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DOE OSTI2014

Note: Design and construction of a multi-scale, high-resolution, tube-generated X-Ray computed-tomography system for three-dimensional (3D) imaging

The design and construction of a high resolution modular x-ray computed tomography (XCT) system is described. The approach for meeting a specified set of performance goals tailored toward experimental versatility is highlighted. The instrument is unique in its detector and x-ray source configuration, both of which enable elevated optimization of spatial and temporal resolution. The process for component selection is provided. The selected components are specified, the custom component design discussed, and the integration of both into a fully functional XCT instrument is outlined. The novelty of this design is a new lab-scale detector and imaging optimization through x-ray source and detector modularity.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2023

Techno-Economic Case Study: Fermentation Cost Impacts from Selected Critical Material Attributes

This report summarizes analysis conducted to support a case study under the Feedstock-Conversion Interface Consortium (FCIC) focused on techno-economic analysis (TEA) modeling to quantify the economic implications of biomass hydrolysate substrate variability on fermentation performance and resultant biorefinery fuel yields. It is known that fermentation inhibitors or byproducts, as may either come from constituents in the biomass feedstock or imparted through biorefinery processing operations, can detrimentally impact fermentation rates and yields. However, it is often difficult to isolate fermentation impacts to individual components given the complex nature of biomass varying simultaneously in multiple attributes from one lot to another. For this study, we worked with FCIC researchers to obtain data on key fermentation performance metrics, namely productivity rates and conversion yields, across a number of material attribute species previously selected by the researchers as "critical" attributes which may be found in hydrolysate used as microbial carbon sources during fermentation. These data were run through TEA models to estimate resultant impacts on biorefinery economics, reported as minimum fuel selling price (MFSP). Overall, the trends in MFSP closely followed fuel yields, in turn tied to fermentation process yields and selectivity, with minimal economic impact from variations in fermentation productivity.

09 BIOMASS FUELS↗

DOE OSTI2020

ABINIT: Overview and focus on selected capabilities

ABINIT is probably the first electronic-structure package to have been released under an open-source license about 20 years ago. It implements density functional theory, density-functional perturbation theory (DFPT), many-body perturbation theory (GW approximation and Bethe–Salpeter equation), and more specific or advanced formalisms, such as dynamical mean-field theory (DMFT) and the “temperature-dependent effective potential” approach for anharmonic effects. Relying on planewaves for the representation of wavefunctions, density, and other space-dependent quantities, with pseudopotentials or projector-augmented waves (PAWs), it is well suited for the study of periodic materials, although nanostructures and molecules can be treated with the supercell technique. The present article starts with a brief description of the project, a summary of the theories upon which ABINIT relies, and a list of the associated capabilities. It then focuses on selected capabilities that might not be present in the majority of electronic structure packages either among planewave codes or, in general, treatment of strongly correlated materials using DMFT; materials under finite electric fields; properties at nuclei (electric field gradient, Mössbauer shifts, and orbital magnetization); positron annihilation; Raman intensities and electro-optic effect; and DFPT calculations of response to strain perturbation (elastic constants and piezoelectricity), spatial dispersion (flexoelectricity), electronic mobility, temperature dependence of the gap, and spin-magnetic-field perturbation. The ABINIT DFPT implementation is very general, including systems with van der Waals interaction or with noncollinear magnetism. Community projects are also described: generation of pseudopotential and PAW datasets, high-throughput calculations (databases of phonon band structure, second-harmonic generation, and GW computations of bandgaps), and the library libpaw. ABINIT has strong links with many other software projects that are briefly mentioned.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2020

Erratum to: Soft- and reactive landing of ions onto surfaces: concepts and applications

Soft- and reactive landing of mass-selected ions is gaining attention as a promising approach for the precisely-controlled preparation of materials on surfaces that are not amenable to deposition using conventional methods. A broad range of ionization sources and mass filters are available that make ion soft-landing a versatile tool for surface modification using beams of hyperthermal (<100?eV) ions. The ability to select the mass-to-charge ratio of the ion, its kinetic energy and charge state, along with precise control of the size, shape, and position of the ion beam on the deposition target distinguishes ion soft landing from other surface modification techniques. Soft- and reactive landing have been used to prepare interfaces for practical applications as well as precisely-defined model surfaces for fundamental investigations in chemistry, physics, and materials science. For instance, soft- and reactive landing have been applied to study the surface chemistry of ions isolated in the gas-phase, prepare arrays of proteins for high-throughput biological screening, produce novel carbon-based and polymer materials, enrich the secondary structure of peptides and the chirality of organic molecules, immobilize electrochemically-active proteins and organometallics on electrodes, create thin films of complex molecules, and immobilize catalytically active organometallics as well as ligated metal clusters. In addition, soft landing has enabled investigation of the size-dependent behavior of bare metal clusters in the critical subnanometer size regime where chemical and physical properties do not scale predictably with size. The morphology, aggregation, and immobilization of larger bare metal nanoparticles, which are directly relevant to the design of catalysts as well as improved memory and electronic devices, have also been studied using ion soft landing. This review article begins in section 1 with a brief introduction to the existing applications of ion soft- and reactive landing. Section 2 provides an overview of the ionization sources and mass filters that have been used to date for soft landing of mass-selected ions. A discussion of the competing processes that occur during ion deposition as well as the types of ions and surfaces that have been investigated follows in section 3. Section 4 discusses the physical phenomena that occur during and after ion soft landing, including retention and reduction of ionic charge along with factors that impact the efficiency of ion deposition. The influence of soft landing on the secondary structure and biological activity of complex ions is addressed in section 5. Lastly, an overview of the structure and mobility as well as the catalytic, optical, magnetic, and redox properties of bare ionic clusters and nanoparticles deposited onto surfaces is presented in section 6. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 35:439–479, 2016.

Johnson, Grant E.↗

DOE OSTI2013

Organic fluids in a supercritical Rankine cycle for low temperature power generation

This paper presents a performance analysis of a supercritical organic Rankine cycle (SORC) with various working fluids with thermal energy provided from a geothermal energy source. In the present study, a number of pure fluids (R23, R32, R125, R143a, R134a, R218, and R170) are analyzed to identify the most suitable fluids for different operating conditions. The source temperature is varied between 125 C and 200 C, to study its effect on the efficiency of the cycle for fixed and variable pressure ratios. The energy and exergy efficiencies for each working fluid are obtained and the optimum fluid is selected. It is found that thermal efficiencies as high as 21% can be obtained with 200 C source temperature and 10 C cooling water temperature considered in this study. For medium source temperatures (125 150 C), thermal efficiencies higher than 12% are obtained.

Vidhi, Rachana↗

DOE OSTI2017

A Very Large (θ{sub E} ≳ 40″) Strong Gravitational Lens Selected with the Sunyaev–Zel’dovich Effect: PLCK G287.0+32.9 (z = 0.38)

Since galaxy clusters sit at the high end of the mass function, the number of galaxy clusters both massive and concentrated enough to yield particularly large Einstein radii poses useful constraints on cosmological and structure formation models. To date, less than a handful of clusters are known to have Einstein radii exceeding ∼40{sup ′′} (for a source at z{sub s}≃2, nominally). Here, we report an addition to that list of the Sunyaev–Zel’dovich (SZ) selected cluster, PLCK G287.0+32.9 (z = 0.38), the second-highest SZ-mass (M {sub 500}) cluster from the Planck catalog. We present the first strong-lensing analysis of the cluster, identifying 20 sets of multiply imaged galaxies and candidates in new Hubble Space Telescope (HST) data, including a long, l∼22{sup ′′} giant arc, as well as a quadruply imaged, apparently bright (magnified to J{sub F110W}=25.3 AB), likely high-redshift dropout galaxy at z{sub phot}=6.90 [6.13–8.43] (95% C.I.). Our analysis reveals a very large critical area (1.55 arcmin{sup 2}, z{sub s}≃2), corresponding to an effective Einstein radius of θ{sub E}∼42{sup ′′}. The model suggests the critical area will expand to 2.58 arcmin{sup 2} (θ{sub E}∼54{sup ′′}) for sources at z{sub s}∼10. Our work adds to recent efforts to model very massive clusters toward the launch of the James Webb Space Telescope, in order to identify the most useful cosmic lenses for studying the early universe. Spectroscopic redshifts for the multiply imaged galaxies and additional HST data will be necessary for refining the lens model and verifying the nature of the z∼7 dropout.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2018

Prevalence of elevated blood lead levels among pregnant women and sources of lead exposure in rural Bangladesh: A case control study

Highlights: • Prenatal blood lead levels and lead sources are assessed in rural Bangladesh. • Elevated blood lead levels are found among pregnant women. • Multiple possible sources of lead are identified; all related to food. • Future lead prevention studies should investigate food storage and production. Prenatal and early childhood lead exposures impair cognitive development. We aimed to evaluate the prevalence of elevated blood lead levels (BLLs) among pregnant women in rural Bangladesh and to identify sources of lead exposure. We analyzed the BLLs of 430 pregnant women randomly selected from rural communities in central Bangladesh. Fifty-seven cases were selected with the highest BLLs, ≥ 7 μg/dL, and 59 controls were selected with the lowest BLLs, < 2 μg/dL. An exposure questionnaire was administered and soil, rice, turmeric, water, traditional medicine, agrochemical, and can samples were analyzed for lead contamination. Of all 430 women, 132 (31%) had BLLs > 5 μg/dL. Most women with elevated BLLs were spatially clustered. Cases were 2.6 times more likely than controls to consume food from a can (95% CI 1.0–6.3, p = 0.04); 3.6 times more likely to use Basudin, a specific brand of pesticide (95% CI 1.6–7.9, p = 0.002); 3.6 times more likely to use Rifit, a specific brand of herbicide (95% CI 1.7–7.9, p = 0.001); 2.9 times more likely to report using any herbicides (95% CI 1.2–7.3, p = 0.02); and 3.3 times more likely to grind rice (95% CI 1.3–8.4, p = 0.01). Five out of 28 food storage cans were lead-soldered. However, there was minimal physical evidence of lead contamination from 382 agrochemical samples and 129 ground and unground rice samples. Among 17 turmeric samples, one contained excessive lead (265 μg/g) and chromium (49 μg/g). Overall, we found evidence of elevated BLLs and multiple possible sources of lead exposure in rural Bangladesh. Further research should explicate and develop interventions to interrupt these pathways.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2014

Pyrolysis Oil-Based Lipid Production as Biodiesel Feedstock by Rhodococcus opacus

Light oil from pyrolysis, which accounts for ~10 % carbon yield of the starting biomass, is a complex aqueous product that is difficult to utilize and usually discarded. This work presents the feasibility of light oil as a sole carbon source to support the growth of Rhodococcus opacus (R. opacus) that in turn accumulate triacylglycerols as biodiesel feedstock. Two types of bacteria (R. opacus PD630 and DSM 1069) were selected in this study. Research results showed that after short adaption periods both strains can grow well on this complex carbon source, as proved by the consumption of oligomers and monomers in light oil. Lipid content by R. opacus PD630 and DSM 1069 was observed up to 25.8 % and 22.0 % of cell dry weight, respectively. Palmitic and stearic acids were found to be the predominant fatty acids in these bacterial cells. In addition, the light oil-based lipid production can be enhanced by reducing the pH value from 7 to 4, especially in case of DSM 1069.

09 BIOMASS FUELS↗

DOE OSTI2022

Managing Sn-Supply to Tune Surface Characteristics of Vapor-Diffusion Coating of Nb₃Sn

Nb₃Sn promises better RF performance (Q and E_{acc}) than niobium at any given temperature because of superior superconducting properties. Nb₃Sn-coated SRF cavities are now produced routinely by growing a few microns thick Nb₃Sn films inside Nb cavities via the tin vapor diffusion technique. Sn evaporation and consumption during the growth process notably affect the quality of the coating. Aiming at favorable surface characteristics that could enhance the RF performance, many coatings were produced by varying Sn sources and temperature profiles. Coupon samples were examined using different material characterization techniques, and a selected few sets of coating parameters were used to coat 1.3 GHz single-cell cavities for RF testing. The Sn supply’s careful tuning is essential to manage the microstructure, roughness, and overall surface characteristics of the coating. We summarize the material analysis of witness samples and discuss the performance of several Nb₃Sn-coated single-cell cavities linked to Sn-source characteristics and observed Sn consumption during the film growth process.

Pudasaini, U.↗

DOE OSTI2021

Managing Sn-supply to tune surface characteristics of vapor-diffusion coating of Nb3Sn

Pudasaini, U.↗

DOE OSTI2015

Isolation and Purification of the Xenon Fraction of 252Cf Spontaneous Fission Products for the Production of Radio Xenon Calibration Standards

The presence of radioactive xenon isotopes indicates that fission events have occurred, and is used to help enforce the Comprehensive Test Ban Treaty. Idaho National Laboratory (INL) produces 135Xe, 133mXe, 133Xe, and 131mXe standards used for the calibration and testing of collection equipment and analytical techniques used to monitor radio xenon emissions. At INL, xenon is produced and collected as one of several spontaneous fission products from a 252Cf source. Further chromatographic purification of the fission gases ensures the separations of the xenon fraction for selective collection. An explanation of the fission gas collection, separation and purification is presented. Additionally, the range of 135Xe to 133Xe ratio that can be isolated is explained. This is an operational update on the work introduced previously, now that it is in operation and has been recharged with a second 252Cf source.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

DOE OSTI2023

Powerful Radio Sources in the Southern Sky. II. A Swift X-Ray Perspective

We recently constructed the G4Jy-3CRE, a catalog of extragalactic radio sources based on the GLEAM 4-Jy (G4Jy) sample, with the aim of increasing the number of powerful radio galaxies and quasars with similar selection criteria to those of the revised release of the Third Cambridge Catalog (3CR). The G4Jy-3CRE consists of a total of 264 radio sources mainly visible from the Southern Hemisphere. Here, we present an initial X-ray analysis of 89 G4Jy-3CRE radio sources with archival X-ray observations from the Neil Gehrels Swift Observatory. We reduced a total of 624 Swift observations, for about 0.9 Ms of integrated exposure time. We found X-ray counterparts for 59 radio sources belonging to the G4Jy-3CRE, nine of them showing extended X-ray emission. The remaining 30 sources do not show any X-ray emission associated with their radio cores. Our analysis demonstrates that X-ray snapshot observations, even if lacking uniform exposure times, as those carried out with Swift, allow us to (i) verify and/or refine the host galaxy identification; (ii) discover the extended X-ray emission around radio galaxies of the intracluster medium when harbored in galaxy clusters, as the case of G4Jy 1518 and G4Jy 1664; and (iii) detect X-ray radiation arising from their radio lobes, as for G4Jy 1863.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2023

Structural basis for enzymatic terminal C–H bond functionalization of alkanes

Alkane monooxygenase (AlkB) is a widely occurring integral membrane metalloenzyme that catalyzes the initial step in the functionalization of recalcitrant alkanes with high terminal selectivity. AlkB enables diverse microorganisms to use alkanes as their sole carbon and energy source. Here we present the 48.6-kDa cryo-electron microscopy structure of a natural fusion from Fontimonas thermophila between AlkB and its electron donor AlkG at 2.76 Å resolution. The AlkB portion contains six transmembrane helices with an alkane entry tunnel within its transmembrane domain. A dodecane substrate is oriented by hydrophobic tunnel-lining residues to present a terminal C–H bond toward a diiron active site. AlkG, an [Fe–4S] rubredoxin, docks via electrostatic interactions and sequentially transfers electrons to the diiron center. The archetypal structural complex presented reveals the basis for terminal C–H selectivity and functionalization within this broadly distributed evolutionary class of enzymes.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2015

Soft- and reactive landing of ions onto surfaces: Concepts and applications: CONCEPTS AND APPLICATIONS

Soft- and reactive landing of mass-selected ions is gaining attention as a promising approach for the precisely-controlled preparation of materials on surfaces that are not amenable to deposition using conventional methods. A broad range of ionization sources and mass-filters are available that make ion soft-landing a versatile tool for surface modification using beams of hyperthermal (< 100 eV) ions. The ability to select the mass-to-charge ratio of the ion, its kinetic energy and charge state, along with precise control of the size, shape, and position of the ion beam on the deposition target distinguishes ion soft landing from other surface modification techniques. Soft- and reactive landing have been used to prepare interfaces for practical applications as well as precisely-defined model surfaces for fundamental investigations in chemistry, physics, and materials science. For instance, soft- and reactive landing have been applied to study the surface chemistry of ions isolated in the gas-phase, prepare arrays of proteins for high-throughput biological screening, produce novel carbon-based and polymer materials, enrich the secondary structure of peptides and the chirality of organic molecules, immobilize electrochemically-active proteins and organometallics on electrodes, create thin films of complex molecules, and immobilize catalytically active organometallics as well as ligated metal clusters. In addition, soft landing has enabled investigation of the size-dependent behavior of bare metal clusters in the critical subnanometer size regime where chemical and physical properties do not scale predictably with size. The morphology, aggregation, and immobilization of larger bare metal nanoparticles, which are directly relevant to the design of catalysts as well as improved memory and electronic devices, have also been studied using ion soft landing. This review article begins in section 1 with a brief introduction to the existing applications of ion soft- and reactive landing. Section 2 provides an overview of the ionization sources and mass filters that have been used to date for soft landing of mass-selected ions. A discussion of the competing processes that occur during ion deposition as well as the types of ions and surfaces that have been investigated follows in section 3. Section 4 discusses the physical phenomena that occur during and after ion soft landing including retention and reduction of ionic charge along with factors that impact the efficiency of ion deposition. The influence of soft landing on the secondary structure and biological activity of complex ions is addressed in section 5. Lastly, an overview of the structure and mobility as well as the catalytic, optical, magnetic, and redox properties of bare ionic clusters and nanoparticles deposited onto surfaces is presented in section 6.

Environmental Molecular Sciences Laboratory↗

DOE OSTI2020

Time Series Classification for Locating Forced Oscillation Sources

Here, this article presents a machine learning based time-series classification method for using synchrophasor measurements to locate the source of forced oscillation (FO) for fast disturbance removal. First, multivariate time series (MTS) matrices are constructed by the most informative measurements selected by sequential feature selection from each power plant. Then, the Mahalanobis matrix is trained such that the Mahalanobis distance between the MTSs from the same class (i.e., with the same FO source location) are minimized and from different classes (i.e., with different FO source locations) are maximized. This allows MTSs to be classified by classifiers with class membership corresponding to the location of each FO source. To meet the runtime requirements of online matching, class templates are constructed to reduce data size and improve matching efficiency. To account for uncertainty in identifying the exact beginning of an FO event, dynamic time warping is used to align the out-of-sync MTSs. IEEE 39bus and WECC 179bus systems are used for algorithm development and validation. Simulation results demonstrate that the algorithm meets online operation runtime requirement with high accuracy using misaligned data sets.

42 ENGINEERING↗

DOE OSTI2026

Brightest Cluster Galaxy ellipticity as proxy for halo shape: Orientation bias, assembly bias, and potential selection effects in SZ-selected clusters

The orientation of triaxial galaxy clusters with respect to the line-of-sight is expected to be one of the prime sources of scatter and potential bias in optical observables (e.g., richness and weak-lensing signal) of galaxy clusters. In this work, we use the observed shape of the central Brightest Cluster Galaxy (BCG) as proxy for the orientation along the line-of-sight for clusters selected via the Sunyaev-Zel'dovich (SZ) effect from the South Pole Telescope (SPT) and Atacama Cosmology Telescope (ACT) surveys, matched to optically selected clusters from the Dark Energy Survey Year 3 (DES). We construct two samples of clusters that are designed to be identical in SZ mass estimate and redshift but with the roundest vs. the most elliptical BCGs, which we expect to correspond to BCGs (and clusters) with major axes aligned along the line-of-sight vs. in the plane of the sky, respectively. We find that the optical richness of round-BCG clusters is $\sim 10$% larger than that of elliptical-BCG clusters, in agreement with the expectation from projection effects and presenting the first such detection in data. The density profiles, however, are not in agreement with the expectation from projection effects: the 1-halo term (below $6~h^{-1}\rm{Mpc}$) of both the weak-lensing and galaxy density profiles are the same for the subsamples, contrary to previous studies based on X-ray selected clusters. In the 2-halo regime (above $6~h^{-1}\rm{Mpc}$), we find a significant excess of the elliptical-BCG cluster profiles compared to the round-BCG cluster profiles, which is the opposite of the expectation from numerical simulations. We hypothesize that the intrinsic shape of the BCG reflects not just the orientation angle, but also intrinsic properties of the cluster which can affect both the SZ signal and the amplitude of the 2-halo term.

Srinivasan, Radhakrishnan [SUNY, Stony Brook] (ORC↗

DOE OSTI2017

Selective C−H Bond Cleavage in Methane by Small Gold Clusters

Abstract Methane represents the major constituent of natural gas. It is primarily used only as a source of energy by means of combustion, but could also serve as an abundant hydrocarbon feedstock for high quality chemicals. One of the major challenges in catalysis research nowadays is therefore the development of materials that selectively cleave one of the four C−H bonds of methane and thus make it amenable for further chemical conversion into valuable compounds. By employing infrared spectroscopy and first‐principles calculations it is uncovered herein that the interaction of methane with small gold cluster cations leads to selective C−H bond dissociation and the formation of hydrido methyl complexes, H‐Au x + ‐CH 3 . The distinctive selectivity offered by these gold clusters originates from a fine interplay between the closed‐shell nature of the d states and relativistic effects in gold. Such fine balance in fundamental interactions could prove to be a tunable feature in the rational design of a catalyst.

Lang, Sandra M.↗

DOE OSTI2017

Models and Simulation Environment for the Design and Optimization of Hybrid Energy Systems

The energy landscape in the U.S. is changing with proposed federal regulations limiting carbon dioxide emissions and with government credits for 'clean' energy technologies. This shift in the market conditions, especially in deregulated markets, has already resulted in the closing of coal power plants. Previously these coal plants served to balance variation in load. The resulting loss of electricity production is being made up in part with increased renewable generation. This set of governmental policy changes potentially presents expanded opportunities for both renewable energy and nuclear energy to become significant energy sources in the future. Potential synergies exist that can reduce greenhouse gas (GHG) emissions and provide affordable, sustainable energy. Combining multiple energy production, conversion, storage, and consumption facilities can leverage these potential synergies. This research focuses on integrating nuclear power plants within systems with increased renewable penetration, referred to as a nuclear renewable hybrid energy system (NRHES). Industrial-scale nuclear renewable hybrid energy systems have the potential to provide grid services such as dispatchable generation, storage, ancillary services, and power regulation. The problem of designing, analyzing, and optimizing the NHRES is being undertaken by a multi-laboratory team. The effort requires the collaboration of experts across engineering disciplines with methods and results to be shared by these experts. To facilitate collaborations a common system modeling and analysis language is adopted along with open-source libraries and interface standards that support data exchange among the models. Modelica was selected as the common language based on its prior use by team members at each of Idaho National Laboratory, Oak Ridge National Laboratory, and Argonne National Laboratory.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗