2,444 results match your criteria: "WA 99352; ‡Heinrich Heine University[Affiliation]"

Atom probe tomography (APT) has been utilized to investigate the microstructure of two model borosilicate glasses designed to understand the solubility limits of phosphorous pentoxide (P2O5). This component is found in certain high-level radioactive defence wastes destined for vitrification, where phase separation can potentially lead to a number of issues relating to the processing of the glass and its long-term chemical and structural stability. The development of suitable focused ion beam (FIB)-preparation routes and APT analysis conditions were initially determined for the model glasses, before examining their detailed microstructures.

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Quantifying local and global mass balance errors in physics-informed neural networks.

Sci Rep

July 2024

Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.

Physics-informed neural networks (PINN) have recently become attractive for solving partial differential equations (PDEs) that describe physics laws. By including PDE-based loss functions, physics laws such as mass balance are enforced softly in PINN. This paper investigates how mass balance constraints are satisfied when PINN is used to solve the resulting PDEs.

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Investigation of Fe-Ni Battery/Module for Grid Service Duty Cycles.

Materials (Basel)

June 2024

Battery Materials & System Group, Pacific Northwest National Laboratory, Richland, WA 99352, USA.

Iron-nickel (Fe-Ni) batteries are renowned for their durability and resilience against overcharging and operating temperatures. However, they encounter challenges in achieving widespread adoption for energy storage applications due to their low efficiency and the need for regular maintenance and electrolyte replacement, which adds to maintenance costs. This study evaluates and demonstrates the capabilities of Fe-Ni batteries for participating in grid energy storage applications.

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Article Synopsis
  • The study analyzes the characteristics of ultrathin films made of 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) using advanced techniques like tip-enhanced photoluminescence and machine learning.
  • Researchers uncover nanoscale variations in the films' spectra, which are influenced by interactions among vibrational effects and excitons (both intermolecular and intramolecular).
  • The findings help deepen the understanding of how these interactions affect the properties of PTCDI films at the nanoscale.
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  • The detection and cleanup of per- and polyfluoroalkyl substances (PFAS) is increasingly important due to their environmental contamination.
  • Researchers are exploring low-temperature thermal treatment (200-500 °C) for PFAS, which requires less energy and infrastructure, but the byproducts of this process are not well understood.
  • Using gas-phase infrared spectroscopy and multivariate curve resolution analysis, the study identifies and quantifies nine decomposition products from the thermal breakdown of potassium perfluorooctanesulfonate (PFOS-K) starting at 375 °C.
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We demonstrate that active site ensembles on transition metal phosphides tune the selectivity of the nitrate reduction reaction. Using NiP nanocrystals as a case study, we report a mechanism involving competitive co-adsorption of H* and NO* intermediates. A near 100% faradaic efficiency for nitrate reduction over hydrogen evolution is observed at -0.

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Electrochemical Imaging of Precisely-Defined Redox and Reactive Interfaces.

Angew Chem Int Ed Engl

September 2024

Pacific Northwest National Laboratory, Richland, WA 99352, USA.

Understanding the diverse electrochemical reactions occurring at electrode-electrolyte interfaces (EEIs) is a critical challenge to developing more efficient energy conversion and storage technologies. Establishing a predictive molecular-level understanding of solid electrolyte interphases (SEIs) is challenging due to the presence of multiple intertwined chemical and electrochemical processes occurring at battery electrodes. Similarly, chemical conversions in reactive electrochemical systems are often influenced by the heterogeneous distribution of active sites, surface defects, and catalyst particle sizes.

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Mechanistic understanding of speciated oxide growth in high entropy alloys.

Nat Commun

June 2024

Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.

Complex multi-element alloys are gaining prominence for structural applications, supplementing steels, and superalloys. Understanding the impact of each element on alloy surfaces due to oxidation is vital in maintaining material integrity. This study investigates oxidation mechanisms in these alloys using a model five-element equiatomic CoCrFeNiMn alloy, in a controlled oxygen environment.

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Deep learning with mixup augmentation for improved pore detection during additive manufacturing.

Sci Rep

June 2024

Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.

In additive manufacturing (AM), process defects such as keyhole pores are difficult to anticipate, affecting the quality and integrity of the AM-produced materials. Hence, considerable efforts have aimed to predict these process defects by training machine learning (ML) models using passive measurements such as acoustic emissions. This work considered a dataset in which keyhole pores of a laser powder bed fusion (LPBF) experiment were identified using X-ray radiography and then registered both in space and time to acoustic measurements recorded during the LPBF experiment.

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Article Synopsis
  • The efficient upgrading of biomass-derived oxygenates into fuels and chemicals requires selective C-C bond formation and effective oxygen removal.
  • Co-feeding water can aid catalytic reactions, but a recent study utilized a CeSnBeta catalyst with dual Lewis acidic sites to generate isobutene from acetone without needing water.
  • By incorporating cerium into a modified SnBeta framework, researchers achieved stable and selective catalysis for acetone-to-isobutene conversions, highlighting the advantages of this confined dual site approach.
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Demonstration of event position reconstruction based on diffusion in the NEXT-white detector.

Eur Phys J C Part Fields

May 2024

Department of Physics and Astronomy, Texas A &M University, College Station, TX 77843-4242 USA.

Noble element time projection chambers are a leading technology for rare event detection in physics, such as for dark matter and neutrinoless double beta decay searches. Time projection chambers typically assign event position in the drift direction using the relative timing of prompt scintillation and delayed charge collection signals, allowing for reconstruction of an absolute position in the drift direction. In this paper, alternate methods for assigning event drift distance via quantification of electron diffusion in a pure high pressure xenon gas time projection chamber are explored.

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Separation of gold from irradiated actinide material utilizing a 2- thenoyltrifluoroacetone extraction resin.

J Chromatogr A

July 2024

Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA 99352, USA.

Post-detonation nuclear forensics capabilities depend on the ability to rapidly isolate radionuclides to improve measurement quality. In this work an extraction chromatography resin was developed utilizing thenoyltrifluoroacetone and 1-octanol supported on Eichrom prefilter resin. The resin was tested in nitric and hydrochloric acid matrices.

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Evaluation of methods for characterizing the fine particulate matter emissions from aircraft and other diffusion flame combustion aerosol sources.

J Aerosol Sci

May 2024

U. S. Environmental Protection Agency, Office of Transportation and Air Quality, National Vehicle and Fuels Emissions Laboratory, Ann Arbor, MI, 48105, USA.

The U. S. Environmental Protection Agency in collaboration with the U.

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Fluoro-Ethylene-Carbonate Plays a Double-Edged Role on the Stability of Si Anode-Based Rechargeable Batteries During Cycling and Calendar Aging.

Adv Mater

July 2024

Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.

The energy storage density of Li-ion batteries can be improved by replacing graphite anodes with high-capacity Si-based materials, though instabilities have limited their implementation. Performance degradation mechanisms that occur in Si anodes can be divided into cycling stability (capacity retention after repeated battery cycles) and calendar aging (shelf life). While cycling instabilities and improvement strategies have been researched intensively, there is little known about the underlying mechanisms that cause calendar aging.

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Motivation: MerCat2 ("Mer-Catenate2") is a versatile, parallel, scalable and modular property software package for robustly analyzing features in omics data. Using massively parallel sequencing raw reads, assembled contigs, and protein sequences from any platform as input, MerCat2 performs -mer counting of any length , resulting in feature abundance counts tables, quality control reports, protein feature metrics, and graphical representation (i.e.

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A new method for quantifying Cu in nuclear debris samples.

Talanta

August 2024

Nuclear and Radiochemistry (C-NR), Los Alamos National Laboratory, Mail Stop J-514, Los Alamos, NM, 87545, USA. Electronic address:

Quantifying Cu in post-detonation nuclear debris samples can provide important diagnostic information regarding the structural materials used within a nuclear device. However, this task is challenging due to the weak gamma emissions associated with the decay of Cu, its short half-life (12.701 h), and the presence of interfering fission product radioisotopes.

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Ionic Pairs-Engineered Fluorinated Covalent Organic Frameworks Toward Direct Air Capture of CO.

Small

September 2024

Department of Chemistry, Institute for Advanced Materials and Manufacturing, University of Tennessee, Knoxville, TN, 37996, USA.

Article Synopsis
  • Researchers have developed a new type of covalent organic framework (COF) called F-COF that captures low concentrations of carbon monoxide (CO) from air.
  • This framework maintains its crystalline structure while incorporating basic fluorinated alcoholate anions, enabling efficient CO capture through O─C bond formation.
  • The F-COF demonstrates promising performance with less energy required for CO release, offering potential advantages over traditional amine-derived carbon capture materials.
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Article Synopsis
  • Evaluating the hazards of environmental chemical mixtures, specifically polycyclic aromatic hydrocarbons (PAHs), is a major challenge in human health risk assessment, especially regarding their effects on lung cells.* -
  • The study created two synthetic PAH mixtures based on samples from a legacy creosote site and tested their impact on human bronchial epithelial cells, focusing on various toxicological biomarkers.* -
  • Results indicated that existing models underestimated toxicity and suggested that PAH interactions might be non-additive, highlighting the need for improved methods in assessing mixture toxicity in environmental samples.*
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A long-standing challenge in bioinspired materials is to design and synthesize synthetic materials that mimic the sophisticated structures and functions of natural biomaterials, such as helical protein assemblies that are important in biological systems. Herein, we report the formation of a series of nanohelices from a type of well-developed protein-mimetics called peptoids. We demonstrate that nanohelix structures and supramolecular chirality can be well-controlled through the side-chain chemistry.

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Preparation of monodisperse cerium oxide particle suspensions from a tetravalent precursor.

Dalton Trans

April 2024

Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.

Cerium oxide particles are a unique material that enables studying the intersection of metal oxides, -elements, and nanomaterials. Distinct from diverse applications in catalysis, energy, and medicine, cerium possesses additional influence as a non-radioactive actinide surrogate. Herein, we present a synthesis for sub-micron cerium particles using hexamethylenetetramine and ammonium hydroxide as precipitating agents with a Ce precursor.

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Twinning, on par with dislocations, is critically required in plastic deformation of hexagonal close-packed crystals at low temperatures. In contrast to that in cubic-structured crystals, twinning in hexagonal close-packed crystals requires atomic shuffles in addition to shear. Though the twinning shear that is carried by twinning dislocations has been captured for decades, direct experimental observation of the atomic shuffles, especially when the shuffling mode is not unique and does not confine to the plane of shear, remains a formidable challenge to date.

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A compendium of multi-omics data illuminating host responses to lethal human virus infections.

Sci Data

April 2024

Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.

Human infections caused by viral pathogens trigger a complex gamut of host responses that limit disease, resolve infection, generate immunity, and contribute to severe disease or death. Here, we present experimental methods and multi-omics data capture approaches representing the global host response to infection generated from 45 individual experiments involving human viruses from the Orthomyxoviridae, Filoviridae, Flaviviridae, and Coronaviridae families. Analogous experimental designs were implemented across human or mouse host model systems, longitudinal samples were collected over defined time courses, and global multi-omics data (transcriptomics, proteomics, metabolomics, and lipidomics) were acquired by microarray, RNA sequencing, or mass spectrometry analyses.

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Monoterpene synthases (MTSs) catalyze the first committed step in the biosynthesis of monoterpenoids, a class of specialized metabolites with particularly high chemical diversity in angiosperms. In addition to accomplishing a rate enhancement, these enzymes manage the formation and turnover of highly reactive carbocation intermediates formed from a prenyl diphosphate substrate. At each step along the reaction path, a cationic intermediate can be subject to cyclization, migration of a proton, hydride, or alkyl group, or quenching to terminate the sequence.

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Classical vs. quantum plasmon-induced molecular transformations at metallic nanojunctions.

Proc Natl Acad Sci U S A

April 2024

Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352.

Chemical transformations near plasmonic metals have attracted increasing attention in the past few years. Specifically, reactions occurring within plasmonic nanojunctions that can be detected via surface and tip-enhanced Raman (SER and TER) scattering were the focus of numerous reports. In this context, even though the transition between localized and nonlocal (quantum) plasmons at nanojunctions is documented, its implications on plasmonic chemistry remain poorly understood.

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While polyphenol consumption is often associated with an increased abundance of beneficial microbes and decreased opportunistic pathogens, these relationships are not completely described for polyphenols consumed via habitual diet, including culinary herb and spice consumption. This analysis of the International Cohort on Lifestyle Determinants of Health (INCLD Health) cohort uses a dietary questionnaire and 16s microbiome data to examine relationships between habitual polyphenol consumption and gut microbiota in healthy adults (n = 96). In this exploratory analysis, microbial taxa, but not diversity measures, differed by levels of dietary polyphenol consumption.

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