gismo-cloud-deployment
Tools for executing time-consuming tasks with developer-defined custom code blocks in parallel on the AWS EKS platform.
Leu, Jimmy↗
SEARCH · Engineering Papers
Results for “LEU”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
HiPAS GridLAB-D
HiPAS GridLAB-D is the California Energy Commission (CEC) version of GridLAB-D.
Chassin, David P.↗
An African-Specific Variant of TP5 3 Reveals PADI4 as a Regulator of p53-Mediated Tumor Suppression
TP53 is the most frequently mutated gene in cancer, yet key target genes for p53-mediated tumor suppression remain unidentified. Here, we characterize a rare, African-specific germline variant of TP53 in the DNA-binding domain Tyr107His (Y107H). Nuclear magnetic resonance and crystal structures reveal that Y107H is structurally similar to wild-type p53. Consistent with this, we find that Y107H can suppress tumor colony formation and is impaired for the transactivation of only a small subset of p53 target genes; this includes the epigenetic modifier PADI4, which deiminates arginine to the nonnatural amino acid citrulline. Surprisingly, we show that Y107H mice develop spontaneous cancers and metastases and that Y107H shows impaired tumor suppression in two other models. We show that PADI4 is itself tumor suppressive and that it requires an intact immune system for tumor suppression. We identify a p53–PADI4 gene signature that is predictive of survival and the efficacy of immune-checkpoint inhibitors.
60 APPLIED LIFE SCIENCES↗
Elastic properties of type-I clathrate K 8 Zn 4 Sn 42 determined by inelastic X-ray scattering
We measured the phonon dispersion at ambient conditions in single-crystal type-I clathrate K8Zn4Sn42, a material with promising thermoelectric properties that has only recently been synthesized, using the high-energy resolution inelastic X-ray scattering (IXS) technique. From the sound velocities along high-symmetry directions, we extracted the elastic constants (C 11, C 12, C 44 = 63.2, 19.1, 21.9 GPa, respectively). Experimental results agree with the predictions from first-principles calculations on the hypothetical, "guest-free", type-I clathrate Sn46. The size of the crystal investigated was several orders of magnitude smaller than what is required for neutron and ultrasonic measurements. Due to this essential property, together with the high-energy resolution, high-momentum-transfer resolution, and the access to the strongest Bragg reflections, IXS is the technique of choice for measuring the full elastic constant tensor for microcrystals.
Leu, Bogdan M.↗
Expanded Validation of Uranium Systems with the KENO Monte Carlo Codes and SCALE 6.2.4
The development of accident-tolerant fuel and advanced reactors fueled with high-assay low-enriched uranium has created an increased focus on systems with uranium enrichments between 5 and 20 wt % 235 U. SCALE criticality safety validation reports generated at Oak Ridge National Laboratory contain very few benchmark experiments in this range. The work presented herein is an initial investigation of expanded validation of the entire range of enrichments for uranium-fueled systems, including consideration of over 300 newly developed KENO models. The vast majority of the new models are between 4.4 wt % and 37.5 wt % enrichment and include a variety of thermal, intermediate, and mixed neutron spectra. This work finds no strong evidence of an enrichment-dependent bias, but there are indications of a spectrum-dependent bias. There are, however, only a limited number of independent experiments included at this time to distinguish intermediate enrichment effects from intermediate spectrum effects. Further work in this area is ongoing for intermediate enrichment systems. In the long run, the addition of these models to the Verified, Archived Library and Inputs and Data is planned, as funding and staff availability allow.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Proposed Plutonium-Nickel Critical Experiment
The Los Alamos Critical Experiments Facility (LACEF) and subsequently its descendant, the National Criticality Experiments Research Center (NCERC) located at the Nevada National Security Site, have been performing critical experiments for over 75 years. The work done continues to build upon lessons learned from the past. It also builds upon knowledge gained from past experiments. The LACEF and NCERC experiments “provide nuclear criticality benchmark data for a wide variety of fissile and non-fissile materials in all neutron energy spectra systems”. In 2014, a subcritical benchmark with plutonium surrounded by nickel was issued in the International Criticality Safety Benchmark Evaluation Project (ICSBEP). Two years later, a new benchmark experiment was performed, commonly known as Subcritical Copper Reflected $\mathcal{a}$-Phase Plutonium SCR$\mathcal{a}$P. The uncertainties in the SCR$\mathcal{a}$P experiment were significantly reduced from the Pu-Ni experiment and the methods were refined. Additionally, a Pu-lead critical experiment was performed in 2017 which followed different methods and with different objectives. Now, an experiment is proposed that builds on both the subcritical nickel experiment and the critical lead experiment. The proposed experiment has interleaved nickel and plutonium, in a thermal arrangement. This particular experiment would support criticality safety at the Hanford Tank Farms, whose tanks contain a significant amount of nickel credited as a neutron absorber in the criticality safety evaluation.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Substrate-embedded metal meshes for ITO-free organic light emitting diodes
Organic light-emitting diodes (OLEDs) have great potential for use in large-area display and lighting applications, but their widespread adoption for large areas is hindered by the high cost and insufficient performance of indium tin oxide (ITO) anodes. In this study, we introduce an alternative anode material – a silver mesh embedded in glass – to facilitate production of large-area OLEDs. We present a facile, scalable manufacturing technique to create high aspect ratio micromeshes embedded in glass to provide the planar geometry needed for OLED layers. Our phosphorescent green OLEDs achieve a current efficiency of 51.4 cd/A at 1000 cd/m 2 and reach a slightly higher external quantum efficiency compared to a standard ITO/glass reference sample. Notably, these advancements are achieved without any impact on the viewing angle of the OLEDs. These findings represent a promising advancement towards ITO-free, high-efficiency OLEDs for various high performance, large-area applications, such as lighting and displays.
Optics↗
Comparative genomics reveals electron transfer and syntrophic mechanisms differentiating methanotrophic and methanogenic archaea
The anaerobic oxidation of methane coupled to sulfate reduction is a microbially mediated process requiring a syntrophic partnership between anaerobic methanotrophic (ANME) archaea and sulfate-reducing bacteria (SRB). Based on genome taxonomy, ANME lineages are polyphyletic within the phylum Halobacterota , none of which have been isolated in pure culture. Here, we reconstruct 28 ANME genomes from environmental metagenomes and flow sorted syntrophic consortia. Together with a reanalysis of previously published datasets, these genomes enable a comparative analysis of all marine ANME clades. We review the genomic features that separate ANME from their methanogenic relatives and identify what differentiates ANME clades. Large multiheme cytochromes and bioenergetic complexes predicted to be involved in novel electron bifurcation reactions are well distributed and conserved in the ANME archaea, while significant variations in the anabolic C1 pathways exists between clades. Our analysis raises the possibility that methylotrophic methanogenesis may have evolved from a methanotrophic ancestor.
59 BASIC BIOLOGICAL SCIENCES↗
Development of a Native Escherichia coli Induction System for Ionic Liquid Tolerance
The ability to solubilize lignocellulose makes certain ionic liquids (ILs) very effective reagents for pretreating biomass prior to its saccharification for biofuel fermentation. However, residual IL in the aqueous sugar solution can inhibit the growth and function of biofuel-producing microorganisms. In E. coli this toxicity can be partially overcome by the heterologous expression of an IL efflux pump encoded by eilA from Enterobacter lignolyticus. In the present work, we used microarray analysis to identify native E. coli IL-inducible promoters and develop control systems for regulating eilA gene expression. Three candidate promoters, PmarR’, PydfO’, and PydfA’, were selected and compared to the IPTG-inducible PlacUV5 system for controlling expression of eilA. The PydfA’ and PmarR’ based systems are as effective as PlacUV5 in their ability to rescue E. coli from typically toxic levels of IL, thereby eliminating the need to use an IPTG-based system for such tolerance engineering. We present a mechanistic model indicating that inducible control systems reduce target gene expression when IL levels are low. Selected-reaction monitoring mass spectrometry analysis revealed that at high IL concentrations EilA protein levels were significantly elevated under the control of PydfA’ and PmarR’ in comparison to the other promoters. Further, in a pooled culture competition designed to determine fitness, the strain containing pPmarR’-eilA outcompeted strains with other promoter constructs, most significantly at IL concentrations above 150 mM. These results indicate that native promoters such as PmarR’ can provide effective systems for regulating the expression of heterologous genes in host engineering and simplify the development of industrially useful strains.
59 BASIC BIOLOGICAL SCIENCES↗
Thermal Hydraulic Characteristics of Fuel Defects in Plate Type Nuclear Research Reactors
Turbulent flow coupled with heat transfer is investigated for a High Flux Isotope Reactor (HFIR) fuel plate. The Reynolds Averaged Navier-Stokes Models are used for fluid dynamics and the transfer of heat from a thermal nuclear fuel plate using the Multi-physics code COMSOL. Simulation outcomes are compared with experimental data from the Advanced Neutron Source Reactor Thermal Hydraulic Test Loop. The computational results for the High Flux Isotope Reactor core system provide a more physically accurate simulation of this system by modeling the turbulent flow field in conjunction with the diffusion of thermal energy within the solid and fluid phases of the model domain. Recommendations are made regarding Nusselt number correlations and material properties for future thermal hydraulic modeling efforts
COMSOL LEU HFIR↗
Simulating High Flux Isotope Reactor Core Thermal-Hydraulics via Interdimensional Model Coupling
A coupled interdimensional model is presented for the simulation of the thermal-hydraulic characteristics of the High Flux Isotope Reactor core at Oak Ridge National Laboratory. The model consists of two domains a solid involute fuel plate and the surrounding liquid coolant channel. The fuel plate is modeled explicitly in three-dimensions. The coolant channel is approximated as a twodimensional slice oriented perpendicular to the fuel plate s surface. The two dimensionally-inconsistent domains are linked to one another via interdimensional model coupling mechanisms. The coupled model is presented as a simplified alternative to a fully explicit, fully three-dimensional model. Involute geometries were constructed in SolidWorks. Derivations of the involute construction equations are presented. Geometries were then imported into COMSOL Multiphysics for simulation and modeling. Both models are described in detail so as to highlight their respective attributes in the 3D model, the pursuit of an accurate, reliable, and complete solution; in the coupled model, the intent to simplify the modeling domain as much as possible without affecting significant alterations to the solution. The coupled model was created with the goal of permitting larger portions of the reactor core to be modeled at once without a significant sacrifice to solution integrity. As such, particular care is given to validating incorporated model simplifications. To the greatest extent possible, the decrease in solution time as well as computational cost are quantified versus the effects such gains have on the solution quality. A variant of the coupled model which sufficiently balances these three solution characteristics is presented alongside the more comprehensive 3D model for comparison and validation.
COMSOL HFIR LEU↗
A Computational Approach and Experimental Validation for the Assessment of Added Mass for Fuel Plates
The goals of this study are to (1) determine the change in the fundamental frequency of the plate when submersed in a fluid and (2) asses the ability for the pseudo-solid approach to determine the fundamental of frequency of a plate in channels. For objective (1) a small experiment, frequency identification in a fluid experiment (FIFE), has been created for the purpose of determining the change in frequency of a plate from air to fluid to fluid channels. The experiment uses sound excitation as a driving frequency and the response is measured via strain gauge, complimented with a hydrophone and microphone. Experimental results have been obtained for both air and water. The experimental results are further used to validate the pseudo-solid approach to achieve objective (2). The pseudo-solid approach has shown excellent agreement with theoretical determinations of frequencies of bodies submersed in a fluid. This paper outlines the experimental results of the FIFE as well as the validity of the pseudo-solid method
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Conceptual Design Report for the Materials and Fuels Complex (MFC) Research Collaboration Building (RCB)
The objective of this Conceptual Design Report (CDR) is to provide conceptual design information and details for a facility that meets the DOE approved mission need statement and provides the basis for Critical Decision Equivalent (CDE)-1 approval by the DOE. The objective of the project is to create easily accessible research and collaboration space to house MFC and other external nuclear energy research personnel, dry laboratory space, and space for internal and external researchers to perform data analysis in support of experiments. The facility will be designed and space will be allocated for external nuclear energy researchers to train, work and collaborate with MFC researchers. A laboratory area will be designed and constructed to accomplish instrument development, benchtop fabrication, and prototyping in support of experiments and experimental equipment. The entire building will be a non-radiological facility.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Enhancement of Gas-Atomized 304L Stainless Steel Powder by Plasma Spheroidization for use in the Laser Powder Bed Fusion Process
Explore the source record for details and available documents.
Sehhat, M↗
Energy-dependent Bias between ENDF/B-VII.1 and ENDF/B-VIII.0 for LCT Benchmarks [Slides]
Abstract not provided.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Energy-dependent Bias between ENDF/B-VII.1 and ENDF/B-VIII.0 for LCT Benchmarks [Slides]
Abstract not provided.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
STTR Phase I: Microfluidic Printing of High Performance Microgrids for High Efficiency, Flexible Organic Light Emitting Diodes Technical Report
Electroninks has been approached, and received strong interest from customers including chemical companies, device integrators, and final device producers. We have gained substantial customer traction in diverse markets as detailed in our Phase I report, and are currently sampling customers in the US, as well as Asia which is where the consumer/industry electronics supply chain is primarily positioned. The results reported here combined with our customer traction to date encourage us to apply for the Phase II stage of this work with the goal to advance the commercialization of our metal grids and particle free conductive inks.
LeMieux, PhD, Melbs↗
PNNL's Characterization Summary for MP-2 Experiment
Characterization of as-fabricated fuel was performed at Pacific Northwest National Laboratory (PNNL) in accordance with the characterization plan for the fabrication of U 10Mo plate fuel for the U.S. High Performance Research Reactor conversion program’s Fuel Fabrication Pillar (INL 2021). Similar characterization work is also being performed at Idaho National Laboratory to provide a detailed understanding of the as-fabricated foils that would be irradiated in the Mini-Plate 2 (MP 2) experiment. Under the MP 2 characterization plan, foils are studied that have different fabrication parameters (such as rolling condition, rolling thickness reduction, co-rolling with Zr layers). Similar samples from master foils were sent to both the organizations, so that the testing and analysis can be done independently using similar equipment and standardized measurement and analysis procedures. A final, consolidated report will be prepared based on this work and will summarize all the information obtained from the two laboratories. The MP 2 experiment will provide an opportunity to understand the effects of processing conditions on the final fuel microstructure, to compare results obtained independently, and achieve a two-way validation. In Fiscal Year 2022, PNNL received five MP 2 cast (PD STD2) samples to examine the foils’ chemistry and microstructure. For each cast sample, PNNL received samples from three different locations. PNNL also received and characterized 24 U 10Mo foil samples, by sectioning four pieces/specimens from each foil, in accordance with the MP 2 Characterization Plan (INL 2021). These 24 samples consist of four types of foils from BWX Technologies: 0.047 in. thick hot-rolled and annealed samples with Zr layers; 0.025 in. thick cold-rolled and annealed samples with Zr layers; 0.0105 in. thick cold-rolled and annealed samples with Zr layers. Along with these, PNNL also received four plates with Zr layers that were 0.025 in. and 0.0105 in. thick. This report describes the results of PNNL’s MP 2 foil characterization. Microstructure, Mo homogeneity, carbide fraction and morphology, U 10Mo foil thickness, and Zr thickness were evaluated in both the longitudinal and transverse directions for all the foils of the three different thicknesses.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗