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All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

A Study of the Residual Gas Composition in the Vacuum System of the Cyclotron of the Ioffe Physical Technical Institute

Mass spectra of residual gas molecules in vacuum system of the cyclotron of the Ioffe Physical Technical Institute (St. Petersburg) were obtained under various experimental conditions using a compact FT-200 time-of-flight mass spectrometer designed and manufactured at the institute. The measurements were performed in the vacuum chamber of cyclotron and in a terminal part of the ion guiding channel near the sample irradiation chamber. It is established that main contributions to residual gas composition in the cyclotron vacuum chamber are related to molecules of the vacuum oil (up to 82 vol %) and water molecules (up to 15–17 vol %), Water molecules also account for the main contribution (up to 63 vol %) to residual gas composition in the terminal part of the ion guiding channel near the sample irradiation chamber with a polymer film. The obtained data provide a basis for upgrade of the cyclotron complex of the Ioffe Physical Technical Institute.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Waste To Wisdom: Utilizing Forest Residues for the Production of Bioenergy and Biobased Products

The Waste to Wisdom project was part of the Biomass Research and Development Initiative (BRDI) and funded by the Department of Energy (DE-EE0006297) at an amount of $5.8 million. Our interdisciplinary research team, consisting of academics, business professionals, and land managers, worked together for about four years (September 2013 to December 2017) to: 1) conduct field-based experiments to develop innovative tools and systems that improve the economics, accessibility, and production of quality feedstocks from forest residues, 2) develop and test stand-alone in-woods or near-the-forest biomass conversion technologies (BCTs) for the production of biochar, torrefied wood, and briquettes, and 3) perform analyses to evaluate the economic feasibility of commercial deployment of BCTs and to quantify the life cycle economic and environmental benefits of utilizing forest residues with BCTs for the production of bioenergy and bioproducts. The research papers presented in this Special Issue cover key aspects of the research efforts and findings made by the project team. We encourage the audience to visit the project web site (http://wastetowisdom.com/) to learn more about the team’s research on feedstock development, biomass conversion technologies, and the financial and environmental benefits of utilizing forest residues for production of bioenergy and biobased products. Keywords: Air quality, Biomass conversion technology, Forest harvesting, Woody biomass.

Agriculture↗
DOE OSTI2014

Dissecting the Functional Role of Key Residues in Triheme Cytochrome PpcA: A Path to Rational Design of G. sulfurreducens Strains with Enhanced Electron Transfer Capabilities

PpcA is the most abundant member of a family of five triheme cytochromes c7 in the bacterium Geobacter sulfurreducens (Gs) and is the most likely carrier of electrons destined for outer surface during respiration on solid metal oxides, a process that requires extracellular electron transfer. This cytochrome has the highest content of lysine residues (24%) among the family, and it was suggested to be involved in e2/H+ energy transduction processes. In the present work, we investigated the functional role of lysine residues strategically located in the vicinity of each heme group. Each lysine was replaced by glutamine or glutamic acid to evaluate the effects of a neutral or negatively charged residue in each position. The results showed that replacing Lys9 (located near heme IV), Lys18 (near heme I) or Lys22 (between hemes I and III) has essentially no effect on the redox properties of the heme groups and are probably involved in redox partner recognition. On the other hand, Lys43 (near heme IV), Lys52 (between hemes III and IV) and Lys60 (near heme III) are crucial in the regulation of the functional mechanism of PpcA, namely in the selection of microstates that allow the protein to establish preferential e2/H+ transfer pathways. The results showed that the preferred e2/H+ transfer pathways are only established when heme III is the last heme to oxidize, a feature reinforced by a higher difference between its reduction potential and that of its predecessor in the order of oxidation. We also showed that K43 and K52 mutants keep the mechanistic features of PpcA by establishing preferential e2/H+ transfer pathways at lower reduction potential values than the wild-type protein, a property that can enable rational design of Gs strains with optimized extracellular electron transfer capabilities.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Identification of residues involved in allosteric signal transmission from amino acid binding site of pyruvate kinase muscle isoform 2

PKM2 is a rate-limiting enzyme in the glycolytic process and is involved in regulating tumor proliferation. Several amino acids (AAs) such as Asn, Asp, Val, and Cys have been shown to bind to the AA binding pocket of PKM2 and modulate its oligomeric state, substrate binding affinity, and activity. Although previous studies have attributed that the main chain and side chain of bound AAs are responsible for initiating signal to regulate PKM2, the signal transduction pathway remains elusive. To identify the residues involved in signal transfer process, N70 and N75 located at two ends of a β strand connecting the active site and AA binding pocket were altered. Biochemical studies of these variants with various AA ligands (Asn, Asp, Val, and Cys), illustrate that N70 and N75, along with β1 connecting these residues are part of the signal transduction pathway between the AA binding pocket and the active site. The results demonstrate that mutation of N70 to D prevents the transfer of the inhibitory signal mediated by Val and Cys, whereas N75 to L alteration blocks the activating signal initiated by Asn and Asp. Taken together, this study confirms that N70 is one of the residues responsible for transmitting the inhibitory signal and N75 is involved in the activation signal flow.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Strategies for mitigating residual magnetic field effect on pre-production PIP-II SSR2 cryomodule performance

This paper outlines the strategy aimed at mitigating the adverse effects of residual magnetic fields on the performance of pre-production SSR2 superconducting cavities within the context of the PIP-II project at Fermilab. Residual magnetic fields can significantly impact cavity performance, leading to reduced quality factor. To address this challenge, our strategy integrates various approaches including magnetic shielding, careful selection of materials, quality controls aimed at measuring magnetic permeability, magnetic hygiene to reduce residual magnetic field at the installation phase. Additionally, experimental studies are being planned to analyze the behavior of the cavities under different magnetic field conditions, and the effectiveness of advanced demagnetization procedures.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Residual Dose and Environmental Monitoring for the Fermilab Main Injector Tunnel Using the Data Acquisition Logging Engine (Dale)

The Recycler and the Main Injector are part of the Fermilab Accelerator complex used to deliver proton beam to the different experiments. It is very important to control and minimize losses in both machines during operation, to reduce personnel dose from residual activation and to preserve component lifetime. To minimize losses, we need to identify the loss points and adjust the components accordingly. The Data Acquisition Loss Engine (DALE) platform has been developed within the Main Injector department and upgraded throughout the years. DALE is used to survey the entire enclosure for residual dose rates and environmental readings when unrestricted access to the enclosure is possible. Currently DALE has two radiation meters, which are aligned along each machine, so loss points can be identified for both at the same time. DALE attaches to the enclosure carts and is continuously in motion monitoring dose rates and other environmental readings. In this paper we will describe how DALE is used to provide radiation maps of the residual dose rates in the enclosure. We will also compare the loss points with the Beam Loss monitor data.

43 PARTICLE ACCELERATORS↗
DOE OSTI2012

A C. elegans -Based Foam for Rapid On-Site Detection of Residual Live Virus

In the response to and recovery from a critical homeland security event involving deliberate or accidental release of biological agents, initial decontamination efforts are necessarily followed by tests for the presence of residual live virus or bacteria. Such 'clearance sampling' should be rapid and accurate, to inform decision makers as they take appropriate action to ensure the safety of the public and of operational personnel. However, the current protocol for clearance sampling is extremely time-intensive and costly, and requires significant amounts of laboratory space and capacity. Detection of residual live virus is particularly problematic and time-consuming, as it requires evaluation of replication potential within a eukaryotic host such as chicken embryos. The intention of this project was to develop a new method for clearance sampling, by leveraging Sandia's expertise in the biological and material sciences in order to create a C. elegans -based foam that could be applied directly to the entire contaminated area for quick and accurate detection of any and all residual live virus by means of a fluorescent signal. Such a novel technology for rapid, on-site detection of live virus would greatly interest the DHS, DoD, and EPA, and hold broad commercial potential, especially with regard to the transportation industry.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2013

Workshop Report on Atomic Bomb Dosimetry--Residual Radiation Exposure: Recent Research and Suggestions for Future Studies

There is a need for accurate dosimetry for studies of health effects in the Japanese atomic bomb survivors because of the important role that these studies play in worldwide radiation protection standards. International experts have developed dosimetry systems, such as the Dosimetry System 2002 (DS02), which assess the initial radiation exposure to gamma rays and neutrons but only briefly consider the possibility of some minimal contribution to the total body dose by residual radiation exposure. In recognition of the need for an up-to-date review of the topic of residual radiation exposure in Hiroshima and Nagasaki, recently reported studies were reviewed at a technical session at the 57th Annual Meeting of the Health Physics Society in Sacramento, California, 22-26 July 2012. A one-day workshop was also held to provide time for detailed discussion of these newer studies and to evaluate their potential use in clarifying the residual radiation exposures to the atomic-bomb survivors at Hiroshima and Nagasaki. Suggestions for possible future studies are also included in this workshop report.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2016

Determining the Release of Radionuclides from Tank 18F Waste Residual Solids: FY2016 Report

Pore water leaching studies were conducted on actual Savannah River Site (SRS) Tank 18F residual waste solids to support Liquid Waste tank closure efforts. A test methodology was developed during previous simulant testing to produce slurries of tank residual solids and grout-representative solids in grout pore water solutions (based on SRS groundwater compositions) with pH and E h values expected during the aging of the closed waste tank. The target conditions are provided below where the initial pore water has a reducing potential and a relatively high pH (Reducing Region II). The pore water is expected to become increasingly oxidizing with time (Oxidizing Region II) and during the latter stages of aging (Oxidizing Region III) the pH is expected to decrease. For the reducing case, tests were conducted with both unwashed and washed Tank 18F residual solids. For the oxidizing cases (Oxidizing Regions II and III), all samples were washed with simulated grout pore water solutions prior to testing, since it is expected that these conditions will occur after considerable pore water solution has passed through the system. For the reducing case, separate tests were conducted with representative ground grout solids and with calcium carbonate reagent, which is the grout phase believed to be controlling the pH. Ferrous sulfide (FeS) solids were also added to the reducing samples to lower the slurry E h value. Calcium carbonate solids were used as the grout-representative solid phase for each of the oxidizing cases. Air purge-gas with and without CO 2 removed was transferred through the oxidizing test samples and nitrogen purge-gas was transferred through the reducing test samples during leach testing. The target pH values were achieved to within 0.5 pH units for all samples. Leaching studies were conducted over an E h range of approximately 0.7 V. However, the highest and lowest E h values achieved of ~+0.5 V and ~-0.2 V were significantly less positive and less negative, respectively, than the target values. Achievement of more positive and more negative E h values is believed to require the addition of non-representative oxidants and reductants, respectively.

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

Analysis of Corrosion Residues Collected from the Aluminum Basket Rails of the High-Burnup Demonstration Cask.

On September, 2015, an inspection was performed on the TN-32B cask that will be used for the high-burnup demonstration project. During the survey, wooden cribbing that had been placed within the cask eleven years earlier to prevent shifting of the basket during transport was removed, revealing two areas of residue on the aluminum basket rails, where they had contacted the cribbing. The residue appeared to be a corrosion product, and concerns were raised that similar attack could exist at more difficult-to-inspect locations in the canister. Accordingly, when the canister was reopened, samples of the residue were collected for analysis. This report presents the results of that assessment, which determined that the corrosion was due to the presence of the cribbing. The corrosion was associated with fungal material, and fungal activity likely contributed to an aggressive chemical environment. Once the cask has been cleaned, there will be no risk of further corrosion.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Waste to Wisdom: Utilizing Forest Residues for the Production of Bioenergy and Biobased Products

The Waste to Wisdom project was part of the Biomass Research and Development Initiative (BRDI) and funded by the Department of Energy (DE-EE0006297) at an amount of $5.8 million. Our interdisciplinary research team, consisting of academics, business professionals, and land managers, worked together for about four years (September 2013 to December 2017) to: 1) conduct field-based experiments to develop innovative tools and systems that improve the economics, accessibility, and production of quality feedstocks from forest residues, 2) develop and test stand-alone in-woods or near-the forest biomass conversion technologies (BCTs) for the production of biochar, torrefied wood, and briquettes, and 3) perform analyses to evaluate the economic feasibility of commercial deployment of BCTs and to quantify the life cycle economic and environmental benefits of utilizing forest residues with BCTs for the production of bioenergy and bioproducts. The research papers presented in this Special Issue cover key aspects of the research efforts and findings made by the project team. We encourage the audience to visit the project web site (http://wastetowisdom.com/) to learn more about the team’s research on feedstock development, biomass conversion technologies, and the financial and environmental benefits of utilizing forest residues for production of bioenergy and biobased products.

09 BIOMASS FUELS↗
DOE OSTI2019

Activation and residual dose rates in the NSLS-II storage ring

It is well known that components in high energy accelerators may get activated and expose workers during maintenance activities. While the potential for activation is higher in positive ion accelerators due to the prolific production of neutrons, certain regions and components in high energy electron accelerators too can be activated enough to create residual dose rates that require careful attention for ALARA compliance. In this report, the activation and residual dose rates from a few materials are studied from various beam loss scenarios ranging from chronic point losses to intermittent real loss scenarios obtained from the operational parameters of the NSLS-II storage ring. FLUKA Monte Carlo radiation transport code is used to model the geometry, the time profile of the beam losses and score the resulting time evolution of the remnant activity and the residual dose rates.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Photoluminescence Spectroscopy to Determine Residual Stresses in Glass-to-Metal Seals

In components with two materials, such as glass-to-metal (GtM) seals, residual stress can reduce long-term reliability. Therefore, it is important to be able to accurately measure residual stress within these components. The residual stress can be from a large strain due to the mismatch of thermo-physical response of the two materials or a small strain due to stress and/or structural relaxation. Both modeling and experimental measurements were conducted on multiple GtM seals constructed with CGI 930 glass with purposely added alumina particles. The alumina particles have an established Cr fluorescence pattern and the shift in position of these peaks can accurately measure the strain of the alumina crystals. Photoluminescence spectroscopy (PLS) technique was utilized due to its non-destructive nature and high spatial resolution. PLS scans of these components were analyzed and compared to the models developed previously.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Residual Insoluble Solids Expected from Saltcake Dissolution

A review of previous SRS saltcake dissolution and characterization studies was performed to inform the analysis of the amount of residual insoluble solids that may result from saltcake dissolution. A realistic value covering most cases for the maximum volume of a settled layer of residual insoluble solids that would result from dissolution of a volume of saltcake was calculated as 0.08 mL/mL (8 vol%). Applying factors to account for dissolution test uncertainty and differences between in-tank settling and laboratory testing, the recommended value for a settled layer of residual insoluble solids that would result from dissolution of a volume of saltcake is 0.16 mL/mL (16 vol%). This should apply to dissolution of saltcake with typical minimal amounts of entrained sludge but may not apply to saltcake with significant sludge. As it is composed of primarily non-radioactive isotopes, the precipitated aluminum hydroxide material does not contribute to the heat load.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

Recommended Updates to Solubility Controls for Modeling Leaching of Technetium, Uranium, Neptunium, Plutonium, and Iodine from the Residual Waste Layer of Closed Savannah River Site High Level Waste Tanks

The objective of this report is to relate waste leaching experiments by the Savannah River National Laboratory (SRNL) to performance assessment modeling of release of several radionuclides from residual waste in closed high-level waste tanks. SRNL leached residual waste from Tanks 18F and 12H with solutions simulating the modeled evolution of pore fluids in residual waste layers of closed tanks through various stages of grout degradation. Tc-99, uranium isotopes, Np-237, plutonium isotopes, and I-129 were analyzed in the leachate multiple times over 90 days.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2023

Residual Strains in an Additively Processed Ni-based Superalloy Transpiration-Cooled Aerodynamic Leading Edge Structure using Neutron Diffraction

Selective Laser Melting (SLM) is a well-known additive manufacturing method based on a layer-by-layer building process that is capable of fabricating gas turbine Ni-based superalloy parts with complex and integrated cooling geometries that are typically not achievable using conventional casting methods. However, the impact of residual stress concentration on SLM component life is a concern. In this work, residual strains present at room temperature in an SLM Inconel 718 generic aerodynamic leading edge segment with transpiration cooling were investigated using neutron diffraction at Oak Ridge National Laboratory. This study reveals that areas of the part where complex cooling holes were printed exhibit residual tensile strains that can be detrimental to its integrity. The study paves the way for future studies of the design of cooling hole geometries and manufacturing parameters that achieve improved cooling while minimizing stress concentration effects.

Fouliard, Quentin↗
DOE OSTI2024

Lignin molecular weights of Populus trichocarpa residues after CELF pretreatment

Here we present a dataset of molecular weights of lignin from a woody energy crop (Populus trichocarpa) residues after a series of co-solvent enhanced lignocellulosic fractionation (CELF) pretreatment. The natural poplar variant GW-9947 from the Center for Bioenergy Innovation (CBI) was used. The poplar was knife milled and passed through a 1 mm sieve and CELF pretreatment was performed in a Parr autoclave reactor with 7.5 wt % solids loading, 0.5 wt% H2SO4 as catalyst at 150°C with various time. Tetrahydrofuran was added in a 1:1 mass ratio with water as the pretreatment solvent. Lignin was isolated from the pretreated samples after ball-milling in a porcelain jar with ceramic balls via Retsch PM 200 at 580 rpm for 2.5 h followed by enzymatic hydrolysis in acetate buffer (pH 4.8, 50 °C) for 48 h. The solid residue was isolated by centrifugation and hydrolyzed again with freshly added buffer and enzymes for another 48 h. After filtration, the solid residue was extracted twice with 96% (v/v) 1,4-dioxane/water mixture at room temperature overnight. The extracts were combined, rotary evaporated, and freeze-dried to recover lignin. The lignin samples were then derivatized in an acetic anhydride/pyridine (1:1, v/v) mixture and stirred at room temperature for 24 h. Ethanol was added to the reaction mixture, left for 30 min and then removed with a rotary evaporator. The addition and removal of ethanol was repeated at least 3 times until all traces of acetic acid were removed. Acetylated lignin samples were then dissolved in tetrahydrofuran (THF) at a concentration of 1.0 mg/mL. The molecular weight of acetylated lignin was measured by a gel permeation chromatography (GPC) on a PSS-Polymer Standards Service (Warwick, RI, USA) GPC SECurity 1200 system featuring Agilent HPLC 1200 components equipped with four Waters Styragel columns (HR1, HR2, HR4 and HR6) and an UV detector (270 nm). Tetrahydrofuran was used as the mobile phase and flow rate was 0.3 mL/min. The Polymer Standards Service WinGPC Unity software (Build 6807) was used for data processing for all the samples. The data provides information about the effects of CELF pretreatment time at 150 ºC on lignin molecular weights.

09 BIOMASS FUELS↗
DOE OSTI2024

Heteronuclear single quantum coherence (HSQC) NMR spectra of lignin isolated from switchgrass residues after fermentation with milling

Here we present a curated dataset of two-dimensional heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectra of lignin isolated from a herbaceous energy crop (Panicum virgatum L.). The lowland variant “Timber” switchgrass from Ernst seeds was used. The switchgrass was knife milled and passed through a 2 mm sieve prior to consolidated bioprocessing (CBP) process. Switchgrass was suspended in Milli-Q water and autoclaved for 90 min on liquid cycles. The residues after autoclaving were then subjected to CBP using coculture of Clostridium thermocellum (C. thermocellum DSM 1313 (LL1004)) and Thermoanaerobacterium thermosaccarolyticum ( T. thermosaccharolyticum HG-8 ATCC 31960 (LL1244)). Once-fermented and twice-fermented (FF) switchgrass were subjected to ball and disc milling in bioreactors at 55 °C and 60, 48 grams/L solids loadings for primary and secondary fermentation respectively. When fermentations were completed, the residual solids were rinsed with milli-Q water. Lignin was isolated from the pretreated residues after ball-milling in a porcelain jar with ceramic balls via Retsch PM 200 at 600 rpm for 2 h followed by enzymatic hydrolysis in acetate buffer (pH 4.8, 50 °C) for 48 h. The dry lignin samples were dissolved in deuterated dimethyl sulfoxide (d6) and characterized using 13C–1H HSQC in a Bruker Avance III HD 500-MHz NMR spectrometer. A standard Bruker pulse sequence (hsqcetgpsisp.2) was used on a Prodigy platform cryoprobe. The spectra were acquired with the following acquisition conditions: 230 ppm spectral width in F1 (13C) dimension with 256 data points and 12 ppm spectral width in F2 (1H) dimension with 2048 data points, a 90° pulse, with a C–H coupling constant of 145 Hz, a 1.0 s pulse delay, and 64 scans. Spectra were processed using the Bruker TopSpin 3.6 software.

Lignin, HSQC, Switchgrass, CBP , Ball mill, Disc m↗