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DOE OSTI2026

Critical Review of Brazil Disk Techniques for Tensile Strength Characterization With an Emphasis on High Explosive Materials

Mechanical properties are a critical performance metric for many high explosive (HE) materials and tensile strength properties are particularly important. Direct tensile measurements using dogbone shaped samples are the gold standard but they have the disadvantage that they are fairly large and require samples machined from billets. Diametral compression, more commonly known as Brazil disk (BD) testing, is an indirect method for measuring tensile strength on smaller and more easily fabricated samples. A review of the BD literature is presented with an emphasis on tensile strength measurements in high explosive materials. BD literature is reviewed in three primary areas: (i) rocks and concrete, (ii) pharmaceutical materials, and (iii) high explosive materials. The literature for rocks/concrete is extensive and dates back over 80 years; despite this there is no consensus on the validity/accuracy of the BD technique or the optimal variant of the BD technique to employ. The pharmaceutical literature is the opposite, being limited in scope and quantity of studies. BD literature on high explosive materials falls in between, not as impressive as in the rocks/concrete community but more substantiative than in the pharmaceutical community. After the review of the literature practical parameters for HE BD testing and recommended future work is discussed.

Brazil disk↗

DOE OSTI2017

Automated single-ion peak fitting as an efficient approach for analyzing complex chromatographic data

Chromatography provides important detail on the composition of environmental samples and their chemical processing. However, the complexity of these samples and their tendency to contain many structurally and chemically similar compounds frequently results in convoluted or poorly resolved data. Data reduction from raw chromatograms of complex environmental data into integrated peak areas consequently often requires substantial operator interaction. This difficulty has led to a bottleneck in analysis that increases analysis time, decreases data quality, and will worsen as advances in field-based instrumentation multiply the quantity and informational density of data produced. In this work, we develop and validate an automated approach to fitting chromatographic data within a target retention time window with a combination of multiple idealized peaks (Gaussian peaks either with or without an exponential decay component). Herein we compare this single-ion peak fitting approach to drawn baseline integration methods of more than 70,000 peaks collected by field-based chromatographs spanning across a wide range of volatilities and functionalities. Accuracy of peak fitting under real-world conditions is found to be within 10%. The quantitative parameters describing the fit (e.g. coefficients, fit residuals, etc.) are found to provide valuable information to increase the efficiency of quality control and provide constraints to accurately integrate peaks that are significantly convoluted with neighboring peaks. Implementation of the peak fitting method is shown to yield accurate integration of peaks otherwise too poorly resolved to separate into individual compounds and improved quantitative metrics to determine the fidelity of the data reduction process, while substantially decreasing the time spent by operators on data reduction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2023

Efficacy of antivirals and mRNA vaccination against an XBF clinical isolate

Recombination events occur frequently in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulting in genetic diversity. Because these events contribute to altered host immune evasion and antiviral susceptibility, it is crucial to evaluate the efficacy of COVID-19 vaccines and antivirals against recombinant variants. As of March 2023, XBB.1.5, a recombinant sublineage of XBB, is currently the dominant form globally (Fig. S1A, Supplementary Appendix). XBB emerged as a result of recombination between two BA.2 descendants, BJ.1 and BM.1.1.1 (a progeny of BA.2.75). We and other groups have shown that XBB.1.5 is resistant to several therapeutic monoclonal antibodies and effectively evades humoral immunity elicited by natural infection or COVID-19 vaccination.1, 2, 3 By March 30, 2023, an additional recombinant variant, XBF, had been sampled 8966 times in 47 countries and territories in GISAID, reaching it highest prevalence in Australia and New Zealand (Fig. S2, Supplementary Appendix). XBF is still increasing in frequency, although the prevalence of XBB.1.5 appears to be increasing at a faster pace in most regions (Fig. S1B, Supplementary Appendix). XBF is a recombinant of BA.5.2.3 (a descendant of BA.5) and CJ.1 (a descendant of BA.2.75) and, like CJ.1, has an additional three substitutions (R346T, F486P, and F490S) in the receptor-binding domain (RBD) of the consensus form of its spike protein compared to baseline BA.2.75 (Fig. S3A, Supplementary Appendix). CJ.1 and its related sublineage CJ.1.1 did not expand as extensively as XBF, being sampled in GISAID only 1589 and 142 times respectively. CJ.1 was found circulating in many countries, but most commonly sampled in South Korea, where it is still increasing and has currently reached about 5% of the sampled population. CJ.1.1 was most frequently sampled in Malaysia and Singapore, but remained rare in both nations, peaking at about 1% of the sample in December of 2022. Despite the importance of these related variants, we have no information about the antiviral efficacy and immunity induced by COVID-19 vaccines against a clinical isolate of XBF.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2016

Atomic structure and defect energetics of LiCoO{sub 2} grain boundary

Highlights: • We model the sample grain boundary of LiCoO2, one of important Li cathode materials. • Rigid body translation was found the asymmetric GB is more stable than symmetric GB. • The vacancy formation energy of Li and O was estimated with first principles calculations. • This model boundary can help to find a new dopant to improve Li diffusions. - Abstract: An atomic structure of LiCoO{sub 2} model grain boundary, Σ2 [1120](1102), is introduced and grain boundary energies with rigid body translations are investigated systematically to find the most stable interface structures. It is found that the coordinated structures of Co and O in the vicinity of grain boundary are strongly related to grain boundary energy. Examining nonstoichiometry at grain boundary, the defect energetics of Li and O site at grain boundary are estimated. In addition, the effect of grain boundary on Li diffusion is investigated to calculate Li diffusion across grain boundary.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Origins of Photoluminescence Instabilities at Halide Perovskite/Organic Hole Transport Layer Interfaces

Metal halide perovskites are promising for optoelectronic device applications; however, their poor stability under solar illumination remains a primary concern. While the intrinsic photostability of isolated neat perovskite samples has been widely discussed, it is important to explore how charge transport layers—employed in most devices—impact photostability. Here, in this paper, we study the effect of organic hole transport layers (HTLs) on light-induced halide segregation and photoluminescence (PL) quenching at perovskite/organic HTL interfaces. By employing a series of organic HTLs, we demonstrate that the HTL’s highest occupied molecular orbital energy dictates behavior; furthermore, we reveal the key role of halogen loss from the perovskite and subsequent permeation into organic HTLs, where it acts as a PL quencher at the interface and introduces additional mass transport pathways to facilitate halide phase separation. In doing so, we both reveal the microscopic mechanism of non-radiative recombination at perovskite/organic HTL interfaces and detail the chemical rationale for closely matching the perovskite/organic HTL energetics to maximize solar cell efficiency and stability.

14 SOLAR ENERGY↗

DOE OSTI2019

A five-level classification system for proteoform identifications

The term proteoform, introduced in these pages in 2013, has rapidly gained acceptance in the proteomics community. The challenge and importance of comprehensively identifying proteoforms in complex samples has been recognized, and reports have begun to appear of new platforms towards that end. However, one interesting central ambiguity has emerged, namely determining precisely what is meant by a “proteoform identification”. At present, the only practical approaches for establishing the exact primary structure of a proteoform employ mass spectrometry (MS), and there is a wide range of MS results that provide “proteoform identifications”. This seemingly small matter has significant impact, as the ambiguity in knowing what is meant by an “identification” makes it difficult to compare results from different laboratories and approaches. This situation hinders the ability of the community to evaluate technological progress and to efficiently expand biological knowledge. To address this issue, we propose a five-level system for classifying proteoform identifications. Here, the classification scheme stems directly from a consideration of the four types of possible ambiguity possible for a proteoform identification, ranging from the most subtle (i.e., precise localization of a post-translational modification, or PTM) to the most dramatic (i.e., ambiguity in the gene of origin). The five classes then correspond to the level of ambiguity present in the identification, ranging from no ambiguity at all (Level 1), to ambiguity of all four types (Level 5). Details of the scheme are provided in Table 1 and Supplementary Table 1, with specific use cases and examples provided in Supplementary Figure 1.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2023

MArVD2: a machine learning enhanced tool to discriminate between archaeal and bacterial viruses in viral datasets

Abstract Our knowledge of viral sequence space has exploded with advancing sequencing technologies and large-scale sampling and analytical efforts. Though archaea are important and abundant prokaryotes in many systems, our knowledge of archaeal viruses outside of extreme environments is limited. This largely stems from the lack of a robust, high-throughput, and systematic way to distinguish between bacterial and archaeal viruses in datasets of curated viruses. Here we upgrade our prior text-based tool (MArVD) via training and testing a random forest machine learning algorithm against a newly curated dataset of archaeal viruses. After optimization, MArVD2 presented a significant improvement over its predecessor in terms of scalability, usability, and flexibility, and will allow user-defined custom training datasets as archaeal virus discovery progresses. Benchmarking showed that a model trained with viral sequences from the hypersaline, marine, and hot spring environments correctly classified 85% of the archaeal viruses with a false detection rate below 2% using a random forest prediction threshold of 80% in a separate benchmarking dataset from the same habitats.

Vik, Dean (ORCID:000000027546899X)↗

DOE OSTI2017

Significant improvement in Mn 2 O 3 transition metal oxide electrical conductivity via high pressure

ighly efficient energy storage is in high demand for next-generation clean energy applications. As a promising energy storage material, the application of Mn 2 O 3 is limited due to its poor electrical conductivity. Here, high-pressure techniques enhanced the electrical conductivity of Mn 2 O 3 significantly. In situ synchrotron micro X-Ray diffraction, Raman spectroscopy and resistivity measurement revealed that resistivity decreased with pressure and dramatically dropped near the phase transition. At the highest pressure, resistivity reduced by five orders of magnitude and the sample showed metal-like behavior. More importantly, resistivity remained much lower than its original value, even when the pressure was fully released. This work provides a new method to enhance the electronic properties of Mn 2 O 3 using high-pressure treatment, benefiting its applications in energy-related fields.

Science & Technology - Other Topics↗

DOE OSTI2024

Broad absorption line quasars in the Dark Energy Spectroscopic Instrument Early Data Release

Broad absorption line (BAL) quasars are characterized by gas clouds that absorb flux at the wavelength of common quasar spectral features, although blueshifted by velocities that can exceed $0.1c$. BAL features are interesting as signatures of significant feedback, yet they can also compromise cosmological studies with quasars by distorting the shape of the most prominent quasar emission lines, impacting redshift accuracy and measurements of the matter density distribution traced by the Lyman $\alpha$ forest. We present a catalogue of BAL quasars discovered in the Dark Energy Spectroscopic Instrument (DESI) survey Early Data Release, which were observed as part of DESI Survey Validation, as well as the first two months of the main survey. We describe our method to automatically identify BAL quasars in DESI data, the quantities we measure for each BAL, and investigate the completeness and purity of this method with mock DESI observations. We mask the wavelengths of the BAL features and re-evaluate each BAL quasar redshift, finding new redshifts which are $243\, {\rm km}\, {\rm s}^{-1}$ smaller on average for the BAL quasar sample. These new, more accurate redshifts are important to obtain the best measurements of quasar clustering, especially at small scales. Finally, we present some spectra of rarer classes of BALs that illustrate the potential of DESI data to identify such populations for further study.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2022

Mass spectrometry-based technologies for probing the 3D world of plant proteins

Abstract Over the past two decades, mass spectrometric (MS)-based proteomics technologies have facilitated the study of signaling pathways throughout biology. Nowhere is this needed more than in plants, where an evolutionary history of genome duplications has resulted in large gene families involved in posttranslational modifications and regulatory pathways. For example, at least 5% of the Arabidopsis thaliana genome (ca. 1,200 genes) encodes protein kinases and protein phosphatases that regulate nearly all aspects of plant growth and development. MS-based technologies that quantify covalent changes in the side-chain of amino acids are critically important, but they only address one piece of the puzzle. A more crucially important mechanistic question is how noncovalent interactions—which are more difficult to study—dynamically regulate the proteome’s 3D structure. The advent of improvements in protein 3D technologies such as cryo-electron microscopy, nuclear magnetic resonance, and X-ray crystallography has allowed considerable progress to be made at this level, but these methods are typically limited to analyzing proteins, which can be expressed and purified in milligram quantities. Newly emerging MS-based technologies have recently been developed for studying the 3D structure of proteins. Importantly, these methods do not require protein samples to be purified and require smaller amounts of sample, opening the wider proteome for structural analysis in complex mixtures, crude lysates, and even in intact cells. These MS-based methods include covalent labeling, crosslinking, thermal proteome profiling, and limited proteolysis, all of which can be leveraged by established MS workflows, as well as newly emerging methods capable of analyzing intact macromolecules and the complexes they form. In this review, we discuss these recent innovations in MS-based “structural” proteomics to provide readers with an understanding of the opportunities they offer and the remaining challenges for understanding the molecular underpinnings of plant structure and function.

Plant Sciences↗

DOE OSTI2017

r -process nucleosynthesis from matter ejected in binary neutron star mergers [On r -process nucleosynthesis from matter ejected in binary neutron star mergers]

Here, when binary systems of neutron stars merge, a very small fraction of their rest mass is ejected, either dynamically or secularly. This material is neutron-rich and its nucleosynthesis provides the astrophysical site for the production of heavy elements in the Universe, together with a kilonova signal confirming neutron-star mergers as the origin of short gamma-ray bursts. We perform full general-relativistic simulations of binary neutron-star mergers employing three different nuclear-physics equations of state (EOSs), considering both equal- and unequal-mass configurations, and adopting a leakage scheme to account for neutrino radiative losses. Using a combination of techniques, we carry out an extensive and systematic study of the hydrodynamical, thermodynamical, and geometrical properties of the matter ejected dynamically, employing the WinNet nuclear-reaction network to recover the relative abundances of heavy elements produced by each configurations. Among the results obtained, three are particularly important. First, we find that, within the sample considered here, both the properties of the dynamical ejecta and the nucleosynthesis yields are robust against variations of the EOS and masses. Second, using a conservative but robust criterion for unbound matter, we find that the amount of ejected mass is ≲10 –3 M⊙, hence at least one order of magnitude smaller than what normally assumed in modelling kilonova signals. Finally, using a simplified and gray-opacity model we assess the observability of the infrared kilonova emission finding, that for all binaries the luminosity peaks around ~1/2 day in the H-band, reaching a maximum magnitude of –13, and decreasing rapidly after one day.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2016

Characterization of the shape and line-edge roughness of polymer gratings with grazing incidence small-angle X-ray scattering and atomic force microscopy

Grazing-incidence small-angle X-ray scattering (GISAXS) is increasingly used for the metrology of substrate-supported nanoscale features and nanostructured films. In the case of line gratings, where long objects are arranged with a nanoscale periodicity perpendicular to the beam, a series of characteristic spots of high-intensity (grating truncation rods, GTRs) are recorded on a two-dimensional detector. The intensity of the GTRs is modulated by the three-dimensional shape and arrangement of the lines. Previous studies aimed to extract an average cross-sectional profile of the gratings, attributing intensity loss at GTRs to sample imperfections. Such imperfections are just as important as the average shape when employing soft polymer gratings which display significant line-edge roughness. Herein are reported a series of GISAXS measurements of polymer line gratings over a range of incident angles. Both an average shape and fluctuations contributing to the intensity in between the GTRs are extracted. Lastly, the results are critically compared with atomic force microscopy (AFM) measurements, and it is found that the two methods are in good agreement if appropriate corrections for scattering from the substrate (GISAXS) and contributions from the probe shape (AFM) are accounted for.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Changes in geophysical properties caused by fluid injection into porous rocks: analytical models: Geophysical changes in porous rocks

Analytical models are provided that describe how the elastic compliance, electrical conductivity, and fluid-flow permeability of rocks depend on stress and fluid pressure. In order to explain published laboratory data on how seismic velocities and electrical conductivity vary in sandstones and granites, the models require a population of cracks to be present in a possibly porous host phase. The central objective is to obtain a consistent mean-field analytical model that shows how each modeled rock property depends on the nature of the crack population. We describe the crack populations by a crack density, a probability distribution for the crack apertures and radii, and the averaged orientation of the cracks. The possibly anisotropic nature of the elasticity, conductivity, and permeability tensors is allowed for; however, only the isotropic limit is used when comparing to laboratory data. For the transport properties of conductivity and permeability, the percolation effect of the crack population linking up to form a connected path across a sample is modeled. But, this effect is important only in crystalline rock where the host phase has very small conductivity and permeability. In general, the importance of the crack population to the transport properties increases as the host phase becomes less conductive and less permeable.

58 GEOSCIENCES↗

DOE OSTI2019

A Novel Sparse Compositional Technique Reveals Microbial Perturbations

ABSTRACT The central aims of many host or environmental microbiome studies are to elucidate factors associated with microbial community compositions and to relate microbial features to outcomes. However, these aims are often complicated by difficulties stemming from high-dimensionality, non-normality, sparsity, and the compositional nature of microbiome data sets. A key tool in microbiome analysis is beta diversity, defined by the distances between microbial samples. Many different distance metrics have been proposed, all with varying discriminatory power on data with differing characteristics. Here, we propose a compositional beta diversity metric rooted in a centered log-ratio transformation and matrix completion called robust Aitchison PCA. We demonstrate the benefits of compositional transformations upstream of beta diversity calculations through simulations. Additionally, we demonstrate improved effect size, classification accuracy, and robustness to sequencing depth over the current methods on several decreased sample subsets of real microbiome data sets. Finally, we highlight the ability of this new beta diversity metric to retain the feature loadings linked to sample ordinations revealing salient intercommunity niche feature importance. IMPORTANCE By accounting for the sparse compositional nature of microbiome data sets, robust Aitchison PCA can yield high discriminatory power and salient feature ranking between microbial niches. The software to perform this analysis is available under an open-source license and can be obtained at https://github.com/biocore/DEICODE ; additionally, a QIIME 2 plugin is provided to perform this analysis at https://library.qiime2.org/plugins/q2-deicode .

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2023

SIMS CHARACTERIZATION OF NITROGEN DOPING OF LCLS-II-HE PRODUCTION CAVITIES

The thermal diffusion of nitrogen into the surface of niobium has been shown to yield superior low-loss SRF performance. An effective solution was identified and promptly employed in the production of cryomodules for LCLS-II. With added experience and R&D, a modified process was chosen for use in the upgrade for LCLS-II-HE. Largely motivated by this circumstance, supporting research has significantly refined the technique for making calibrated secondary ion mass spectrometry (SIMS) measurements of the N concentration depth profiles produced by production processes. Standardized reference samples were included with four HE production cavities in their N-doping furnace runs. We report the calibrated dynamic SIMS depth profiles of N, C, and O for these samples, together with the cryogenic acceptance test performance of the associated cavities. Interpretation and comparison with similar samples acquired in other furnaces highlights the importance of intentional process quality control of furnace conditions.

Reece, Charles↗

DOE OSTI2023

SIMS CHARACTERIZATION OF NITROGEN DOPING OF LCLS-II-HE PRODUCTION CAVITIES

Reece, Charles↗

DOE OSTI2019

Finding the Remnants of the Milky Way's Last Neutron Star Mergers

The discovery of a binary neutron star merger (NSM) through both its gravitational wave and electromagnetic emission has revealed these events to be key sites of $r$-process nucleosynthesis. Here, we evaluate the prospects of finding the remnants of Galactic NSMs by detecting the gamma-ray decay lines from their radioactive $r$-process ejecta. We find that 126 Sn, which has several lines in the energy range 415-695 keV and resides close to the second $r$-process peak, is the most promising isotope, because of its half-life $t_{1/2}$ = 2:30(14) 10 5 yr being comparable to the ages of recent NSMs. Using a Monte Carlo procedure, we predict that multiple remnants are detectable as individual sources by next-generation $\gamma$-ray telescopes which achieve sub-MeV line sensitivities of ~18 -8 -10 -6 $\gamma$ cm -2 s -1 . However, given the unknown locations of the remnants, the most promising search strategy is a systematic survey of the Galactic plane and bulge extending to high Galactic latitudes. Individual known supernova remnants which may be mis-classi ed NSM remnants could also be targeted, especially those located outside the Galactic plane. Detection of a moderate sample of Galactic NSM remnants would provide important clues to unresolved issues such as the production of actinides in NSMs, properties of merging NS binaries, and even help distinguish them from rare supernovae as current Galactic $r-$process sources. We also investigate the diffuse flux from longer-lived nuclei (e.g. 182 Hf) that could in principle trace the Galactic spatial distribution of NSMs over longer timescales, but find that the detection of the diffuse flux appears challenging even with next-generation telescopes.

79 ASTRONOMY AND ASTROPHYSICS↗

NASA NTRS1973

Fracture trends identified by ERTS-1 imagery in Utah and Nevada

The author has identified the following significant results. In the Utah-Nevada area, linear structural trends recorded on ERTS-1 imagery conform in part to previously recognized structures. In addition, the ERTS-1 imagery reveals cryptic structures not previously identified and not readily apparent in other imagery. These structures are illustrated by prominent east-west trending structures which appear to be concentrated in pre-volcanic rocks. This suggests that the structures are older than many of those with other trends which are equally prominent in volcanic and non-volcanic terrain. Since the older east-west structures may have controlled early Tertiary emplacement of magma or the ascent of mineralizing fluids, their recognition is important in minerial exploration. Soil-gas sampling and analysis for mercury content is being continued over structures, and projected trends of buried structures which appear, from studies of ERTS-1 imagery, to be favorable to mineralization. Comparison of ERTS-1 and Skylab imagery indicated that ERTS-1 imagery records more previously unrecognized linear structures than the Skylab imagery. In differentiating and identifying different rock types, the Skylab imagery appears to be more effective.

Jensen, M. L.↗