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At least 397 records · Page 22

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DOE OSTI2015

Crystal structure of a new polymorphic modification of niahite, NH{sub 4}MnPO{sub 4} · H{sub 2}O

The crystal structure of a new modification of the niahite mineral NH{sub 4}MnPO{sub 4} · H{sub 2}O, obtained in the form of single crystals under hydrothermal conditions in the Mn{sub 2}O{sub 3}-(NH{sub 4}){sub 3}PO{sub 4}-H{sub 2}O system, is determined by X-ray diffraction (Xcalibur-S-CCD diffractometer, R = 0.0259): a = 17.582, b = 4.909, and c = 5.731 Å; space group D{sub 2h}{sup 16} = Pnam, Z = 4, D{sub x} = 2.497 g/cm{sup 3}. It is shown that the new compound is a polymorphic modification of niahite; it has a layered structure, which differs from the structure of the mineral by the presence of the center of inversion and the doubled a unit cell parameter. It is proposed to consider the minerals and synthetic analogues of the niahite and triphylite groups as members of the common polysomatic series.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2018

Surface Modification of Melamine-Formaldehyde (MF-R) Macroparticles in Complex Plasma

The surface modification of melamine-formaldehyde (MF-R) macroparticles (4.12 ± 0.09 μm in diameter) in dc glow discharges in neon, argon, and an argon–oxygen mixture (90% Ar, 10% O{sub 2}) was studied experimentally. The macroparticles were treated in the discharge plasma for 10, 20, 40, and 60 min. The macroparticles were placed in ordered plasma–dust structures and then extracted from them. The results of atomic force microscopy of the surface profile are presented. Quantitative data on destruction of the surface layer and aspects of its modification are discussed. The amount of substance removed from the particle surface for the exposure time was calculated using the fractal analysis method.

36 MATERIALS SCIENCE↗

DOE OSTI2019

Effect of Plasma-Chemical Surface Modification on the Electron Transport and Work Function in Silicon Crystals

The regularities governing the surface modification of silicon crystals during microwave-plasma microprocessing in different chemically active gaseous media are investigated. This modification is shown to be caused by the formation of built-in surface potentials, which, depending on the semiconductor electrical-conductivity type, differently affect the field-emission properties and surface electron transport in devices based on them.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2018

Prompt and non-prompt J/ψ production and nuclear modification at mid-rapidity in p–Pb collisions at $\mathbf{\sqrt{{ s}_{\text {NN}}}= 5.02}$ TeV

A measurement of beauty hadron production at mid-rapidity in proton-lead collisions at a nucleon–nucleon centre-of-mass energy $\mathbf{\sqrt{{ s}_{\text {NN}}}= 5.02}$ TeV is presented. The semi-inclusive decay channel of beauty hadrons into J / ψ is considered, where the J / ψ mesons are reconstructed in the dielectron decay channel at mid-rapidity down to transverse momenta of 1.3 GeV/c. The b b ¯ production cross section at mid-rapidity, d σbb ¯/ d y, and the total cross section extrapolated over full phase space, σbb ¯, are obtained. This measurement is combined with results on inclusive J / ψ production to determine the prompt J / ψ cross sections. The results in p–Pb collisions are then scaled to expectations from pp collisions at the same centre-of-mass energy to derive the nuclear modification factor RpPb, and compared to models to study possible nuclear modifications of the production induced by cold nuclear matter effects. RpPbis found to be smaller than unity at low pTfor both J / ψ coming from beauty hadron decays and prompt J / ψ.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2023

Measurement of the nuclear modification factor of $b$-jets in 5.02 TeV Pb+Pb collisions with the ATLAS detector

This paper presents a measurement of b-jet production in Pb+Pb and pp collisions at $\sqrt{sNN}$ = 5.02 TeV with the ATLAS detector at the LHC. The measurement uses 260 pb –1 of pp collisions collected in 2017 and 1.4 nb –1 of Pb+Pb collisions collected in 2018. In both collision systems, jets are reconstructed via the anti-$k_t$ algorithm. The b-jets are identified from a sample of jets containing muons from the semileptonic decay of b-quarks using template fits of the muon momentum relative to the jet axis. In pp collisions, b-jets are reconstructed for radius parameters R = 0.2 and R = 0.4, and only R = 0.2 jets are used in Pb+Pb collisions. For comparison, inclusive R = 0.2 jets are also measured using 1.7 nb –1 of Pb+Pb collisions collected in 2018 and the same pp collision data as the b-jet measurement. The nuclear modification factor, $R_{AA}$, is calculated for both b-jets and inclusive jets with R = 0.2 over the transverse momentum range of 80–290 GeV. The nuclear modification factor for b-jets decreases from peripheral to central collisions. The ratio of the b-jet $R_{AA}$ to inclusive jet $R_{AA}$ is also presented and suggests that the $R_{AA}$ for b-jets is larger than that for inclusive jets in central Pb+Pb collisions. The measurements are compared with theoretical calculations and suggest a role for mass and colour-charge effects in partonic energy loss in heavy-ion collisions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2022

Pressure Modification or Barrier Issues during Polymer Flooding Enhanced Oil Recovery

Effective oil displacement from a reservoir requires adequate and properly directed pressure gradients in areas of high oil saturation. If the polymer bank is too large or too viscous during a polymer flood, the pressure drops from the injection well to the polymer front may act as a pressure modification or barrier by usurping most of the downstream driving force for oil displacement. Polymer injection pressures must be limited. The maximum allowable injection pressure is commonly constrained by caprock integrity, injection equipment, and/or regulations, even though fractures can be beneficial to polymer injectivity. This paper examines when the pressure-barrier concept limits the size and viscosity of the polymer bank during a polymer flood. Analytical and numerical methods are used to address this issue. We examine the relevance of the pressure modification concept for a wide variety of circumstances, including oil viscosities ranging from 10 cp to 1650 cp, vertical wells versus horizontal wells, single versus multiple layered reservoirs, permeability contrast, and crossflow between layers. We also examine the relation between the pressure-barrier concept and fractures and fracture extension during polymer injection. We demonstrate that in reservoirs with single layers, the pressure-barrier concept only limits the optimum viscosity of the injected polymer if the mobility of the polymer bank is less than the mobility of the displaced oil bank. The same is true for multizoned reservoirs with no crossflow between layers. Thus, for these cases, the optimum polymer viscosity is likely to be dictated by the mobility of the oil bank, unless other factors intervene. For multizoned reservoirs with free crossflow between layers, the situation is different. A compromise must be reached between injected polymer viscosity and the efficiency of oil recovery. This work is particularly relevant to viscous oil reservoirs where polymer viscosities are substantially lower than the oil viscosity.

58 GEOSCIENCES↗

DOE OSTI2025

Adaptive modification of antiviral defense systems in microbial community under Cr-induced stress

Background The prokaryotic antiviral defense systems are crucial for mediating prokaryote-virus interactions that influence microbiome functioning and evolutionary dynamics. Despite the prevalence and significance of prokaryotic antiviral defense systems, their responses to abiotic stress and ecological consequences remain poorly understood in soil ecosystems. We established microcosm systems with varying concentrations of hexavalent chromium (Cr(VI)) to investigate the adaptive modifications of prokaryotic antiviral defense systems under abiotic stress. Results Utilizing hybrid metagenomic assembly with long-read and short-read sequencing, we discovered that anti- viral defense systems were more diverse and prevalent in heavily polluted soils, which was corroborated by meta-analyses of public datasets from various heavy metal-contaminated sites. As the Cr(VI) concentration increased, prokaryotes with defense systems favoring prokaryote-virus mutualism gradually supplanted those with defense systems incurring high adaptive costs. Additionally, as Cr(VI) concentrations increased, enriched antiviral defense systems exhibited synchronization with microbial heavy metal resistance genes. Furthermore, the proportion of antiviral defense systems carried by mobile genetic elements (MGEs), including plasmids and viruses, increased by approximately 43% and 39%, respectively, with rising Cr concentrations. This trend is conducive to strengthening the dissemination and sharing of defense resources within microbial communities. Conclusions Overall, our study reveals the adaptive modification of prokaryotic antiviral defense systems in soil ecosystems under abiotic stress, as well as their positive contributions to establishing prokaryote-virus mutualism and the evolution of microbial heavy metal resistance. These findings advance our understanding of microbial adaptation in stressful environments and may inspire novel approaches for microbiome manipulation and bioremediation.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2020

Data from Improved Annotation of Untargeted Metabolomics Data through Buffer Modifications That Shift Adduct Mass and Intensity

Annotation of untargeted high-resolution full-scan LC-MS metabolomics data remains challenging due to individual metabolites generating multiple LC-MS peaks arising from isotopes, adducts, and fragments. Adduct annotation is a particular challenge, as the same mass difference between peaks can arise from adduct formation, fragmentation, or different biological species. To address this, here we describe a buffer modification workflow (BMW) in which the same sample is run by LC-MS in both liquid chromatography solvent with 14NH3–acetate buffer and in solvent with the buffer modified with 15NH3–formate. Buffer switching results in characteristic mass and signal intensity changes for adduct peaks, facilitating their annotation. This relatively simple and convenient chromatography modification annotated yeast metabolomics data with similar effectiveness to growing the yeast in isotope-labeled media. Application to mouse liver data annotated both known metabolite and known adduct peaks with 95% accuracy. Overall, it identified 26% of ∼27 000 liver LC-MS features as putative metabolites, of which ∼2600 showed HMDB or KEGG database formula match. This workflow is well suited to biological samples that cannot be readily isotope labeled, including plants, mammalian tissues, and tumors.

Conversion↗

DOE OSTI2015

c-Myc alters substrate utilization and O-GlcNAc protein posttranslational modifications without altering cardiac function during early aortic constriction

Pressure overload cardiac hypertrophy alters substrate metabolism. Prior work showed that myocardial inactivation of c-Myc (Myc) attenuated hypertrophy and decreased expression of metabolic genes after aortic constriction. Accordingly, we hypothesize that Myc regulates substrate preferences for the citric acid cycle during pressure overload hypertrophy from transverse aortic constriction (TAC) and that these metabolic changes impact cardiac function and growth. To test this hypothesis, we subjected mice with cardiac specific, inducible Myc inactivation (MycKO-TAC) and non-transgenic littermates (Cont-TAC) to transverse aortic constriction (TAC; n=7/group). A separate group underwent sham surgery (Sham, n=5). After two weeks, function was measured in isolated working hearts along with substrate fractional contributions to the citric acid cycle by using perfusate with 13C labeled mixed fatty acids, lactate, ketone bodies and unlabeled glucose and insulin. Cardiac function was similar between groups after TAC although +dP/dT and -dP/dT trended towards improvement in MycKO-TAC versus Cont-TAC. Compared to Sham, Cont-TAC had increased free fatty acid fractional contribution with a concurrent decrease in unlabeled (predominately glucose) contribution. The changes in free fatty acid and unlabeled fractional contributions were abrogated by Myc inactivation during TAC (MycKO-TAC). Additionally, protein posttranslational modification by O-GlcNAc was significantly greater in Cont-TAC versus both Sham and MycKO-TAC. Lastly, Myc alters substrate preferences for the citric acid cycle during early pressure overload hypertrophy without negatively affecting cardiac function. Myc also affects protein posttranslational modifications by O-GlcNAc during hypertrophy.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2015

Los Alamos National Laboratory Permit Modification Request for Technical Area 63 Transuranic Waste Facility Hazardous Waste Container Storage Unit (Rev. 3)

This Class 3 permit modification requests the addition of a hazardous waste management unit, the Transuranic Waste Facility (TWF), to the Los Alamos National Laboratory Hazardous Waste Facility Permit (November 2010), (hereinafter referred to as “the Permit”). The Permit was issued by the New Mexico Environment Department (NMED) in November, 1989 and renewed in 2010 (NMED 2010). The Los Alamos National Laboratory (LANL) Environmental Protection Agency (EPA) Identification Number is NM0890010515. The facility is owned by the National Nuclear Security Administration (NNSA) of the Department of Energy (DOE), and is operated jointly by NNSA-DOE and by Los Alamos National Security, LLC (LANS). This permit modification request has been prepared to address requirements in the New Mexico Administrative Code, Title 20, Chapter 4, Part 1 (20.4.1 NMAC), as revised October 2009, that are specific for the proposed new hazardous waste storage operations at the TWF. The renewed Permit contains many of the conditions addressing the requirements of the New Mexico Hazardous Waste Act (NMHWA) and implementing regulations, specifically 40 CFR, that are common to all LANL hazardous waste management units. The relevant sections of the Permit are referenced throughout this document. Together, information provided in this document and in the Permit will meet the applicable requirements specified in 40 CFR Parts 264 and 270 for the proposed unit.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2015

Notification of Class 1 Permit Modification to Attachment B, Part A Application for the Los Alamos National Laboratory Hazardous Waste Facility Permit, EPA ID # NM0890010515

This document contains a notification for a Class 1 Permit Modification to modify the Los Alamos National Laboratory (LANL) Hazardous Waste Facility Permit (Permit) issued to the Department of Energy and the Los Alamos National Security, LLC, collectively known as the Permittees, in November 2010. All changes have been made to Attachment B, Part A Application, and a full, updated form, Revision 10.0, is enclosed. The modification updates the facility contact and address information, and the process codes and design capacity section for Technical Area (TA) 14; TA-16; TA-39; TA-54 West; TA-54, Area G; and TA-55 within the Attachment B, Part A Application. The process codes and design capacity section for TA-14, TA-16, and TA-39 was updated to incorporate a statement that the Permittees have notified of the intent to close units at these locations. The process design capacity for TA-54, Area G has been updated from 3,664,150 gallons to 4,346,590 gallons to account for the TA-54, Area G Pad 11 container storage unit that was added when the Permit was issued in 2010 but at the time did not previously store hazardous waste. The number of units at TA-54, Area G was also updated to 9 units to include this new unit. The process design capacity for TA-55 has also been updated from 178,500 gallons to 207,600 gallons to incorporate the addition of the TA-55-185 container storage unit that was also added when the Permit was issued. The number of storage units at TA-55 was updated to 7 to include the unit. The process design capacity at TA-54 West was changed to 11,660 gallons to correct a typographical error in previous versions of the form.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2017

Covalent Surface Modifications of Carbon Nanotubes.

A report meant to document the chemistries investigated by the author for covalent surface modification of CNTs. Oxidation, cycloaddition, and radical reactions were explored to determine their success at covalently altering the CNT surface. Characterization through infrared spectroscopy, Raman spectroscopy, and thermo gravimetric analysis was performed in order to determine the success of the chemistries employed. This report is not exhaustive and was performed for CNT surface modification exploration as it pertains to the "Next Gen" project.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2017

Engineered Zircaloy Cladding Modifications for Improved Accident Tolerance of LWR Nuclear Fuel

The DOE NEUP sponsored IRP on accident tolerant fuel (ATF) entitled Engineered Zircaloy Cladding Modifications for Improved Accident Tolerance of LWR Nuclear Fuel involved three academic institutions, Idaho National Laboratory (INL), and ATI Materials (ATI). Detailed descriptions of the work at the University of Illinois (UIUC, prime), the University of Florida (UF), the University of Michigan (UMich), and INL are included in this document as separate sections. This summary provides a synopsis of the work performed across the IRP team. Two ATF solution pathways were initially proposed, coatings on monolithic Zr-based LWR cladding material and selfhealing modifications of Zr-based alloys. The coating pathway was extensively investigated, both experimentally and in computations. Experimental activities related to ATF coatings were centered at UIUC, UF, and UMich and involved coating development and testing, and ion irradiation. Neutronic and thermal hydraulic aspects of ATF coatings were the focus of computational work at UIUC and UMich, while materials science aspects were the focus of computational work at UF and INL. ATI provided monolithic Zircaloy 2 and 4 material and a binary Zr-Y alloy material. The selfhealing pathway was investigated with advanced computations only. Beryllium was identified as a valid self-healing additive early in this work. However, all attempts to fabricate a Zr-Be alloy failed. Several avenues of fabrication were explored. ATI ultimately declined our fabrication request over health concerns associated with Be (we note that Be was not part of the original work scope and the ATI SOW). Likewise, Ames Laboratory declined our fabrication request, citing known litigation dating to the 1980s and 1990s involving the U.S. Federal government and U.S. National Laboratory employees involving the use of Be. Materion (formerly, Brush Wellman) also declined our fabrication request, citing the difficulty in working with a highly reactive Zr and Be. International fabrication options were explored in Europe and Asia, but this proved to be impractical, if not impossible. Consequently, experimental investigation of the Zr-Be binary system was dropped and exploration binary Zr-Y binary system was initiated. The motivation behind the Zr-Y system is the known thermodynamic stability of yttria over zirconia.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2019

Exascale Computing Facility Modification (ECFM) Project Requirements Document

The objective of the project is to modify and upgrade the civil, structural, architectural, mechanical, and electrical systems of B453 and an adjacent approximately 3.5 acres of previously developed site. These modifications and upgrades would allow for continued use of B453 to support the increasing demands of the next generation high-performance computers. These modifications and upgrades would also provide enhanced power and cooling for the current and future ATS computers.

42 ENGINEERING↗

DOE OSTI2019

Cas9 Protein Post-translational Modifications (PTMs): A Potential Biomarker of Gene-editing

The clustered regularly interspaced short palindromic repeats (CRISPR) arrays and the CRISPR associated (Cas) proteins comprise a prevalent prokaryotic and archaeal adaptive immune system. The CRISPR/Cas9 system has been coopted for and become the ubiquitous gene-editing system due to the simplicity of requiring minimally the CRISPR RNA components and Cas9 protein for specific DNA sequence alteration. CRISPR/Cas9 has been extensively used for gene-editing a wide range of species with human patient trails currently underway. However, unsanctioned genome editing is a national security and public health threat that can cause serious permanent illness and death as well as having the potential for very long-lasting effects over generations due to genetic inheritance of the gene-edit. While the Cas9 protein would appear as a highly specific indicator of exposure to gene-editing reagents, the bacterial origins of CRISPR/Cas9 creates a daunting problem for detection. Bacterial Cas9 would then generate false-positives for detecting gene-editing by conventional molecular biology techniques. Antibody-based assays for Cas9 would be unable to distinguish between Cas9 expressed in human cells for gene-editing and highly common unrelated Cas9 from bacterial infections. Posttranslational modifications of proteins are highly cell specific and hold the potential for discerning the cellular origins of a Cas9 protein and the differentiating between bacterial and gene-editing CRISPR/Cas9. The work described herein is in progress towards the identification of Cas9 post-translational modifications from bacterial and human cell expressed Cas9.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2023

CHIPFoam Modification to Allow for Modelling SWIFT Foams

SWIFT (Silicon-water in Familiar Template) foams are silicone foams that have a continuous porosity without having any obvious spherical or ellipsoidal pore shapes. Like other foamed rubber, SWIFT foams can experience large reversible deformations. Because of their microstructure, SWIFT foams have a stiffering behavior in compression that is very abrupt compared to most other foamed rubbers. Work by Benedikt reported by Miller showed that fitting compressive test data with the CHIPFoam model in its current form is impractical and inaccurate. This report describes an extension made to CHIPFoam to allow the modeling of SWIFT foams. While the extension allows the modeling of SWIFT foams, it also extends the range of porosity of foams that can be modelled with CHIPFoam to include very high porosity (>99%) foamed rubber. The previous model was unstable for porosities greater than 70%. The changes made to CHIPFoam include the introduction of a critical porosity at which the compressible Danielsson strain energy function that couples volumetric and deviatoric mechanical behavior begins to increase with compression. This new feature also required the introduction of a third term in the multiplicative decomposition of the relative volume, J . The organization of this report is described here. The first section, SWIFT Foam Structure and Mechanical Behavior, describes the structure of SWIFT foams as contrasted to other foamed rubbers. It also contrasts the mechanical behavior of SWIFT foams to other more traditional foamed rubbers. The second section, CHIPFoam Modifications, describes the specific modifications done to be able to modify the delayed rapid compressive stiffening seen in SWIFT foams. The third section, Results, demonstrates the use of the modified model to fit compressive loading response data from a SWIFT foam sample. The fourth section, Conclusions and Further Work, puts the work in perspective and presents likely further work.

36 MATERIALS SCIENCE↗

DOE OSTI2021

Jet charge modification in dense QCD matter

In these proceedings we report a recent calculation of the jet charge modification in heavy-ion relative to proton collisions at the LHC. Jets have played an essential role in constraining theories of in-medium parton shower evolution and in determining the properties of the quark-gluon plasma created in ultra-relativistic nuclear reactions. It is important to extend these studies to flavor-tagged jets and explore observables that are sensitive to their partonic origin. The average jet charge, introduced early on in the history of quantum chromodynamics, is a proxy for the electric charge of the quark or gluon that initiates the jet. In the framework of soft-collinear effective theory, we show how to evaluate the jet charge in a dense strongly-interacting matter environments. We identify observables that can isolate the contribution of in-medium branching from isospin effects and present predictions for the transverse momentum dependence of the jet charge distribution in nucleus-nucleus collisions and its modification relative to the proton case.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2015

The Measurement of Reversible Redox Dependent Post-translational Modifications and Their Regulation of Mitochondrial and Skeletal Muscle Function

Mitochondrial oxidative stress is a common feature of skeletal myopathies across multiple conditions; however, the mechanism by which it contributes to skeletal muscle dysfunction remains controversial. Oxidative damage to proteins, lipids, and DNA has received the most attention, yet an important role for reversible redox post-translational modifications (PTMs) in pathophysiology is emerging. The possibility that these PTMs can exert dynamic control of muscle function implicates them as a mechanism contributing to skeletal muscle dysfunction in chronic disease. Herein, we discuss the significance of thiol-based redox dependent modifications to mitochondrial, myofibrillar and excitation-contraction (EC) coupling proteins with an emphasis on how these changes could alter skeletal muscle performance under chronically stressed conditions. A major barrier to a better mechanistic understanding of the role of reversible redox PTMs in muscle function is the technical challenges associated with accurately measuring the changes of site-specific redox PTMs. Here we will critically review current approaches with an emphasis on sample preparation artifacts, quantitation, and specificity. Despite these challenges, the ability to accurately quantify reversible redox PTMs is critical to understanding the mechanisms by which mitochondrial oxidative stress contributes to skeletal muscle dysfunction in chronic diseases.

Environmental Molecular Sciences Laboratory↗