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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 OSTI2021

Inducing thermodynamically blocked atomic ordering via strongly driven nonequilibrium kinetics

Ultrafast light-matter interactions enable inducing exotic material phases by promoting access to kinetic processes blocked in equilibrium. Despite potential opportunities, actively using nonequilibrium kinetics for material discovery is limited by the poor understanding on intermediate states of driven systems. Here, using single-pulse time-resolved imaging with x-ray free-electron lasers, we found intermediate states of photoexcited bismuth nanoparticles that showed kinetically reversed surface ordering during ultrafast melting. This entropy-lowering reaction was further investigated by molecular dynamics simulations to reveal that observed kinetics were thermodynamically buried in equilibrium, which emphasized the critical role of electron-mediated ultrafast free-energy modification in inducing exotic material phases. This study demonstrated that ultrafast photoexcitations of electrons provide an efficient strategy to induce hidden material phases by overcoming thermodynamic barriers via nonequilibrium reaction pathways.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Autonomous discovery of emergent morphologies in directed self-assembly of block copolymer blends

The directed self-assembly (DSA) of block copolymers (BCPs) is a powerful approach to fabricate complex nanostructure arrays, but finding morphologies that emerge with changes in polymer architecture, composition, or assembly constraints remains daunting because of the increased dimensionality of the DSA design space. Here, we demonstrate machine-guided discovery of emergent morphologies from a cylinder/lamellae BCP blend directed by a chemical grating template, conducted without direct human intervention on a synchrotron x-ray scattering beamline. This approach maps the morphology-template phase space in a fraction of the time required by manual characterization and highlights regions deserving more detailed investigation. These studies reveal localized, template-directed partitioning of coexisting lamella- and cylinder-like subdomains at the template period length scale, manifesting as previously unknown morphologies such as aligned alternating subdomains, bilayers, or a “ladder” morphology. This work underscores the pivotal role that autonomous characterization can play in advancing the paradigm of DSA.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2023

Synthesis and functionalization of electron-deficient perfluoroalkyl porphyrin building blocks for supermolecular systems

Synthetic strategies for electron-deficient meso-perfluoroalkylporphyrins bearing diverse functional groups are described. Scalable and efficient syntheses for 5-triisopropylsilylethynyl-10,15,20-tris(heptafluoropropyl)porphyrin and 5-triisopropylsilylethynyl-10,20-bis(heptafluoropropyl)porphyrin that equip meso-ethynyl functional groups via the bilane route have been established, along with a refined route to [5,15-bis(heptafluoropropyl)porphinato]zinc(II). meso-Position halogenation of [5,15-bis(heptafluoropropyl)porphinato]zinc(II) was achieved by selective meso-nitration and subsequent reduction, diazonium salt formation, and iodination reactions. Computational data describe the low energy excited states of these chromophores and the electronic structural factors that control reactivity of these meso-perfluoroalkyl substituted porphyrin complexes. meso-Functionalized [5-triisopropylsilylethynyl-10,20-bis(heptafluoropropyl)porphinato]zinc(II) and [5-iodo-10,20-bis(heptafluoropropyl)porphinato]zinc(II) building blocks lay the foundation for the construction of highly conjugated multiporphyrin arrays that feature electronic structural properties important for the development of n-type materials and high potential photooxidants.

Chemistry↗
DOE OSTI2020

Lithium-Sulfur Batteries with a Block Copolymer Electrolyte Analyzed by X-ray Microtomography

Most of the work on Lithium-sulfur (LiS) batteries use liquid electrolytes that have limited stability when coupled with Li metal anodes. We have studied LiS batteries with a solid block copolymer electrolyte which exhibits improved stability against Li anodes. Additionally, the electrolyte comprises a polystyrene-b-poly(ethylene oxide) (SEO) copolymer doped with a Li salt. Hollow carbon nanospheres impregnated with sulfur were used to build a composite cathode. Two types of sulfur-impregnated functionalized carbon nanospheres were used: One with carboxylic acid groups and the other with short lithium poly(4-styrenesulfonyl(trifluoromethylsulfonyl)imide) (PSTFSI-Li) chains. Cells with Li S dissolved in the SEO based electrolyte served as the baseline. After cycling, the reason for capacity fade was determined by imaging the batteries using synchrotron hard X-ray microtomography. It is generally assumed that LiS cells fail due to dissolution of polysulfide into the liquid electrolyte, i.e., the main problems related to the cathode. In our all-solid cells, failure was primarily due to delamination of the Li foil from the polymer electrolyte layer. Delamination is also observed at the sulfur cathode. It is likely that the large changes in volume of the active materials during cycling induce delamination in all-solid LiS cells. 2 8

25 ENERGY STORAGE↗
DOE OSTI2023

Plating and Stripping of Lithium Metal Stabilized by a Block Copolymer Electrolyte: Local Current Density Measurement and Modeling

Here, plating and stripping of lithium protrusions in lithium metal symmetric cells containing a solid block copolymer electrolyte was studied as a function of time in 3D using time-resolved X-ray tomography. These measurements enabled determination of the spatial variation in current densities at the plating and stripping electrodes. The initial interelectrode distance was 27 μm. Correlation functions were calculated to reveal the relationships between current densities at the two electrodes and local electrolyte thickness. Current densities at opposing electrode locations during protrusion growth is uncorrelated until the local interelectrode distance decreases to less than 6 μm, just before the cell shorts. Mass balance was used to determine the area from which lithium ions that form a protrusion were stripped. Computational modeling of the plating and stripping process reveals the interplay between electrochemical and mechanical driving forces and their effect on nonuniform current distribution. Model predictions were compared with experiments without resorting to any adjustable parameters. The computed correlation functions were in qualitative agreement with experiments. Finally, the model was used to calculate contour plots of electrochemical potential within the electrolyte, shedding light on how geometry, salt concentration, interelectrode distance, and mechanical stress influence local rates of electrochemical reaction.

36 MATERIALS SCIENCE↗
DOE OSTI2020

CSBCOO SPMM: Compressed Sparse Block Coordinate format sparse matrix dense vector multiply benchmark (CSBCOO SPMM) v1.0

The purpose of this microbenchmark is to provide a means to explore different programming methodologies using a simple, but not trivial, mathematical kernel. The kernel is based on the matrix vector product in the MFDn nuclear configuration interaction code's LOBPCG eigensolver. This particular mathematical operation is a key element in the solution of systems of equations and block eigensolvers.

Cook, Brandon↗
DOE OSTI2020

A parallel hierarchical blocked adaptive cross approximation algorithm

This article presents a low-rank decomposition algorithm based on subsampling of matrix entries. The proposed algorithm first computes rank-revealing decompositions of submatrices with a blocked adaptive cross approximation (BACA) algorithm, and then applies a hierarchical merge operation via truncated singular value decompositions (H-BACA). The proposed algorithm significantly improves the convergence of the baseline ACA algorithm and achieves reduced computational complexity compared to the traditional decompositions such as rank-revealing QR. Numerical results demonstrate the efficiency, accuracy, and parallel scalability of the proposed algorithm.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2021

AMReX: Block-structured adaptive mesh refinement for multiphysics applications

Block-structured adaptive mesh refinement (AMR) provides the basis for the temporal and spatial discretization strategy for a number of Exascale Computing Project applications in the areas of accelerator design, additive manufacturing, astrophysics, combustion, cosmology, multiphase flow, and wind plant modeling. AMReX is a software framework that provides a unified infrastructure with the functionality needed for these and other AMR applications to be able to effectively and efficiently utilize machines from laptops to exascale architectures. AMR reduces the computational cost and memory footprint compared to a uniform mesh while preserving accurate descriptions of different physical processes in complex multiphysics algorithms. AMReX supports algorithms that solve systems of partial differential equations in simple or complex geometries and those that use particles and/or particle–mesh operations to represent component physical processes. In this article, we will discuss the core elements of the AMReX framework such as data containers and iterators as well as several specialized operations to meet the needs of the application projects. In addition, we will highlight the strategy that the AMReX team is pursuing to achieve highly performant code across a range of accelerator-based architectures for a variety of different applications.

Zhang, Weiqun↗
DOE OSTI2020

Gas hydrate quantification in Walker Ridge block 313, Gulf of Mexico, from full-waveform inversion of ocean-bottom seismic data

The Gulf of Mexico (GOM) Joint Industry Project Leg 2 logging-while-drilling data in Walker Ridge lease block 313 (WR313) in the GOM detected gas hydrate in coarse- and fine-grained sediments at sites WR313-G and WR313-H. The coarse-grained units are thin ([Formula: see text]) and highly saturated, whereas the fine-grained unit is thick (approximately 200 m) with low saturation and fracture-filling gas hydrate. Unlike its coarse-grained counterpart, the seismic character of the fine-grained unit does not clearly indicate the presence of gas hydrate, which would likely have remained undiscovered in the absence of drilling. In this paper, through frequency-domain acoustic full-waveform inversion (FWI) of ocean-bottom seismometer data along a 2D multichannel seismic transect near sites WR313-G and WR313-H, we detect and quantify gas hydrate in the fine-grained unit. Key results are as follows: First, the base of the gas hydrate stability zone, which is not obvious in the reflection profile, can be discerned in the FWI results. Second, the gas hydrate in the fine-grained unit is mainly confined to the area between two sets of opposite-dipping normal faults implying that the fault architecture may be partially responsible for this gas hydrate accumulation and distribution.

Geochemistry & Geophysics↗
DOE OSTI2021

Las Vegas Block Group Buildings Data

These data include a comprehensive summary of all residential and commercial buildings in the Las Vegas Assessors office dataset as it was on Feb 28th 2021. Building level data has been summarized to the US Census 2020 Block Group geographies.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2024

TEAMER: Drifting Hydrophone System - Block Diagram and Pre-Amplifier Calibrations

This data release is part of TEAMER RFTS 2, where the Cooperative Institute for Marine Resources Studies (CIMRS) at Oregon State University is performing hardware and software development and integration of four newly designed drifting hydrophone systems for underwater noise measurements at marine renewable energy projects. These new acoustic systems will provide advanced technology support available for use at both tidal and wave energy deployments adding additional resources to the limited amount of drifting hydrophone technologies that are available to the marine energy community The submission data contains 2 files plus a Post-Access Report: One file containing the calibration parameters for four (4) pre-amplifier boards used on the drifting hydrophones. Pre-amplifier boards are model "WB PREAMP REV6," with serial numbers; 28, 29, 30, and 31. One image file illustrating the system functional block diagram of the drifting hydrophone system configuration.

16 TIDAL AND WAVE POWER↗
DOE OSTI2025

Directed self-assembly of block copolymers for high-precision patterning in the era of extreme ultraviolet lithography

Extreme ultraviolet (EUV) lithography enables unprecedented resolution in semiconductor patterning but faces critical challenges in developing resist materials that achieve high-precision at economically viable throughput. Directed self-assembly (DSA) of block copolymers (BCPs) offers a promising solution for pattern rectification by leveraging thermodynamically determined domain structures to decouple BCP pattern quality from the imperfect original lithographic pattern. This prospective presents an overview of recent progress on the EUV + DSA strategy, covering advances in BCP material design, processing, metrology, and pattern transfer. We highlight recent advances in high-χ BCPs with perpendicular orientation and domain spacings compatible with EUV dimensions, leveraging A-b-(B-r-C) architectures. We also discuss progress in chemical pre-pattern fabrication using both positive- and negative tone resists, along with processing strategies to minimize defects and roughness based on BCP thermodynamics and assembly kinetics. We further examine metrology platforms for characterizing the thermodynamics of BCP materials and quantifying the size and shape of BCP domains. Lastly, we review pattern transfer strategies for generating functional inorganic masks suitable for semiconductor manufacturing. Together, these advances highlight the potential of DSA to complement EUV lithography, offering a pathway to address critical challenges in achieving high-precision patterning for the semiconductor industry.

Lee, Kyunghyeon [Univ. of Chicago, IL (United Stat↗
DOE OSTI2023

Small Business Voucher Program: Scaling-Up of Bio-Based C5 Building Block Production: Cooperative Research and Development Final Report, CRADA Number CRD-16-00611

Visolis, Inc. is an early stage industrial biotechnology company developing next generation of processes for producing building blocks for bulk polymers and fuels. The company is developing low-cost routes to the chemicals of the future in support of DOE, EERE and BETO goals to grow the U.S. bioeconomy. NREL has capabilities in scale-up of fermentation processes from bench top through pilot scales and also has expertise and technologies related to production of lignocellulosic sugars from cellulosic feedstocks. NREL's Integrated Biorefinery Research Facility (IBRF) houses multiple fermentation vessels/systems ranging in size from 0.5 to 9,000 L along with ancillary capabilities in compositional analysis, separations, and purification. NREL's role will be to scale-up the Visolis process to produce an intermediate product, mevalonic acid, from both dextrose and biomass derived sugars. The goals of the project are to: 1) transfer and reproduce one of Visolis's proprietary fermentation processes at bench top and pilot scale at NREL's IBRF using dextrose as the feedstock, 2) carry out bench-scale fermentations using Visolis's organism and cellulosic sugars, and 3) produce mevalonic acid from the bench top and pilot scale runs for catalyst lifetime testing and conversion to isoprene.

09 BIOMASS FUELS↗
DOE OSTI2020

Development of lithium ion conducting interface between lithium metal and a lithium ion conducting ceramic using block polymers

The lithium-air (Li-air) technology developed by EDF uses an air electrode which works with an aqueous electrolyte, which prevent the use of unprotected lithium metal electrode. A Li+ ionic conductor glass ceramic is used to separate the aqueous electrolyte compartment from the negative lithium electrode. However, this glass-ceramic is not stable in contact with lithium, it is thus necessary to add a protective buffer layer. In another hand, this protection should ideally resist to lithium dendritic growth. It is in this context that this research project which has as goal the development of a protective buffer layer based on block copolymer electrolytes (BCE) between the lithium metal and the lithium ionic conductor ceramic, for lithium-air battery. In a first part, the BCE is studied in lithium-lithium symmetric cells, in order to determine their electrochemical properties such as ionic conductivity, steady state transference number, and finally their resistance to dendritic growth during cycling. Several characterization techniques were employed and especially hard X-ray micro-tomography to analyze the lithium morphology before and after cycling. For single-ion BCE, we expect to suppress dendritic growth, however, we report here for the first time, the visualization of a homogeneous growth of lithium but the formation of dense lithium objects. In another part, the composite BCE-ceramic is studied by electrochemical impedance spectroscopy (EIS). The cycling of lithium-composite-lithium symmetric cells and the analysis of the EIS measurement after each cycle permit to determine if the dendrites have cross the protective layer and are in contact with the ceramic. Besides, the quantification of the polarization loss at the interface polymer-ceramic is evaluated by polarization experiments. This contribution is found to be small.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Site 200 #1400 Block Area New Trailers Project, Soil Sampling and Analysis Plan/Quality Assurance Plan

Lawrence Livermore National Laboratory's (LLNL) Project Management Office (PMO) is proposing to install a series of modular trailers and install associated underground utilities in the 1400 Block at the Livermore Site. This Sampling and Analysis Plan (SAP) outlines the processes and procedures to collect environmental and geotechnical soil samples from the project area and to send the samples to the appropriate laboratory or laboratories for analysis or testing. The resulting environmental laboratory data will determine whether excavated soils can be reused on the project, or which type of landfill or landfills the soils may be sent for disposal. This SAP has been prepared and is organized to be consistent with LLNL's Soils Screening and Management Plan (SSMP) (LLNL, 2019), as well as the U.S. Environmental Protection Agency's (EPA) Data Quality Objectives programs (EPA, 2006).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Data Report: X-Ray Diffraction of Sediments from Green Canyon Block 955, Gulf of Mexico

We performed 18 X-ray diffraction (XRD) measurements on sediment samples acquired at Holes H002 (6 samples) and H005 (12 samples) during the UT-GOM2-1 Expedition in Green Canyon Block 955, in the northern Gulf of Mexico. Results indicate a predominance of quartz, with significant proportions of alkali feldspar and carbonate, and minor amounts of amphibole, micas, and clays.

03 NATURAL GAS↗
DOE OSTI2020

Data Report: High-Resolution Microscopy Images of Sediments from Green Canyon Block 955, Gulf of Mexico

We took Leica microscopy images of sediment samples acquired at Holes H002 (4 samples) and H005 (1 sample) during the UT-GOM2-1 Expedition in Green Canyon Block 955, in the northern Gulf of Mexico. A total of 37 images were acquired. The images document a prevalence of spherical conchoidal minerals, cleavage planes typical of feldspar or mica, and black fragmented minerals which stand out from the surrounding matrix. Drilling mud intrusion is thought to contribute to a grey metallic matrix observed across multiple samples.

03 NATURAL GAS↗
DOE OSTI2020

Building Blocks from Biocrude: High-Value Methoxyphenols (Final Scientific/Technical Report)

Integrating biofuels production with bioproducts presents an opportunity to explore options for recovering high-value chemicals as additional revenue-generating products from biofuel conversion pathways. Thus, the overall objective of this project was to develop a comprehensive separation strategy to economically recover valuable methoxyphenols (MPs) consisting of guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-propylguaiacol, eugenol, and isoeugenol from biocrude as building blocks to demonstrate that bioproducts could enable cost-effective production of biofuels via integrated catalytic pyrolysis and hydroprocessing. The upgradability of the remaining biocrude fraction to biofuel after separation of the products was evaluated by hydrotreating. Finally, techno-economic analysis (TEA) was performed to examine the economic potential of recovering select MPs from biocrude in parallel with biofuels production.

09 BIOMASS FUELS↗