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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.
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Carboxylate-based molecular magnet: One path toward achieving stable quantum correlations at room temperature
The control of quantum correlations in solid-state systems by means of material engineering is a broad avenue to be explored, since it makes possible steps toward the limits of quantum mechanics and the design of novel materials with applications on emerging quantum technologies. This letter explores the potential of molecular magnets to be prototypes of materials for quantum information technology in this context. More precisely, we engineered a material and from its geometric quantum discord we found significant quantum correlations up to 9540 K (even without entanglement); and, a pure singlet state occupied up to around 80 K (above liquid nitrogen temperature), additionally. Our results could only be achieved due to the carboxylate group promoting a metal-to-metal huge magnetic interaction.
Data for Robust Paths to Net Greenhouse Gas Mitigation and Negative Emissions via Advanced Biofuels
This zip file contains a UNIX-format DayCent model executable, input files, automation code, and associated directory structure necessary to re-produce the DayCent analysis underlying the manuscript. The main script “autodaycent.py” (written for Python 2.7) opens an interactive command line routine that facilitates: Calibrating the DayCent pine growth model; Initializing DayCent for a set of case studies sites; Executing an ensemble of model runs representing case study site reforestation, grassland restoration, or conversion to switchgrass cultivation; and Results analysis & generation of manuscript Fig. 3. Note that the interactive analysis code requires that all input files to be contained in the directory structure as uploaded, without modification. Executable versions of the DayCent model compatible with other operating systems are available upon request.
Tritium Control and Capture in Salt-Cooled Fission and Fusion Reactors: Status, Challenges, and Path Forward
Three advanced nuclear power systems use liquid salt coolants that generate tritium and thus face the common challenges of containing and capturing tritium to prevent its release to the environment. The fluoride salt–cooled high-temperature reactor (FHR) uses clean fluoride salt coolants and the same graphite-matrix coated-particle fuel as high-temperature gas-cooled reactors. Molten salt reactors (MSRs) dissolve the fuel in a fluoride or chloride salt with release of fission product tritium into the salt. In most FHR and MSR systems, the baseline salts contain lithium where isotopically separated 7 Li is proposed to minimize tritium production from neutron interactions with the salt. The Chinese Academy of Sciences plans to start operation of a 2-MW(thermal) molten salt test reactor by 2020. For high-magnetic-field fusion machines, the use of lithium enriched in 6 Li is proposed to maximize tritium generation—the fuel for a fusion machine. Advances in superconductors that enable higher power densities may require the use of molten lithium salts for fusion blankets and as coolants. Recent technical advances in these three reactor classes have resulted in increased government and private interest and the beginning of a coordinated effort to address the tritium control challenges in 700°C liquid salt systems. In this paper, we describe characteristics of salt-cooled fission and fusion machines, the basis for growing interest in these technologies, tritium generation in molten salts, the environment for tritium capture, models for high-temperature tritium transport in salt systems, alternative strategies for tritium control, and ongoing experimental work. Several methods to control tritium appear viable. Finally, limited experimental data are the primary constraint for designing efficient cost-effective methods of tritium control.
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.
Creating Human Readable Path Constraints from Symbolic Execution.
Abstract not provided.
Accelerating Control Systems with GitOps: A Path to Automation and Reliability
GitOps is a foundational approach for modernizing infrastructure by leveraging Git as the single source of truth for declarative configurations. The poster explores how GitOps transforms traditional control system infrastructure, services and applications by enabling fully automated, auditable, and version-controlled infrastructure management. Cloud-native and containerized environments are shifting the ecosystem not only in the IT industry but also within the computational science field, as is the case of CERN and Diamond Light Source among other Accelerator/Science facilities which are slowly shifting towards modern software and infrastructure paradigms. The ACORN project, which aims to modernize Fermilab’s control system infrastructure and software is implementing proven best-practices and cutting-edge technology standards including GitOps, containerization, infrastructure as code and modern data pipelines for control system data acquisition and the inclusion of AI/ML in our accelerator complex.
Efficient Shortest Path Computations on Multi-GPU Platforms [Slides]
Abstract not provided.
Final Report for NFE-13-0019: Analysis of Muon Radiography of the Toshiba Nuclear Critical Assembly Reactor and Path Forward
A 1.2×1.2 m 2 muon tracker was moved from Los Alamos to the Toshiba facility at Kawasaki, Japan where it was used to take ~4 weeks of data radiographing the Toshiba Critical Assembly Reactor with cosmic ray muons. In this paper we describe the analysis procedure, show results of this experiment and compare the results to Monte Carlo predictions. The results validate the concept of using cosmic rays to image the damaged cores of the Fukushima Daiichi reactors.
Technical Report on NETL's Non Newtonian Multiphase Slurry Workshop: A path forward to understanding non-Newtonian multiphase slurry flows
The Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) sponsored a workshop on non-Newtonian multiphase slurry at NETL’s Morgantown campus August 19 and 20, 2013. The objective of this special two-day meeting of 20-30 invited experts from industry, National Labs and academia was to identify and address technical issues associated with handling non-Newtonian multiphase slurries across various facilities managed by DOE. Particular emphasis during this workshop was placed on applications managed by the Office of Environmental Management (EM). The workshop was preceded by two webinars wherein personnel from ORP and NETL provided background information on the Hanford WTP project and discussed the critical design challenges facing this project. In non-Newtonian fluids, viscosity is not constant and exhibits a complex dependence on applied shear stress or deformation. Many applications under EM’s tank farm mission involve non-Newtonian slurries that are multiphase in nature; tank farm storage and handling, slurry transport, and mixing all involve multiphase flow dynamics, which require an improved understanding of the mechanisms responsible for rheological changes in non-Newtonian multiphase slurries (NNMS). To discuss the issues in predicting the behavior of NNMS, the workshop focused on two topic areas: (1) State-of-the-art in non-Newtonian Multiphase Slurry Flow, and (2) Scaling up with Confidence and Ensuring Safe and Reliable Long-Term Operation.
Nuclear Security: Evaluating a System (Path Analysis)
This presentation provides a system approach that evaluates each element of the PPS and how it contributes to overall system effectiveness; provides an elemental contribution that helps define performance requirements; provides a qualitative and quantitative aspect to PPS performance; and by way of a tool, allows analysts to combine and evaluate qualitative, quantitative data.
Identification of RESNET HERS Index Values Corresponding to Minimal Complicance with the IECC Performance Path
This analysis provides a limited evaluation of the relationship between the Residential Energy Services Network (RESNET) Home Energy Rating System (HERS) Index and the simulation-based performance approach used in the 2012 International Energy Conservation Code (IECC). Not all differences between the approaches are analyzed here; only a subset of the distinctions considered likely to result in quantifiable differences in the outcomes of the two approaches or otherwise believed to be of interest to code developers and policy makers are considered. This analysis evaluates, for a single-family residence with various characteristics, the ranges of HERS Index values that would result in compliance with the 2012 IECC.
Path Scan Operational Data-Based Test Report
The TTP program is managed by DHS S&T Cyber Division and facilitates the transition of technology from the research lab to the Homeland Security Enterprise. It serves as a connection point for cyber security researchers, the Federal Government, and the private sector. Technologies targeted are those that are likely to transition successfully to the commercial market and expected to have notable impact on the cyber security of our Nation’s networks or systems. The test element of the TTP program aids in the technology transfer process and is not intended to be adversarial. Additional information on the TTP program and the iterative process used can be found in Appendix A - TTP Program Overview.
High Efficiency Structural Flowthrough Rotor with Active Flap Control: Volume Zero: Overview and Commercial Path
The Zimitar one-piece rotor primary structure is integrated, so balanced thrust and gravity loads flow through the hub region without transferring out of its composite material. Large inner rotor geometry is used since there is no need to neck down to a blade root region and pitch bearing. Rotor control is provided by a highly redundant, five flap system on each blade, sized so that easily handled standard electric linear actuators are sufficient.
GPU Acceleration of Mean Free Path Based Kernel Density Estimators in Monte Carlo Neutronics Simulations with Curvilinear Geometries
KDEs show potential reducing variance for global solutions (flux, reaction rates) when compared to histogram solutions.
Shape evolution in neutron-rich nuclei near the r-process path
To assess the resources needed to field a quantitative measurement to advance our knowledge on shape evolution, we have carried out a numerical simulation of the Coulomb excitation for 112 Ru at 460 MeV bombarding energy on a 208 Pb target of 1 mg/cm 2 using a semiclassical code, GOSIA with GRETINA/CHICO2.
The Path to Nitrate Salt Disposition
The topic is presented in a series of slides arranged according to the following outline: LANL nitrate salt incident as thermal runaway (thermally sensitive surrogates, full-scale tests), temperature control for processing, treatment options and down selection, assessment of engineering options, anticipated control set for treatment, and summary of the overall steps for RNS.