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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 OSTI2018

Optimizing de novo genome assembly from PCR-amplified metagenomes

Background: Metagenomics has transformed our understanding of microbial diversity across ecosystems, with recent advances enabling de novo assembly of genomes from metagenomes. These metagenome-assembled genomes are critical to provide ecological, evolutionary, and metabolic context for all the microbes and viruses yet to be cultivated. Metagenomes can now be generated from nanogram to subnanogram amounts of DNA. However, these libraries require several rounds of PCR amplification before sequencing, and recent data suggest these typically yield smaller and more fragmented assemblies than regular metagenomes. Methods: Here we evaluate de novo assembly methods of 169 PCR-amplified metagenomes, including 25 for which an unamplified counterpart is available, to optimize specific assembly approaches for PCR-amplified libraries. We first evaluated coverage bias by mapping reads from PCR-amplified metagenomes onto reference contigs obtained from unamplified metagenomes of the same samples. Then, we compared different assembly pipelines in terms of assembly size (number of bp in contigs ≥ 10kb) and error rates to evaluate which are the best suited for PCR-amplified metagenomes. Results: . Read mapping analyses revealed that the depth of coverage within individual genomes is significantly more uneven in PCR-amplified datasets versus unamplified metagenomes, with regions of high depth of coverage enriched in short inserts. This enrichment scales with the number of PCR cycles performed, and is presumably due to preferential amplification of short inserts. Standard assembly pipelines are confounded by this type of coverage unevenness, so we evaluated other assembly options to mitigate these issues. We found that a pipeline combining read deduplication and an assembly algorithm originally designed to recover genomes from libraries generated after whole genome amplification (single-cell SPAdes) frequently improved assembly of contigs ≥ 10kb by 10 to 100-fold for low input metagenomes. Conclusions: PCR-amplified metagenomes have enabled scientists to explore communities traditionally challenging to describe, including some with extremely low biomass or from which DNA is particularly difficult to extract. Here we show that a modified assembly pipeline can lead to an improved de novo genome assembly from PCR-amplified datasets, and enables a better genome recovery from low input metagenomes.

Roux, Simon↗
DOE OSTI2019

Optimizing de novo genome assembly from PCR-amplified metagenomes

Background. Metagenomics has transformed our understanding of microbial diversity across ecosystems, with recent advances enabling de novo assembly of genomes from metagenomes. These metagenome-assembled genomes are critical to provide ecological, evolutionary, and metabolic context for all the microbes and viruses yet to be cultivated. Metagenomes can now be generated from nanogram to subnanogram amounts of DNA. However, these libraries require several rounds of PCR amplification before sequencing, and recent data suggest these typically yield smaller and more fragmented assemblies than regular metagenomes. Methods. Here we evaluate de novo assembly methods of 169 PCR-amplified metagenomes, including 25 for which an unamplified counterpart is available, to optimize specific assembly approaches for PCR-amplified libraries. We first evaluated coverage bias by mapping reads from PCR-amplified metagenomes onto reference contigs obtained from unamplified metagenomes of the same samples. Then, we compared different assembly pipelines in terms of assembly size (number of bp in contigs ≥ 10 kb) and error rates to evaluate which are the best suited for PCR-amplified metagenomes. Results. Read mapping analyses revealed that the depth of coverage within individual genomes is significantly more uneven in PCR-amplified datasets versus unamplified metagenomes, with regions of high depth of coverage enriched in short inserts. This enrichment scales with the number of PCR cycles performed, and is presumably due to preferential amplification of short inserts. Standard assembly pipelines are confounded by this type of coverage unevenness, so we evaluated other assembly options to mitigate these issues. We found that a pipeline combining read deduplication and an assembly algorithm originally designed to recover genomes from libraries generated after whole genome amplification (single-cell SPAdes) frequently improved assembly of contigs ≥10 kb by 10 to 100-fold for low input metagenomes. Conclusions. PCR-amplified metagenomes have enabled scientists to explore communities traditionally challenging to describe, including some with extremely low biomass or from which DNA is particularly difficult to extract. Here we show that a modified assembly pipeline can lead to an improved de novo genome assembly from PCR-amplified datasets, and enables a better genome recovery from low input metagenomes.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2013

Development and Testing of Techniques for In-Ground Stabilization, Size Reduction and Safe Removal of Radioactive Wastes Stored in Large Containments in Burial Grounds - 13591

Radioactive waste materials, including Transuranic (TRU) wastes from laboratories have been stored below ground in large containments at a number of sites in the US DOE Complex, and at nuclear sites in Europe. These containments are generally referred to as caissons or shafts. The containments are in a range of sizes and depths below grade. The caissons at the DOE's Hanford site are cylindrical, of the order of 2,500 mm in diameter, 3,050 mm in height and are buried about 6,000 mm below grade. One type of caisson is made out of corrugated pipe, whereas others are made of concrete with standard re-bar. However, the larger shafts in the UK are of the order of 4,600 mm in diameter, 53,500 mm deep, and 12,000 below grade. This paper describes the R and D work and testing activities performed to date to evaluate the concept of in-ground size reduction and stabilization of the contents of large containments similar to those at Hanford. In practice, the height of the Test Facility provided for a test cell that was approximately 22' deep. That prevented a 'full scale mockup' test in the sense that the Hanford Caisson configuration would be an identical replication. Therefore, the project was conducted in two phases. The first phase tested a simulated Caisson with surrogate contents, and part of a Chute section, and the second phase tested a full chute section. These tests were performed at VJ Technologies Test Facility located in East Haven, CT, as part of the Proof of Design Concept program for studying the feasibility of an in-situ grout/grind/mix/stabilize technology for the remediation of four caissons at the 618-11 Burial Ground at US Department of Energy Hanford Site. The test site was constructed such that multiple testing areas were provided for the evaluation of various tools, equipment and procedures under conditions that simulated the Hanford site, with representative soils and layout dimensions. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Latent Effects of Radiation on Li-ion Batteries in Robots

The rapid development of Li-ion batteries (LIBs) is due to their high energy-density storage capability, which makes them suitable for application in both vehicles (e.g., electrified car) and electronic devices (e.g., cell phone, laptop, etc.), which are currently ubiquitous. Another less common but important application of LIBs is the powering of equipment in extreme environments such as robots operating in a nuclear rescue mission, unmanned vehicles surveying environments exposed to radiation, or vehicles and probes for outer space exploration. In our previous study, coin cells with lithium metal serving as the reference and counter electrode were assembled with either an irradiated cathode or irradiated electrolyte. We have observed an increase in premature battery failure and degradation of capacity of the battery made from irradiated cathodes and battery made from the irradiated electrolyte. For the group with cathodes irradiated to a 9.8 Mrad cumulative dose, the resistance was 2-3 times higher than the control group. On the other hand, cells with irradiated electrolyte showed increased resistance even at very low dose levels. Most importantly, a significant color change to the irradiated electrolyte after a long-term storage in a glove box has been observed. However, the electrolyte did not show any noticeable change immediately after irradiation. We name this phenomenon latent effects, which is more significant than the damage received by batteries due to initial dose. Also, electrolyte irradiated to a medium dose (1.6 Mrad) showed a poorer performance (higher failure rate, higher resistance) than those cells which received high dose (5 Mrad). We attribute this to the latent effect because this group battery was unintentionally assembled 3 days after initial electrolyte irradiation. The existence of latent effects implies that in space missions or post-accident events, instruments equipped with LIBs may fail unpredictably at post-irradiation stages, even if they survive the initial dose or the performance tests conducted after the initial dose. These instruments may fail several days or even weeks after irradiation, depending on the initial cumulative dose and dosage rate. For comprehending the influence of latent effects on the entire battery instead of on the individual components, we performed an in-situ cycling of coin cells made in-house, where the batteries were cycled under irradiation and then cycled again to evaluate their overall capacity fade, cyclability, and cell resistance. Additionally we investigated the effects of battery fading due to radiation on the performance of a drone.

25 ENERGY STORAGE↗
DOE OSTI2015

Low dose evaluation of the antiandrogen flutamide following a Mode of Action approach

ABSTRACT: The dose–response characterization of endocrine mediated toxicity is an on-going debate which is controversial when exploring the nature of the dose–response curve and the effect at the low-end of the curve. To contribute to this debate we have assessed the effects of a wide range of dose levels of the antiandrogen flutamide (FLU) on 7-week male Wistar rats. FLU was administered by oral gavage at doses of 0, 0.001, 0.01, 0.1, 1 and 10 mg/kg/day for 28 days. To evaluate the reproducibility, the study was performed 3 times. The molecular initiating event (MIE; AR antagonism), the key events (LH increase, Leydig cell proliferation and hyperplasia increases) and associated events involved in the mode of action (MOA) of FLU induced testicular toxicity were characterized to address the dose response concordance. Results showed no effects at low doses (< 0.1 mg/kg/day) for the different key events studied. The histopathological changes (Leydig cell hyperplasia) observed at 1 and 10 mg/kg/day were associated with an increase in steroidogenesis gene expression in the testis from 1 mg/kg/day, as well as an increase in testosterone blood level at 10 mg/kg/day. Each key event dose–response was in good concordance with the MOA of FLU on the testis. From the available results, only monotonic dose–response curves were observed for the MIE, the key events, associated events and in effects observed in other sex related tissues. All the results, so far, show that the reference endocrine disruptor FLU induces threshold effects in a standard 28-day toxicity study on adult male rats. - Highlights: • Dose–response characterization of endocrine mediated toxicity is an on-going debate. • A wide range of dose levels of flutamide was evaluated on young adult male rats. • Flutamide induces threshold effects using on standard and molecular tools.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Roll to Roll (R2R) Manufacturing of Electrolysis Electrodes for Low Cost Hydrogen Production: Cooperative Research and Development Final Report, CRADA Number CRD-18-00780

NREL, Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL), which are also referred to collectively herein as the "Contractors" will perform electrode ink development and characterization, focusing on 1) inks with appropriate properties for R2R (gravure and slot-die) coating onto PFSA membrane and 2) catalysts suitable for electrolysis. Participant will develop acceptance criteria and characterization methods for direct coating on the membrane. The purpose of this project is to show feasibility for cost reduction of the electrode through increased throughput and improved material utilization. Successful completion of this project will result in more affordable hydrogen production via proton exchange membrane (PEM) electrolysis by substantially reducing the anode precious metal content and catalyst-coated membrane processing costs. Assists laboratory in achieving programmatic scope, adds new capability to the laboratory's core competencies. This project uses and enhances the laboratory's core competencies, and enhances U.S. competitiveness by utilizing DOE developed intellectual property and/or capabilities. This project will benefit the Fuel Cell subprogram within the EERE Fuel Cell Technologies Office (FCTO) by actively developing materials, formulations, components, and processes for PEM electrolyzer stacks for overcoming critical technical barriers to widespread hydrogen production for zero-emission transportation applications. Through this JWS, NREL, ANL and ORNL are assisting a key domestic industry partner, Proton Energy Systems, Inc., in the area of low-cost electrolyzer electrode formulation and coating technology. After completion of this project, NREL, ANL and ORNL will be able to verify whether the direct deposit coating processes investigated are suitable for producing CCMs for PEM electrolyzers, which is of great interest and benefit to the DOE EERE Fuel Cell Technologies Office (FCTO) and H2@Scale missions.

08 HYDROGEN↗
DOE OSTI2025

Datasets for Custom-trained Machine-learning Interatomic Potentials: Nitric Acid Aqueous Solution

This dataset was generated using an iterative active learning strategy with the ArcaNN software package (https://github.com/arcann-chem/arcann_training) to train machine-learning interatomic potentials (MLIPs) for aqueous nitric acid. Each active-learning cycle consisted of three stages: (1) training, (2) exploration, and (3) labeling. The initial training set comprised approximately 800 randomly selected configurations from a previous study by Lewis et al. (https://doi.org/10.1021/jp205510q), which investigated nitric acid solutions at 2, 3, 4, and 5 mol/L. For all configurations, single-point calculations of atomic forces and total energies were performed at the quantum density functional theory BLYP-D2 and PBE-D3 levels of theory using the CP2K Quickstep module. Valence electrons were treated explicitly, while core electrons on all atoms were represented by norm-conserving Goedecker–Teter–Hutter (GTH) pseudopotentials. Long-range dispersion interactions were accounted for using Grimme dispersion corrections. Wave functions were expanded in a mixed Gaussian-and-plane-wave scheme using TZV2P-MOLOPT basis sets for all elements and an 800 Ry auxiliary plane-wave cutoff for the electron density. Self-consistent field convergence was accelerated using orbital transformation and Direct Inversion in the Iterative Subspace, with a convergence threshold of 10^{-6}. All single-point calculations were carried out in periodic orthorhombic cells whose dimensions match those of the molecular configurations sampled from earlier trajectories. The CELL_REF keyword in CP2K was used to define a fixed reference cell, ensuring consistency in the reference data used for MLIP training, particularly when cell fluctuations are present in NpT simulations. The resulting high-fidelity energies and forces constitute the ground-truth labels used to train the MLIPs contained in this dataset.

Dinpajooh, Mohammadhasan [Pacific Northwest Nation↗
DOE OSTI2023

Chemical contributions to silicon anode calendar aging are dominant over mechanical contributions

Silicon (Si) anodes are a promising candidate for increasing the energy density of lithium (Li)-ion batteries for electric vehicles. However, they have recently been identified as having poor calendar life that is insufficient for commercial needs, in addition to the well-known issue of their poor cycle life resulting from large volume expansion. Here, a specially designed protocol with variable rest periods between intermittent cycling is used to evaluate the impact of the mechanical disruption of Si and solid electrolyte interphase (SEI) from cycling on calendar aging measurements. Si was found to undergo more mechanical degradation during calendar aging with intermittent cycling than graphite. However, Si anode capacity fade was still dominated by time, especially for rest periods greater than or equal to 1 month between cycling. Postmortem dQ/dV half-cell analysis indicated this was mainly due to Li inventory loss and an increase in electrode resistance. Isothermal microcalorimetry further demonstrated that Si passivation is more disrupted than graphite passivation with intermittent cycling and suggested that there may be a chemical buildup of a detrimental species in the electrolyte, leading to a large spike in heat after the Si and SEI are disrupted by cycling.

25 ENERGY STORAGE↗
DOE OSTI2010

Functionalized Nanoporous Silica for Removal of Heavy Metals from Biological Systems; Adsorption and Application

Functionalized nanoporous silica, often referred to as self-assembled monolayers on mesoporous supports (SAMMS) have previously demonstrated the ability to serve as very effective heavy metal sorbents in a range of aquatic and environmental systems suggesting they may be advantageously utilized for biomedical applications such as chelation therapy. Herein we evaluate surface chemistries for heavy metal capture from biological fluids, various facets of the materials biocompatibility and the suitability of these materials as potential therapeutics. Of the materials tested, thiol-functionalized SAMMS proved most capable of removing selected heavy metals from biological solutions (i.e. blood, urine, etc.) As a result, thiol SAMMS was further analyzed to assess the material’s performance under a number of different biologically relevant conditions (i.e. variable pH and ionic strength) as well to gauge any potentially negative cellular effects resulting from interaction with the sorbent, such as cellular toxicity or possible chelation of essential minerals. Additionally, cellular uptake studies demonstrated no cell membrane permeation by the silica-based materials generally highlighting their ability to remain cellularly inert and thus non-toxic. As a result, it has been determined that organic ligand-functionalized nanoporous silica materials could be a valuable material for detoxification therapeutics and potentially other biomedical applications as needed.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Real-time ultrasound-tagging to track the 2D motion of the common carotid artery wall in vivo

Purpose: Tracking the motion of biological tissues represents an important issue in the field of medical ultrasound imaging. However, the longitudinal component of the motion (i.e., perpendicular to the beam axis) remains more challenging to extract due to the rather coarse resolution cell of ultrasound scanners along this direction. The aim of this study is to introduce a real-time beamforming strategy dedicated to acquire tagged images featuring a distinct pattern in the objective to ease the tracking. Methods: Under the conditions of the Fraunhofer approximation, a specific apodization function was applied to the received raw channel data, in real-time during image acquisition, in order to introduce a periodic oscillations pattern along the longitudinal direction of the radio frequency signal. Analytic signals were then extracted from the tagged images, and subpixel motion tracking of the intima–media complex was subsequently performed offline, by means of a previously introduced bidimensional analytic phase-based estimator. Results: The authors’ framework was applied in vivo on the common carotid artery from 20 young healthy volunteers and 6 elderly patients with high atherosclerosis risk. Cine-loops of tagged images were acquired during three cardiac cycles. Evaluated against reference trajectories manually generated by three experienced analysts, the mean absolute tracking error was 98 ± 84 μm and 55 ± 44 μm in the longitudinal and axial directions, respectively. These errors corresponded to 28% ± 23% and 13% ± 9% of the longitudinal and axial amplitude of the assessed motion, respectively. Conclusions: The proposed framework enables tagged ultrasound images of in vivo tissues to be acquired in real-time. Such unconventional beamforming strategy contributes to improve tracking accuracy and could potentially benefit to the interpretation and diagnosis of biomedical images.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2025

Building High-Energy Silicon-Containing Batteries Using Off-The-Shelf Materials

The technology of silicon anodes appears to be reaching maturity, with high-energy Si cells already in pilot-scale production. However, the performance of these systems can be difficult to replicate in academic settings, making it challenging to translate research findings into solutions that can be implemented by the battery industry. Part of this difficulty arises from the lack of access to engineered Si particles and anodes, as electrode formulations and the materials themselves have become valuable intellectual property for emerging companies. Here, we summarize the efforts by Argonne’s Cell Analysis, Modeling, and Prototyping (CAMP) Facility in developing Si-based prototypes made entirely from commercially available materials. We describe the many challenges we encountered when testing high-loading electrodes (>5 mAh cm −2 ) and discuss strategies to mitigate them. With the right electrode and electrolyte design, we show that our pouch cells containing ≥ 70 wt% SiO x can achieve 600–1,000 cycles at C/3 and meet projected energy targets of 700 Wh L −1 and 350 Wh kg −1 . These results provide a practical reference for research teams seeking to advance silicon-anode development using accessible materials.

25 ENERGY STORAGE↗
DOE OSTI2012

Development of Scanning Near-Field Ultrasound Holography as an Add-On Module for AFM systems

The project aimed to develop a standalone module for Atomic Force Microscope systems that the biological and environmental research community could use to image and quantify to a greater extent the interactions between nanoparticles and cells. If successful, it would enable the thousands of biological and environmental researchers with access to atomic force microscopes to perform scanning near field ultrasound holography to image nanoparticle interactions with cells. Over the course of this effort, grantees were able to develop a standalone module capable of performing scanning near field ultrasound holography on a variety of commercial systems. The add-on module was tested on systems from 3 of the major Atomic Force Microscope manufacturers (Veeco, JEOL and Park Systems). Furthermore, the investigators believe that the hardware developed will be capable of performing the technique on any AFM with standard signal access modules. The discrete components previously used to perform the SNFUH technique could cost upward of $\$$40,000. Beyond the cost issue, the components are bulky and cumbersome to work with because of the wiring needed between each of the components when implementing the technique. NanoSonix was able to dramatically reduce both the cost and complexity of implementing SNFUH, developing two functional versions of an add-on module (A&B) using National Instruments hardware as put forth in the proposal. More significantly, NanoSonix exceeded the aims of the proposal by developing completely custom electronics that should enable an almost order of magnitude cost reduction while improving the capability versus the discrete componentry. Because potential biological systems are so complex, biological applications of the technique are very diverse and require very distinct domain knowledge. This inhibits the utilization widespread adoption and penetration of new metrology techniques. Northwestern University and NanoSonix has made it both possible and practical for widespread adoption of the technique through the development of a standalone system with order of magnitude cost reduction and significant reduction in complexity. NanoSonix believes that it can produce the add-on modules and make them available to the academic research community at a price point below $\$$10,000, thereby enabling the biological research community to hardness the over 30,000 AFMs in existence around the world today, approximately 18,000 of which reside in the United States at a very modest incremental cost. Finally, we were able to implement a multi-frequency function generator and simultaneous multi-frequency lock-in amplifier with an internal reference frequency (which significantly simplifies the experimental setup) that it believes could lay the foundation for future non-destructive nanoscale 3-D tomography of buried and embedded sub-structures in cells and tissues. To date, we has been unable to find multiple frequency combinations which yield sufficiently strong mixing at the tip-sample interaction, but believes it is conceptually possible and doing so would enable the use of frequency dependent phase shift to better characterize the subsurface structures. Taken together, we believes that this work has materially advanced the prospects of enabling researchers to develop time-resolved cellular uptake of the nanoparticles used for drug delivery, cancer therapies, gene delivery and gene silencing and to assess cellular uptake of nanoparticles for environmental monitoring/remediation/impact.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2024

IsoForma: An R Package for Quantifying and Visualizing Positional Isomers in Top-Down LC-MS/MS Data

Proteoforms, the different forms of a protein with sequence variations including post-translational modifications (PTMs), execute vital functions in biological systems such as cell signaling and epigenetic regulation. Precisely defining the stoichiometry of PTMs has been challenging because, in the widely used bottom-up proteomics methods, the detection occurs at the peptide level and thus the link between peptides and their specific modification site is lost, resulting in proteoform ambiguity. Advances in top-down mass spectrometry (MS) technology have permitted the direct characterization of intact proteoforms and their exact number of modification sites, allowing for the relative quantification of positional isomers (PI). Proteins with positional isomers refers to proteoforms with identical total mass and set of modifications but varying PTM site combinations. The relative abundance of PI can be estimated by matching proteoform-specific fragment ions to top-down tandem MS (MS2) data to localize and quantify modifications. However, current approaches heavily rely on manual annotation. Here, we present IsoForma, an open-source R package for relative quantification of PI within a single tool. We benchmarked IsoForma’s performance against two existing workflows and highlight the similarity of the results and improvements in speed. Overall, IsoForma provides a streamlined process, reduces the time of conducting isoform-based analyses, and offers an essential framework for developing customized proteoform analysis workflows. Finally, the software is open source and available at https://github.com/EMSL-Computing/isoforma-lib.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Current status of post-irradiation examination for the ATF-1 irradiation

A series of irradiations, referred to as the ATF series, is currently underway to evaluate the feasibility of different Accident Tolerant Fuels for commercial light water reactors. For initial screening, concepts consisting of an uranium bearing phase and cladding were irradiated in stainless steel capsules. These tests provide screening data among concepts to ensure viability of a fuel form going forward and can provide some initial data on fuel performance particularly information about fuel-cladding interaction and fuel behavior at operating temperatures and fission densities. Screening concepts are under irradiation or planned for irradiation at the Advanced Test Reactor of Idaho National Laboratory for a number of industrial partners (AREVA, GE, Westinghouse) and national laboratories (Los Alamos National Laboratory, Oak Ridge National Laboratory). Baseline PIE will be performed on all irradiated rodlets and will consist of visual examinations, neutron radiography, gamma spectrometry, dimensional inspections, fission gas analysis, optical microscopy, and chemical analysis. Additional evaluations may also be performed. The first capsules have arrived at the hot cell for initial post-irradiation examination. Results from initial examinations are presented along with example results from equivalent exams on similar fuel. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2016

Listeria monocytogenes in Stone Fruits Linked to a Multistate Outbreak: Enumeration of Cells and Whole-Genome Sequencing

In 2014, the identification of stone fruits contaminated with led to the subsequent identification of a multistate outbreak. Simultaneous detection and enumeration of L. monocytogenes were performed on 105 fruits, each weighing 127 to 145 g, collected from 7 contaminated lots. The results showed that 53.3% of the fruits yielded L. monocytogenes (lower limit of detection, 5 CFU/fruit), and the levels ranged from 5 to 2,850 CFU/fruit, with a geometric mean of 11.3 CFU/fruit (0.1 CFU/g of fruit). Two serotypes, IVb-v1 and 1/2b, were identified by a combination of PCR- and antiserum-based serotyping among isolates from fruits and their packing environment; certain fruits contained a mixture of both serotypes. Single nucleotide polymorphism (SNP)-based whole-genome sequencing (WGS) analysis clustered isolates from two case-patients with the serotype IVb-v1 isolates and distinguished outbreak-associated isolates from pulsed-field gel electrophoresis (PFGE)-matched, but epidemiologically unrelated, clinical isolates. The outbreak-associated isolates differed by up to 42 SNPs. All but one serotype 1/2b isolate formed another WGS cluster and differed by up to 17 SNPs. Fully closed genomes of isolates from the stone fruits were used as references to maximize the resolution and to increase our confidence in prophage analysis. Putative prophages were conserved among isolates of each WGS cluster. All serotype IVb-v1 isolates belonged to singleton sequence type 382 (ST382); all but one serotype 1/2b isolate belonged to clonal complex 5.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2015

Managing work flow and logistic at waste processing facilities using the waste compliance and tracking system - 15392

Work flow and logistics at a busy radioactive waste processing complex or permitted treatment, storage, and disposal facility (TSDF) can pose a monumental challenge. An efficient operation requires good communication between engineering, logistics, and waste operators. The Los Alamos National Laboratory (LANL) has implemented an application that facilitates seamless communication of work flow requirements, between engineering, logistics, and waste operations personnel in the field. The Waste Compliance and Tracking System (WCATS), a comprehensive waste management system designed at LANL, provides four key elements to support logistics: (a) the container work path, (b) directed unit operation requests, (c) notification of pending operations, and (d) real-time status tools for office and field workers. The combination of these elements allows everyone to function as a team, with a shared knowledge of what is needed to accomplish facility objectives. The first element is like a road map indicating which unit operations are needed and in what sequence they should be performed; this is referred to as a 'work path'. It automatically routes a waste item or container from operation to operation. For example, a given work path might indicate that waste items require radiological survey, radioassay, and a technical review, in that order. When the work path is assigned to a container, the system enforces the correct order of operations. Directed unit operation 'requests', the second element, fills a gap between pre-planned, formal 'work path' activities and the need for flexibility to direct preparatory operations or deal with unexpected issues, like staging or mining containers in preparation for a shipment or transferring containers from one storage unit to another to clear a path for building maintenance. Logistics engineers prepare these 'requests', and the system monitors the status and completion of the work. The third element, notifications, allows team members to subscribe to and receive notice that an operation is pending, initiated, or complete. This functionality supports a range of communication options, including e-mail, cell phone, pager, or application in-box messaging. Notifications allow waste operations personnel to multi-task, and remain in the loop on the status of facility-wide activities. Finally, the fourth element provides tools that communicate work path pending operations and directed requests to field workers on their mobile computer, allowing them to mine or pick containers from storage units, and leverage the capabilities of a bar-code scanner to avoid selection mistakes. Oversight and summary tools are provided, allowing logistics personnel to monitor work path and request task status, identify work-flow bottlenecks, and maximize the efficiency of waste operations. The Waste Compliance and Tracking System (WCATS) provides an innovative, comprehensive set of tools that allow large-scale radioactive waste processing facilities to manage logistics, maximize efficient use of the workforce, and create a team environment, where everyone from management to the waste handlers have an understanding of the work load and what needs to be accomplished. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Decoupling electrode kinetics to elucidate reaction mechanisms in alkaline water electrolysis

Alkaline water electrolysis (AWE) presents key advantages, including reduced material costs, enhanced operational stability, and compatibility with non-precious metal catalysts, positioning it as a scalable route for hydrogen production. In this study, we introduce a minimally invasive single-cell configuration incorporating a reference electrode via diaphragm extension to form an internal ion channel. This setup, combined with an interfaced potentiostat and auxiliary electrometer, enables real-time, independent monitoring of anode and cathode behavior, offering high-resolution electrochemical diagnostics. While it is well established that the hydrogen evolution reaction (HER) exhibits sluggish kinetics in alkaline media, our study reveals that this limitation persists even in practical AWE systems where nickel-based substrates are used as electrodes. This observation is supported by both experimental data and voltage breakdown modeling. Arrhenius-type analysis reveals that localized electric fields induced by catalysts shift the reaction kinetics from classical Butler–Volmer behavior toward a Marcus-like regime, where interfacial molecular dynamics and bimolecular charge transfer dominate. We propose a semi-empirical model and a surficial reaction mechanism to describe these dynamics. This work underscores the critical need for cathode innovation and provides a rational framework for designing advanced catalysts and electrode architectures to optimize AWE performance.

08 HYDROGEN↗