort. Thus, the dialog was started between the technical experts at each organization to define where complementary expertise in explosives detection could be best leveraged. The technical plans and objectives of this project were sound with promising results. In the end, the joint action sheet was not implemented. The challenge with executing the project was in the complexity of getting a signed agreement between DOE, IRSN and ISL. Most of the obstacles surrounded the ability to protect intellectual property and obtain an agreement which included all of the parties. At a high level, this report documents the interactions and attempt to develop a cooperative framework for explosives detection development from FY 2014 through FY 2020.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Frozen Freedom: Unleashing Grocery Store Demand Flexibility: Preprint

Grocery stores consumed approximately 3% of total electricity used by commercial buildings in the U.S. in 2018 (EIA 2018), representing a unique end-use load profile characterized by the critical use of refrigerated display cases. Exploring demand response (DR) scenarios in grocery stores presents an opportunity to enhance the efficiency and sustainability of surrounding communities. In addition, recent studies demonstrate that implementing control algorithms considering demand flexibility strategies can lead to load and peak reductions in standalone refrigerated display cases. Because small business grocery stores operate on thin margins, the energy bill cost savings DR might provide could make a positive difference toward continued operations. Still, uncertainty remains about the extent of demand flexibility potential controls could provide when coupling refrigeration with whole building operation. To enhance economic viability and grid stability, it is essential to quantify the load flexibility capability of grocery stores. Advanced controls can optimize energy consumption by responding to load shedding, shifting, and DR events, as well as daily Time-of-Use (TOU) rates without compromising food safety. Using both quantitative data and interviews with community-based organizations, we developed a full-size store model and two small store models with controlled refrigerated cases, HVAC, and lighting systems based on actual grocery store properties. Through simulations, we have assessed load flexibility strategies with varied DR events. The results highlight potential for energy and peak reduction with advanced or basic controls. However, interviews and data indicate that more support is needed to make DR strategies consistently accessible to small grocery stores.

demand flexibility↗

SiC cladding R&D execution plan

To advance the development of accident-tolerant fuel cladding for light-water reactors, the Advanced Fuels Campaign actively addresses the R&D gap between the specialized technological progress in SiC-based composite materials, led by industrial partners, and the fundamental scientific understanding of material behavior under reactor operating conditions. The laboratory activities are systematically organized based on the Development Strategy document, which outlines critical barriers to the use of SiC composites in nuclear energy applications for the coming decade and beyond. To complement the strategy, this execution plan specifies a detailed year-by-year work package and establishes key milestones for assessing progress in technological advancement. This plan has been formulated in collaboration with principal investigators at national laboratories, stakeholders, and industry partners with the goal of closing technology gaps and readying SiC-based cladding technologies for full-scale commercial testing. The research conducted at the national laboratories is categorized into three primary subjects: (1) addressing challenges associated with the performance of SiC cladding under normal operating environments, (2) identifying the failure limits of SiC cladding under accident conditions, and (3) modeling fuel performance for SiC cladding systems. Comprehensive laboratory activities integrate the development of advanced modeling tools for SiC-based cladding systems with experimental validation via integrated testing of multiphysics phenomena. This document lays out the laboratory plan to support the development of SiC-based technologies, which have the potential for significant operational and safety benefits for the U.S. nuclear industry. This plan aligns with industry developer needs, relevant Nuclear Energy University Programs, and Nuclear Energy Advanced Modeling and Simulation Programs to ensure SiC cladding technologies are matured as efficiently as possible and will be maintained and updated to accommodate the dynamically evolving progress of development, capability needs, and resource availability.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Using Data-Science Approaches to Unravel Insights for Enhanced Transport of Lithium Ions in Single-Ion Conducting Polymer Electrolytes

Solid polymer electrolytes have yet to achieve the desired ionic conductivity (>1 mS/cm) near room temperature required for many applications. This target implies the need to reduce the effective energy barriers for ion transport in polymer electrolytes to around 20 kJ/mol. In this work, we combine information extracted from existing experimental results with theoretical calculations to provide insights into ion transport in single-ion conductors (SICs) with a focus on lithium ion SICs. Through the analysis of temperature-dependent ionic conductivity data obtained from the literature, we evaluate different methods of extracting energy barriers for lithium transport. The traditional Arrhenius fit to the temperature-dependent ionic conductivity data indicates that the Meyer–Neldel rule holds for SICs. However, the values of the fitting parameters remain unphysical. Our modified approach based on recent work (Macromolecules 2023, 56, 15, 6051), which incorporates a fixed pre-exponential factor, reveals that the energy barriers exhibit temperature dependence over a wide range of temperatures. Using this approach, we identify anions leading to the energy barriers <30 kJ/mol, which include trifluoromethane sulfonimide (TFSI), fluoromethane sulfonimide (FSI), and boron-based organic anions. In our efforts to design the next generation of anions, which can exhibit the energy barriers <20 kJ/mol, we have performed density functional theory (DFT) based calculations to connect the chemical structures of boron-based anions via the binding energy of cation (lithium)-anion pairs with the experimentally derived effective energy barriers for ion hopping. Not only have we identified a correlation between the binding energy and the energy barriers, but we also propose a strategy to design new boron-based anions by using the correlation. This combined approach involving experiments and theoretical calculations is capable of facilitating the identification of promising new anions, which can exhibit ionic conductivity >1 mS/cm near room temperature, thereby expediting the development of novel superionic single-ion conducting polymer electrolytes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Modulation of π-stacking modes and photophysical properties of an organic semiconductor through isosteric cocrystallization

We report on the control of π-stacking modes (herringbone vs slipped-stack) and photophysical properties of 9,10-bis((E)-2-(pyridin-4-yl)vinyl)anthracene (BP4VA), an anthracene-based organic semiconductor (OSC), by isosteric cocrystallization (i.e., the replacement of one functional group in a coformer with another of “similar” electronic structure) with 2,4,6-trihalophenols (3X-ph-OH, where X = Cl, Br, and I). Specifically, BP4VA organizes as slipped-stacks when cocrystallized with 3Cl-ph-OH and 3Br-ph-OH, while cocrystallization with 3I-ph-OH results in a herringbone mode. The photoluminescence and molecular frontier orbital energy levels of BP4VA were effectively modulated by the presence of 3X-ph-OH through cocrystallization. We envisage that the cocrystallization of OSCs with minimal changes in cocrystal formers can provide access to convenient structural and property diversification for advanced single-crystal electronics.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Literature Data on Foam Fracturing Fluid

At the beginning of this project, the Temple team spent significant effort to collect data relevant to foam fracturing. More than 40 articles/reports were found in the open literature that reported the properties of aqueous foams under various testing conditions. The foam properties included viscosity and stability in terms of half-life, while were influenced by the foam quality, shear rate, temperature, pressure, as well as surfactants and additives used in making the foam base solutions. As a result, more than 1100 data points were collected, which are included in a master worksheet named "Literature data on Foam Fracturing Fluid". These data points are organized based on following parameters: 1. Literature source, including authors and publication year 2. Gaseous phase (e.g. CO2, N2) 3. Liquid phase (e.g. tap water, DI water, salt water) 4. Surfactants and their concentrations 6. Additives 7. Foam quality 8. Pressure 9. Temperature 10. Viscosity 11. Foam stability, which was characterized by its half-life: Half-life Foam study data base with data analysis was completed and a webpage is designed hosted on public server at https://surfactant-dashboard.herokuapp.com

15 GEOTHERMAL ENERGY↗

Marketing information: The technical report as product

Technical reports constitute a product, the primary means for communicating the results of research to the user. The Langley scientific and technical information (STI) review and evaluation project undertook a review of the technical report as an effective product for information communication. Style manuals describing theory and practice in technical report preparation; publication manuals covering such factors as design, layout, and type style; and copies of technical reports were obtained from industrial, academic, governmental, and research organizations. Based on an analysis of this material, criteria will be established for the report components, for the relationship of the components within the report context, and for the overall report organization. The criteria will be used as bench marks and compared with the publication standards currently used to prepare NASA technical reports.

Stoher, F. F.↗

Enhance the performance of organic solar cells by nonfused ring electron acceptors bearing a pendent perylenediimide group

A new nonfused ring electron acceptor PDI-DO-2F is designed and synthesized by attaching perylenediimide (PDI) unit as a pendent group to the central donor core. Compared with the control molecule DO-2F, the introduction of PDI lateral substituent can greatly enhance the solubility and decrease the crystallinity of the resulted acceptor. The PBDB-T:PDI-DO-2F blend film exhibits a much better morphology with higher and more balanced carrier mobility in contrast to PBDB-T:DO-2F one. PDI-DO-2F based organic solar cells (OSCs) give a power conversion efficiency (PCE) of 11.78%, higher than DO-2F based ones (9.82%). Furthermore, PDI-DO-2F based OSCs shows a ΔE non-rad value of 0.23 eV, which is significantly lower than the DO-2F based ones (0.28 eV). More importantly, the addition of PDI-DO-2F as the third component to the PBDB-T:DO-2F binary system can optimize the morphology of blend films and improve the shelf stability of devices. Finally, the PBDB-T:DO-2F:PDI-DO-2F based ternary OSCs achieve a higher PCE of 13.82%.

14 SOLAR ENERGY↗

Halogenated Carboxylates as Organic Anodes for Stable and Sustainable Sodium-Ion Batteries

Organic materials are competitive as anodes for Na-ion batteries (NIBs) due to the low cost, abundance, environmental benignity, and high sustainability. In this paper, we synthesized three halogenated carboxylate-based organic anode materials to exploit the impact of halogen atoms (F, Cl, and Br) on the electrochemical performance of carboxylate anodes in NIBs. The fluorinated carboxylate anode, disodium 2, 5-difluoroterephthalate (DFTP-Na), outperforms the other carboxylate anodes with H, Cl, and Br, in terms of high specific capacity (212 mA h g -1 ), long cycle life (300 cycles), and high rate capability (up to 5 A g -1 ). As evidenced by the experimental and computational results, the two F atoms in DFTP reduce the solubility, enhance the cyclic stability, and interact with Na+ during the redox reaction, resulting in a high-capacity and stable organic anode material in NIBs. Therefore, this work proves that fluorinating carboxylate compounds is an effective approach to developing high-performance organic anodes for stable and sustainable NIBs.

25 ENERGY STORAGE↗

Hydrophobic amine-based binary mixtures of active pharmaceutical and food grade ingredients: characterization and application in indium extraction from aqueous hydrochloric acid media

The wide spread use of hazardous and expensive solvents for the liquid-liquid extraction (LLE) of critical metals has been a growing source of waste in the metal refinement industry. We have developed and characterized room temperature liquid hydrophobic binary mixtures based on common pharmaceutical and food grade compounds as sustainable, cost effective alternatives to both ionic liquids and conventional solvents. Additionally, we introduce liquid mixtures with Proton Sponge® (1,8-bis(dimethylamino)naphthalene), one of the strongest known organic bases. These mixtures have been applied to the LLE of indium(III) ions from hydrochloric acid solutions, displaying an extraction efficiency greater than 99% in some systems. Here, a systematic approach to identifying the underlying mechanism of extraction, in particular relating to the charge, solubility, and complexation of the indium species in the organic phase has been developed.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Using data-science approaches to unravel insights for enhanced transport of lithium ions in single-ion conducting polymer electrolyte

Solid polymer electrolytes have yet to achieve the an ionic conductivity > 1 mS/cm at room temperature for realistic applications. This target implies the need to reduce the effective energy barriers of ion transport in polymer electrolytes to around 20 kJ/mol. In this work, we combine information extracted from existing experimental results with theoretical calculations to provide insights into ion transport in single-ion conductors (SICs) with a focus on lithium ion SICs. Through the analysis of temperature-dependent ionic conductivity data obtained from the literature, we evaluate different methods of extracting energy barriers for lithium transport. The traditional Arrhenius fit to the temperature-dependent ionic conductivity data indicates that the Meyer-Neldel rule holds for SICs. However, the values of the fitting parameters remain unphysical. Our modified approach based on recent work (Macromolecules, 56, 15, 6051(2023)), which incorporates a fixed pre-exponential factor, reveals that the energy barriers exhibit temperature dependence over a wide range of temperatures. Using this approach, we identify a series of anions leading to the energy barriers less than 30 kJ/mol, which include trifluoromethane sulfonimide (TFSI), fluoromethane sulfonimide (FSI), and boron-based organic anions. In our efforts to design the next generation of anions, which can exhibit the energy barriers less than 20 kJ/mol, we focused on boron-containing SICs, and performed density functional theory (DFT) based calculations to connect the chemical structures via the binding energy of cation (lithium)-anion pairs with the experimentally derived effective energy barriers for ion transport. Not only have we identified a correlation between the binding energy and the energy barriers, but we also propose a strategy to design new boron-based anions by using the correlation. This combined approach involving experiments and theoretical calculations is capable of facilitating the identification of promising new anions, which can exhibit ionic conductivity $> 1$ mS/cm near room temperature, thereby expediting the development of novel superionic single-ion conducting polymer electrolytes. The published datasets include all the temperature-dependent ionic conductivity collected from the literature with literature DOIs, DFT calculated binding energies, and python scripts to analyze data, construct statistical models, and generate plots.

36 MATERIALS SCIENCE↗

Acid-base bifunctional porous liquids

Basic solutions are essential for gas-involved catalytic transformations, yet their ultralow free volume limits gas solubility and diffusivity. Engineering permanent porosity in such reactive liquids has remained a longstanding challenge. Here, we introduce a surface-sacrifice strategy that incorporates Brønsted-acidic zeolite nanocrystals into strong organic bases to create permanently porous reactive liquids. Stereochemically controlled acid–base neutralization at the external zeolite surface forms a thin ionic solvation shell that stabilizes the dispersion while fully preserving the internal microporosity and crystallinity of the zeolite framework. The resulting basic media exhibit persistent microporosity, confirmed by inert-gas sorption, 129Xe nuclear magnetic resonance, neutron scattering, and theoretical simulations. These porous liquids show significantly enhanced catalytic performance in CO2 conversion and hydrogenation reactions. The coexisting acidic and basic sites further enable antagonistic cascade catalysis within a single liquid phase. This surface-sacrifice approach provides a general route to introduce permanent porosity into reactive media, enabling boosted gas transformations.

Qiu, Liqi [University of Tennessee, Knoxville (UTK↗

Elucidating non-radiative decay in near-infrared lumiphores: Leveraging new design principles to develop a telecom band organic dye laser

Organic near-infrared (NIR) lumiphores have been targeted for biological and technological applications; however, these dyes exhibit exponentially decreasing quantum yields with decreasing energy gaps. The accepted model of this phenomenon invokes C–H stretching modes as the dominant route of non-radiative energy dissipation. Reducing the number of these modes is a popular strategy for the design of bright NIR lumiphores, but quantitative experimental validation of this strategy is lacking. Here, we evaluate the role of C–H modes in non-radiative relaxation through isotopic labeling of a NIR-emitting complex. Measurements comparing relaxation between protonated and perdeuterated complexes indicate that C–H modes do not contribute significantly to non-radiative relaxation. We instead propose that skeletal modes may play a larger role and suggest that minimizing scaffold size is a promising route for bright NIR lumiphores. In conclusion, we demonstrate the promise of such strategies through the development of the reddest organic-based laser dye yet reported.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Mechanical and Ionic Characterization for Organic Semiconductor–Incorporated Perovskites for Stable 2D/3D Heterostructure Perovskite Solar Cells

Hybrid metal halide perovskite (MHP) materials, while being promising for photovoltaic technology, also encounter challenges related to material stability. Combining 2D MHPs with 3D MHPs offers a viable solution, yet there is a gap in the understanding of the stability among various 2D materials. The mechanical, ionic, and environmental stability of various 2D MHP ligands are reported, and an improvement with the use of a quater-thiophene-based organic cation (4TmI) that forms an organic-semiconductor incorporated MHP structure is demonstrated. It is shown that the best balance of mechanical robustness, environmental stability, ion activation energy, and reduced mobile ion concentration under accelerated aging is achieved with the usage of 4TmI. It is believed that by addressing mechanical and ion-based degradation modes using this built-in barrier concept with a material system that also shows improvements in charge extraction and device performance, MHP solar devices can be designed for both reliability and efficiency.

14 SOLAR ENERGY↗

Building bases of loop integrands

We describe a systematic approach to the construction of loop-integrand bases at arbitrary loop-order, sufficient for the representation of general quantum field theories. We provide a graph-theoretic definition of ‘power-counting’ for multi-loop integrands beyond the planar limit, and show how this can be used to organize bases according to ultraviolet behavior. This allows amplitude integrands to be constructed iteratively. We illustrate these ideas with concrete applications. In particular, we describe complete integrand bases at two loops sufficient to represent arbitrary-multiplicity amplitudes in four (or fewer) dimensions in any massless quantum field theory with the ultraviolet behavior of the Standard Model or better. We also comment on possible extensions of our framework to arbitrary (including regulated) numbers of dimensions, and to theories with arbitrary mass spectra and charges. At three loops, we describe a basis sufficient to capture all ‘leading-(transcendental-)weight’ contributions of any four-dimensional quantum theory; for maximally supersymmetric Yang-Mills theory, this basis should be sufficient to represent all scattering amplitude integrands in the theory — for generic helicities and arbitrary multiplicity.

1/NExpansion↗