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At least 325 records · Page 18

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DOE OSTI2016

AGR-1 Compact 4-1-1 Post-Irradiation Examination Results

Destructive post-irradiation examination was performed on AGR-1 fuel Compact 4-1-1, which was irradiated to a final compact-average burnup of 19.4% FIMA (fissions per initial metal atom) and a time-average, volume-average temperature of 1072°C. The analysis of this compact focused on characterizing the extent of fission product release from the particles and examining particles to determine the condition of the kernels and coating layers. The work included deconsolidation of the compact and leach-burn-leach analysis, visual inspection and gamma counting of individual particles, metallurgical preparation of selected particles, and examination of particle cross-sections with optical microscopy, electron microscopy, and elemental analysis. Deconsolidation-leach-burn-leach (DLBL) analysis revealed no particles with failed TRISO or failed SiC layers (as indicated by very low uranium inventory in all of the leach solutions). The total fractions of the predicted compact inventories of fission products Ce-144, Cs-134, Cs-137, and Sr-90 that were present in the compact outside of the SiC layers were <2×10 -6 , based on DLBL data. The Ag-110m fraction in the compact outside the SiC layers was 3.3×10 -2 , indicating appreciable release of silver through the intact coatings and subsequent retention in the OPyC layers or matrix. The Eu-154 fraction was 2.4×10 -4 , which is equivalent to the inventory in one average particle, and indicates a small but measurable level of release from the intact coatings. Gamma counting of 61 individual particles indicated no particles with anomalously low fission product retention. The average ratio of measured inventory to calculated inventory was close to a value of 1.0 for several fission product isotopes (Ce-144, Cs-134, and Cs-137), indicating good retention and reasonably good agreement with the predicted inventories. Measured-to-calculated (M/C) activity ratios for fission products Eu-154, Eu-155, Ru-106, Sb-125, and Zr-95 were significantly less than 1.0. However, as no significant release of these fission products from compacts was noted during previous analysis of the AGR-1 capsule components, the low M/C ratios are most likely an indication of a bias in the inventories predicted by physics simulations of the AGR-1 experiment. The distribution of Ag-110m M/C ratios was centered on a value of 1.02 and was fairly broad (standard deviation of 0.18, with values as high as 1.42 and as low as 0.68). Based on all data gathered to date, it is believed that silver retention in the particles was on average relatively high, but that the broad distribution in values among the particles represents significant variation in the inventory of Ag-110m generated in the particles. Ceramographic analysis of particle cross-sections revealed many of the characteristic microstructures often observed in irradiated AGR-1 particles from other fuel compacts. Palladium-rich fission product clusters were observed in the IPyC and SiC layers near the IPyC-SiC interface of three Compact 4-1-1 particle cross-sections. In spite of the presence of fission product clusters in the SiC layer, no significant corrosion or degradation of the layer was observed in any of the particles examined.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2016

Final Progress Report for Grant Number DE-SC0007229

We exploited a novel spectrophotometer where the cuvette is a reflecting cavity completely filled with an absorbing suspension of live, intact bacteria to monitor the in situ absorbance changes in bacteria as they respired aerobically on soluble ferrous ions. Our prior observations suggested the following hypothesis: acidophilic bacteria that belong to different phyla express different types of electron transfer proteins to respire on extracellular iron. We tested this hypothesis using six different organisms that represented each of the six phyla of microorganisms that respire aerobically on iron. Each of these six organisms expressed spectrally different biomolecules that were redox-active during aerobic respiration on iron. In all six cases, compelling kinetic evidence was collected to indicate that the biomolecules in question were obligatory intermediates in their respective respiratory chains. Additional experiments with intact Acidithiobacillus ferrooxidans revealed that the crowded electron transport proteins in this organism’s periplasm constituted a semi-conducting medium where the network of protein interactions functioned in a concerted fashion as a single ensemble. Thus the molecular oxygen-dependent oxidation of the multi-center respiratory chain occurred with a single macroscopic rate constant, regardless of the proteins’ individual redox potentials or their putative positions in the aerobic iron respiratory chain.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2017

Thermal Analysis of Disposal of High-Level Nuclear Waste in a Generic Bedded Salt repository using the Semi-Analytical Method.

An example case is presented for testing analytical thermal models. The example case represents thermal analysis of a generic repository in bedded salt at 500 m depth. The analysis is part of the study reported in Matteo et al. (2016). Ambient average ground surface temperature of 15°C, and a natural geothermal gradient of 25°C/km, were assumed to calculate temperature at the near field. For generic salt repository concept crushed salt backfill is assumed. For the semi-analytical analysis crushed salt thermal conductivity of 0.57 W/m-K was used. With time the crushed salt is expected to consolidate into intact salt. In this study a backfill thermal conductivity of 3.2 W/m-K (same as intact) is used for sensitivity analysis. Decay heat data for SRS glass is given in Table 1. The rest of the parameter values are shown below. Results of peak temperatures at the waste package surface are given in Table 2.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2017

Method for modeling the gradual physical degradation of a porous material

Cementitious and other engineered porous materials encountered in waste disposals may degrade over time due to one or more mechanisms. Physical degradation may take the form of cracking (fracturing) and/or altered (e.g. increased) porosity, depending on the material and underlying degradation mechanism. In most cases, the hydraulic properties of degrading materials are expected to evolve due to physical changes occurring over roughly the pore to decimeter scale, which is conducive to calculating equivalent or effective material properties. The exact morphology of a degrading material in its end-state may or may not be known. In the latter case, the fully-degraded condition can be assumed to be similar to a more-permeable material in the surrounding environment, such as backfill soil. Then the fully-degraded waste form or barrier material is hydraulically neutral with respect to its surroundings, constituting neither a barrier to nor conduit for moisture flow and solute transport. Unless the degradation mechanism is abrupt, a gradual transition between the intact initial and fully-degraded final states is desired. Linear interpolation through time is one method for smoothly blending hydraulic properties between those of an intact matrix and those of a soil or other surrogate for the end-state.

36 MATERIALS SCIENCE↗

DOE OSTI2017

E-Area Low-Level Waste Facility Vadose Zone Model: Confirmation of Water Mass Balance for Subsidence Scenarios

In preparation for the next revision of the E-Area Low-Level Waste Facility (LLWF) Performance Assessment (PA), a mass balance model was developed in Microsoft Excel to confirm correct implementation of intact- and subsided-area infiltration profiles for the proposed closure cap in the PORFLOW vadose-zone model. The infiltration profiles are based on the results of Hydrologic Evaluation of Landfill Performance (HELP) model simulations for both intact and subsided cases.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2017

E-Area LLWF Vadose Zone Model: Probabilistic Model for Estimating Subsided-Area Infiltration Rates

A probabilistic model employing a Monte Carlo sampling technique was developed in Python to generate statistical distributions of the upslope-intact-area to subsided-area ratio (Area UAi /Area SAi ) for closure cap subsidence scenarios that differ in assumed percent subsidence and the total number of intact plus subsided compartments. The plan is to use this model as a component in the probabilistic system model for the E-Area Performance Assessment (PA), contributing uncertainty in infiltration estimates.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2015

Milestone report - M4FT-15OR03120210 - Multi-lab Analytical Plan for Analysis of Legacy 85 Kr Samples

Legacy samples composed of 85 Kr encapsulated in solid zeolite 5A material and five small metal tubes containing a mixture of the zeolite combined with a glass matrix resulting from hot isostatic pressing have been preserved. The samples were a result of krypton R&D encapsulation efforts in the late 1970s performed at the Idaho Chemical Processing Plant. These samples were shipped to Oak Ridge National Laboratory (ORNL) in mid-FY 2014. Upon receipt the outer shipping package was opened and the inner package removed and placed in a radiation hood. The individual capsules were double bagged as they were removed from the inner shipping pig and placed into individual glass sample bottles for further analysis. The five capsules were then x-ray imaged. Capsules 1 and 4 appear to contain an amorphous mass within the capsules. Capsule 2 clearly shows the saw marks on the capsule and a quantity of loose pellet or bead-like material remaining in the capsule. Capsule 3 shows similar bead-like material within the intact capsule. Capsule 5 was previously opened. The end of this capsule appears to have been cut off and there are additional saw marks on the side of the capsule. X-ray tomography allowed the capsules to be viewed along the three axes. Of most interest was determining whether there was any residual material in the closed end of Capsule 5. The images confirmed the presence of residual material within this capsule. The material appears to be compacted but still retains some of the bead-like morphology. A conference call was held on February 19, 2015, with participation from ORNL, Idaho National Laboratory, Sandia National Laboratories, and Pacific Northwest National Laboratory Sigma Team members. The nondestructive analysis (NDA) results were discussed, and a proposed path forward was formulated to advance this effort toward the original goals of understanding the effects of extended storage on the waste form and package. Based on the initial NDA and the fact that there are at least two breached samples it was proposed that exploratory tests be conducted with the breached specimens before opening the three intact capsules. Portions of these would be analyzed to determine the fraction of krypton/xenon remaining in the matrix and the amount of rubidium remaining in the matrix. The inner surface of the breached capsules would be examined for corrosion.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2018

Determining the Impact of Forest Mortality in Semi-Arid Woodlands on Local and Regional Carbon Dynamics

We received funds in July 2012, and with supplemental funds, this funding ended in July 2017. Our overall project goals were to quantify the consequences of pinon mortality for carbon, water and energy exchange in pinon-juniper woodlands. To do this, we have been continuously measuring carbon, water and energy exchange using eddy covariance, over two pinon-juniper woodlands in central New Mexico. In one site, we girdled 1632 trees in the 4 ha surrounding the tower in Sept 2009. The other site, only 5 km away on the same plateau, was left intact, to serve as a control. We used this paired tower approach so we could directly evaluate the differences between how fluxes from disturbed and intact woodlands respond to the exact same climate conditions. In addition to eddy covariance measured fluxes from the two woodlands, we also made sap flux measurements, biomass, gas exchange, and soil respiration fluxes simultaneously in the two sites. The overall objective of this proposal is to measure the carbon and climate forcing consequences of widespread coniferous mortality events in the Southwestern US.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2018

Potential Research and Development Opportunities for Light Water Reactor Spent Nuclear Fuel at INL

This report documents the commercial spent nuclear fuel currently in storage at Idaho National Laboratory with a specific focus on the potential research and development (R&D) opportunities for this material. Commercial spent nuclear fuel is stored in dry casks on the INL site at the Idaho Nuclear Technology and Engineering Center (INTEC, formerly the Idaho Chemical Processing Plant or ICPP). This spent fuel was part of the DOE-industry cooperative dry cask demonstration project that began in 1983 and from historical fuel testing and treatment activities that had been performed at the Test Area North (TAN)-607 facility. Most of the fuel is “low burnup,” but given that it was removed from the respective reactors between 1970 and 1985, it was representative for its time. The majority of the fuel is of the 15×15 Westinghouse PWR variety, though additional fuel types (e.g., TN-BRP) and configurations are also stored. Potential R&D opportunities identified are (1) the REA-2023 cask, (2) the TN-BRP cask, and (3) the Castor V/21 cask. Fuel from the TN-24P may be an alternative to the intact assemblies in the Castor V/21. Specifically, the REA-2023 cask contains 9 rods that have been exposed to air since 2005. These rods have a detailed pre-loading characterization and thus any changes in corrosion or geometry can most likely be attributed to the storage environment. In addition, similar rods to the nine in REA-2023 reside in the Castor V/21 cask whose environment has been maintained with inert nitrogen. The Castor V/21 cask also contains intact PWR assemblies that could be used to perform limited confirmation of the pyroprocessing approach. An alternative to the use of the Castor assemblies for pyroprocessing is the consolidated fuel that is stored in the TN-24P, which would not require removal from the assembly grid since it has already been packaged in accessible two-piece shell strongback containers. The TN-BRP cask contains a number of Gd-doped, low burnup assemblies that could be of use to validate code packages used to justify burnup-up credit for boiling water reactors (BWRs). The INL dry casks are stored on the CPP-2707 pad at INTEC, adjacent to the CPP-603 Irradiated Fuel Storage Facility, which incorporates a dry hot cell that has the potential to receive a full scale commercial cask of the types identified. Several evaluations have been made regarding this task, including full scale mockup testing of the physical clearances required to remove and handle fuel assemblies and components. A proposed schedule of 14 months and cost of $5.3 million was the outcome of analysis performed by Fluor Idaho and is included as Appendix A & B. In addition to the spent fuel at INL, there is also a full-scale mockup assembly that was fabricated for the Protypical Consolidation Demonstration Project to validate fuel rod consolidation approaches. The assembly was fabricated by Westinghouse as a 15 x 15 PWR, using Zircaloy-4 tubing and steel end fittings in accordance with product specifications. The only departure from specification is the use of copper metal in lieu of uranium oxide pellets to achieve a weight that is within 10% of the standard.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2021

Proposed Risk-Informed Regulatory Framework for Approval of Microreactor Transportation Packages

Microreactors are very small nuclear reactors with a power output of about 20 megawatts electric or less that are designed to be factory-built, modular in nature, and highly portable. These compact reactors will be small enough to be transported by truck or even air and could help solve energy challenges in a number of areas, ranging from remote commercial or residential locations to military bases. Pacific Northwest National Laboratory is tasked to develop and evaluate transportation licensing options for microreactors. The work is funded by the National Reactor Innovation Center a National Department of Energy program led by Idaho National Laboratory for the Office of Nuclear Energy Research and Development which support demonstration of microreactor technology. Key transportation steps include the (1) initial movement of high-assay low enriched uranium fresh fuel, (2) transportation of an intact, but never-operated microreactor, and (3) transportation of an intact, previously-operated microreactor. The deliverables on the project consists of a documentation of applicable regulations and regulatory authority for transportation. The objective of this report is to propose a risk-informed regulatory framework for the licensing of the transportation of microreactors, including the transportation of irradiated nuclear fuel that is assumed to be an integral component of the microreactor transportation package. The framework lays out a viable regulatory pathway, including decision points for regulatory options and the supporting technical evaluations for those options in phases from near to long term. This report includes discussion of the (1) general microreactor design concepts including representative microreactor source terms, (2) options for regulatory approval of microreactor transportation based on current regulation and historical precedence, (3) regulatory basis for including risk information in microreactor transportation licensing activities, and (4) description of a risk-informed regulatory framework.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2021

Proposed Risk-Informed Regulatory Framework for Approval of Microreactor Transportation Packages

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2024

Dissolution Flowsheet for Non-Aluminum Spent Nuclear Fuel Campaign 1

As part of the Accelerated Basin De-inventory (ABD) program, H Canyon plans to dissolve non-aluminum spent nuclear fuel (NASNF) in the 6.3D electrolytic dissolver. NASNF Campaign 1 plans to electrolytically dissolve 68 bundles of fuel assemblies from the Carolinas-Virginia Tube Reactor (CVTR), Heavy Water Components Test Reactor (HWCTR), and Experimental Boiling Water Reactor (EBWR). The fuel assemblies are intact Zircaloy or stainless steel (SS) clad UO 2 rods, tubes, and plates. The H Canyon electrolytic dissolver previously dissolved a variety of UO 2 core fuel types in SS, Zircaloy, Nichrome, or Incoloy cladding from 1969 to 1980. The objective of this study was to identify flowsheet conditions through literature review and laboratory experimentation to safely dissolve NASNF Campaign 1 bundles in the H Canyon electrolytic dissolver. Bench-scale electrolytic dissolution tests were performed to demonstrate a flowsheet for NASNF Campaign 1 bundles. The outer bundles are composed of SS or Al alloy, Al 6061-T6, and contain intact Zircaloy or SS clad UO 2 fuel assemblies. The key objectives of these tests were to determine bounding dissolver chemistries and the sparge requirement to ensure H 2 concentration remain less than 60 vol % of the lower flammability limit (LFL) during dissolution. The impact of HNO 3 concentration and the addition of fluoride on the dissolution efficiency of Zircaloy, 304L SS, Al 6061-T6, and Inconel 625 were examined. While SS, Al, and Inconel 625 readily dissolve utilizing electrolytic dissolution, Zircaloy disintegrated anodically; the surface of Zircaloy oxidized and the oxide layer spalled off and settled at the bottom of the dissolver as an insoluble material. The black flakes were identified as ZrO 2 and 85% of the Zr processed was converted to black ZrO 2 flakes when Zr was anodically disintegrated in 9.5 M HNO 3 .

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2023

Developing Methods to Assess Changes in Mechanical Properties of Shale Modified by Engineered Mineral Precipitation

Fractures in subsurface shale formations serve multiple purposes, for example, in the recovery of resources in hydraulic fracturing or as potential harmful leakage passages through caprocks that may contribute undesired fluids to the atmosphere or functional groundwater aquifers. A proposed method to seal or influence fracture properties is Ureolysis-Induced Calcium Carbonate Precipitation (UICP), a bio-mineralization technology driven by the enzymatic hydrolysis of urea, resulting in the formation of calcium carbonate. Sporosarcina pasteurii is a common microbe used as the source of the urease enzyme that catalyzes the chemical reaction. The resulting calcium carbonate can bridge the gaps in fractured shale and reduce fluid flow through fractures. However, there is little information on how this process affects the mechanical properties of the resulting biomineralized shale. This study represents the first step toward determining the influence of UICP treatment on shale material and its subsequent mechanical strength properties. This methods development study aims to determine the effect that temperature has on the tensile strength of intact, unfractured shale cores (2.54 cm (1 in) diameter, 5.08 cm (2 in) long). Tensile strength was determined indirectly using a modified Brazilian test where the splitting tensile strength is attained by applying a compressive load onto the core. Shale cores from Eagle Ford and Wolfcamp formations were tested at both room temperature and 60°C to determine if increased temperature influences the tensile strength of the rock. This data will help to assess the necessity of testing biomineralized cores at temperature. Though 60°C may not mimic subsurface temperatures of the shales used in this study, it was chosen due to limitations of the UICP process while still approaching temperatures of shale formations. This project aims to evaluate what effect temperature has on the mechanical properties of intact shale cores so that engineered or natural rock fractures that are sealed by biomineralization can be better understood.

Bedey, Kayla↗

DOE OSTI2019

Recognition of Peptidoglycan Fragments by the Transpeptidase PBP4 From Staphylococcus aureus

Peptidoglycan (PG) is an essential component of the cell envelope, maintaining bacterial cell shape and protecting it from bursting due to turgor pressure. The monoderm bacterium Staphylococcus aureus has a highly cross-linked PG, with ~90% of peptide stems participating in DD-cross-links and up to 15 peptide stems connected with each other. These cross-links are formed in transpeptidation reactions catalyzed by penicillin-binding proteins (PBPs) of classes A and B. Most S. aureus strains have three housekeeping PBPs with this function (PBP1, PBP2, and PBP3) but MRSA strains have acquired a third class B PBP, PBP2a, which is encoded by the mecA gene and required for the expression of high-level resistance to β-lactams. Another housekeeping PBP of S. aureus is PBP4, which belongs to the class C PBPs, and hence would be expected to have PG hydrolase (DD-carboxypeptidase or DD-endopeptidase) activity. However, previous works showed that, unexpectedly, PBP4 has transpeptidase activity that significantly contributes to both the high level of cross-linking in the PG of S. aureus and to the low level of β-lactam resistance in the absence of PBP2a. To gain insights into this unusual activity of PBP4, we studied by NMR spectroscopy its interaction in vitro with different substrates, including intact peptidoglycan, synthetic peptide stems, muropeptides, and long glycan chains with uncross-linked peptide stems. PBP4 showed no affinity for the complex, intact peptidoglycan or the smallest isolated peptide stems. Transpeptidase activity of PBP4 was verified with the disaccharide peptide subunits (muropeptides) in vitro, producing cyclic dimer and multimer products; these assays also showed a designed PBP4(S75C) nucleophile mutant to be inactive. Using this inactive but structurally highly similar variant, liquid-state NMR identified two interaction surfaces in close proximity to the central nucleophile position that can accommodate the potential donor and acceptor stems for the transpeptidation reaction. A PBP4:muropeptide model structure was built from these experimental restraints, which provides new mechanistic insights into mecA independent resistance to β-lactams in S. aureus.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2020

Mapping Influenza-Induced Posttranslational Modifications on Histones from CD8+ T Cells

T cell function is determined by transcriptional networks that are regulated by epigenetic programming via posttranslational modifications (PTMs) to histone proteins and DNA. Bottom-up mass spectrometry (MS) can identify histone PTMs, whereas intact protein analysis by MS can detect species missed by bottom-up approaches. We used a novel approach of online two-dimensional liquid chromatography-tandem MS with high-resolution reversed-phase liquid chromatography (RPLC), alternating electron transfer dissociation (ETD) and collision-induced dissociation (CID) on precursor ions to maximize fragmentation of uniquely modified species. The first online RPLC separation sorted histone families, then RPLC or weak cation exchange hydrophilic interaction liquid chromatography (WCX-HILIC) separated species heavily clad in PTMs. Tentative identifications were assigned by matching proteoform masses to predicted theoretical masses that were verified with tandem MS. We used this innovative approach for histone-intact protein PTM mapping (HiPTMap) to identify and quantify proteoforms purified from CD8 T cells after in vivo influenza infection. Activation significantly altered PTMs following influenza infection, histone maps changed as T cells migrated to the site of infection, and T cells responding to secondary infections had significantly more transcription enhancing modifications. Thus, HiPTMap identified and quantified proteoforms and determined changes in CD8 T cell histone PTMs over the course of infection.

mass spectrometry↗

DOE OSTI2025

A Wind-driven Origin for the Firework Morphology of the Supernova Remnant Pa 30

Pa 30—the likely remnant of the Galactic Type Iax supernova of 1181 AD—displays an unusual, firework-like morphology, consisting of radial filaments extending from a common center, where a white dwarf (WD) currently drives a very fast wind (speed ≳10 4 km s −1 ). We propose the filaments arose from the Rayleigh–Taylor-unstable nature of the interface between the circumstellar medium (CSM) and the shocked wind launched by the natal WD; the filaments then elongated intact due to the Kelvin–Helmholtz-stable nature of the large initial density contrast between the wind and CSM, supplemented by the slowly declining wind density profile (relative to homologously expanding ejecta). To support this interpretation, we present two-dimensional hydrodynamical simulations and derive the filament properties, including their speed, density, and temperature, all of which are consistent with observations. We suggest the filaments elongate until the wind and CSM densities become comparable at the contact discontinuity, which occurs within 1–10 yr, and then truncate because the Rayleigh–Taylor instability (RTI) halts. The subsequent Kelvin–Helmholtz instability growth timescale across the current width of the filaments is longer than the age of Pa 30, so they remain intact. The filament-less central region in Pa 30 is therefore more likely a consequence of the finite timescale over which the RTI operates, rather than a wind termination shock. In general, firework-like filaments may form in other systems, provided there is a sufficiently large density contrast between the ejecta and its surroundings.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2013

Improved Method for Isolation of Microbial RNA from Biofuel Feedstock for Metatranscriptomics

Metatranscriptomics—gene express profiling via DNA sequencing—is a powerful tool to identify genes that are ac- tively expressed and might contribute to the phenotype of individual organisms or the phenome (the sum of several phenotypes) of a microbial community. Furthermore, metatranscriptome studies can result in extensive catalogues of genes that encode for enzymes of industrial relevance. In both cases, a major challenge for generating a high quality metatranscriptome is the extreme lability of RNA and its susceptibility to ubiquitous RNAses. The microbial commu- nity (the microbiome) of the cow rumen efficiently degrades lignocelullosic biomass, generates significant amounts of methane, a greenhouse gas twenty times more potent than carbon dioxide, and is of general importance for the physio- logical wellbeing of the host animal. Metatranscriptomes of the rumen microbiome from animals kept under different conditions and from various types of rumen-incubated biomass can be expected to provide new insights into these highly interesting phenotypes and subsequently provide the framework for an enhanced understanding of this socio- economically important ecosystem. The ability to isolate large amounts of intact RNA will significantly facilitate accu- rate transcript annotation and expression profiling. Here we report a method that combines mechanical disruption with chemical homogenization of the sample material and consistently yields 1 mg of intact RNA from 1 g of rumen-in- cubated biofuel feedstock. The yield of total RNA obtained with our method exceeds the RNA yield achieved with pre- viously reported isolation techniques, which renders RNA isolated with the method presented here as an ideal starting material for metatranscriptomic analyses and other molecular biology applications that require significant amounts of starting material.

Environmental Molecular Sciences Laboratory↗

DOE OSTI2023

Developing Methods to Assess Changes in Mechanical Properties of Shale Modified by Engineered Mineral Precipitation

clastic rock↗