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Arctic Methane Carbon Aerosols and Tracers Study

Michelsen, Hope A.; Bambha, Ray; Lafranchi, Brian W.

The Arctic Methane, Carbon Aerosols, and Tracers Study was a measurement campaign at the NOAA Barrow Observatory and DOE ARM North Slope of Alaska sites in Barrow that involved the deployment of instruments to measure CH4, black carbon (BC), and source tracers. The campaign ran from September 1, 2014 to September 1, 2016 and was extended until July 30, 2017.

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TYPE Other Report YEAR 2018
DOIOSTI

Sierra/Aria 4.48 Verification Manual

Author, No

Presented in this document is a portion of the tests that exist in the Sierra Thermal/Fluids verification test suite. Each of these tests is run nightly with the Sierra/TF code suite and the results of the test checked under mesh refinement against the correct analytic result. For each of the tests presented in this document the test setup, derivation of the analytic solution, and comparison of the code results to the analytic solution is provided. This document can be used to confirm that a given code capability is verified or referenced as a compilation of example problems.

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TYPE SAND Report YEAR 2018
DOIOSTI

Copper Hugoniot Measurements to 2.8 TPa on Z

Furnish, Michael D.; Haill, Thomas A.

We conducted three Hugoniot and release experiments on copper on the Z machine at Hugoniot stress levels of 0.34 and 2.6 TPa, using two-layer copper/aluminum impactors traveling at 8 and 27 km/s and Z-quartz windows. Velocity histories were recorded for 4 samples of different thicknesses and 5 locations on the flyer plate (3 and 4 for the first two experiments). On-sample measurements provided Hugoniot points (via transit time) and partial release states (via Z-quartz wavespeed). Fabrication of the impactor required thick plating and several diamond-machining steps. The lower-pressure test was planned as a 2.5 TPa test, but a failure on the Z machine degraded its performance; however, these results corroborated earlier Cu data in the same stress region. The second test suffered from significant flyer plate bowing, but the third did not. The Hugoniot data are compared with the APtshuler/Nellis nuclear-driven data, other data from Z and elsewhere, and representative Sesame models.

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TYPE SAND Report YEAR 2018
DOIOSTI

Engineering Design for Wolter Imaging Diagnostic on Z

Ball, Christopher R.; Ampleford, David J.; Gard, Paul D.; Maurer, Andrew J.; Bourdon, Christopher; Fein, Jeffrey R.; Wu, Ming; Lake, Patrick; Nielsen-Weber, L.B.; Dunham, G.S.; Johnson, Drew; Johns, Owen; Sullivan, Michael A.; Kirtley, Christopher K.; Kozioziemski, B.; Pickworth, L.A.; Vogel, J.K.; Pivovaroff, M.J.; Walton, C.C.; Ayers, J.; Bell, P.; Ramsey, B.; Romaine, S.

Abstract not provided.

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TYPE Conference Poster YEAR 2018
OSTI

A Window-less Target for Magnetized Liner Inertial Fusion Characterized using High-Speed Solid-State Framing Cameras

Colombo, Anthony; Schwarz, Jens; Rambo, Patrick K.; Galloway, Benjamin R.; Kimmel, Mark; Slutz, Stephen A.; Weis, Matthew R.; Claus, Liam; England, Troy D.; Fang, Lu; Looker, Quinn M.; Mitchell, Brandon; Montoya, Andrew; Robertson, Gideon; Rochau, G.A.; Sanchez, Marcos O.; Stahoviak, John W.; Hund, Jared; Sin, Justin; Porter, John L.

Abstract not provided.

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TYPE Conference Poster YEAR 2018
OSTI

Next Generation Anodes for Lithium-ion Batteries: Thermodynamic Understanding and Abuse Performance

Fenton, Kyle R.; Allcorn, Eric; Nagasubramanian, Ganesan

As we develop new materials to increase performance of lithium ion batteries for electric vehicles, the impact of potential safety and reliability issues become increasingly important. In addition to electrochemical performance increases (capacity, energy, cycle life, etc.), there are a variety of materials advancements that can be made to improve lithium-ion battery safety. Issues including energetic thermal runaway, electrolyte decomposition and flammability, anode SEI stability, and cell-level abuse tolerance behavior. Introduction of a next generation materials, such as silicon based anode, requires a full understanding of the abuse response and degradation mechanisms for these anodes. This work aims to understand the breakdown of these materials during abuse conditions in order to develop an inherently safe power source for our next generation electric vehicles.

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TYPE Other Report YEAR 2018
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Discharge Permit-1845 Quarterly Status Report April 2018

Li, Jun

Discharge Permit (DP)-1845 was issued by the New Mexico Environment (NMED) Ground Water Quality Bureau (GWQB) for discharges via up to three injection wells in a phased Treatability Study of in-situ bioremediation of groundwater at Sandia National Laboratories, New Mexico, Technical Area-V Groundwater Area of Concern. This report fulfills the quarterly reporting requirements set forth in DP-1845, Section IV.B, Monitoring and Reporting. This reporting period is October 1st through December 31st, 2017. The report is due to NMED GWQB by May 1st, 2018.

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TYPE Other Report YEAR 2018
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Compressed sensing with sparse corruptions: Fault-tolerant sparse collocation approximations

Adcock, Ben; Bao, Anyi; Jakeman, John D.; Naryan, Akil

The recovery of approximately sparse or compressible coefficients in a polynomial chaos expansion is a common goal in many modern parametric uncertainty quantification (UQ) problems. However, relatively little effort in UQ has been directed toward theoretical and computational strategies for addressing the sparse corruptions problem, where a small number of measurements are highly corrupted. Such a situation has become pertinent today since modern computational frameworks are sufficiently complex with many interdependent components that may introduce hardware and software failures, some of which can be difficult to detect and result in a highly polluted simulation result. In this paper we present a novel compressive sampling-based theoretical analysis for a regularized t1 minimization algorithm that aims to recover sparse expansion coefficients in the presence of measurement corruptions. Our recovery results are uniform (the theoretical guarantees hold for all compressible signals and compressible corruptions vectors), and prescribe algorithmic regularization parameters in terms of a user-defined a priori estimate on the ratio of measurements that are believed to be corrupted. We also propose an iteratively reweighted optimization algorithm that automatically refines the value of the regularization parameter, and empirically produces superior results. Our numerical results test our framework on several medium-to-high dimensional examples of solutions to parameterized differential equations, and demonstrate the effectiveness of our approach.

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TYPE Other Report YEAR 2018
DOIOSTI

ECP ST Capability Assesment Report VTK-m

Moreland, Kenneth D.

The ECP/VTK-m project is providing the core capabilities to perform scientific visualization on exascale architectures. The ECP/VTK-m project fills the critical feature gap of performing visualization and analysis on processors like graphics-based processors and many integrated core. The results of this project will be delivered in tools like Para View, Vislt, and Ascent as well as in stand-alone form. Moreover, these projects are depending on this ECP effort to be able to make effective use of ECP architectures.

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TYPE Other Report YEAR 2018
DOIOSTI

Cray System Monitoring: Successes Requirements and Priorities

Ahlgren, Ville; Andersson, Stefan; Brandt, James M.; Cardo, Nicholas; Chunduri, Sudheer; Enos, Jeremy; Fields, Parks; Gentile, Ann C.; Gerber, Richard; Greenseid, Joe; Greiner, Annette; Hadri, Bilel; He, Yun; Hoppe, Dennis; Kaila, Urpo; Kelly, Kaki; Klein, Mark; Kristiansen, Alex; Leak, Steve; Mason, Mike; Pedretti, Kevin; Piccinali, Jean-Guillaume; Repik, Jason J.; Rogers, Jim; Salminen, Susanna; Showerman, Mike; Whitney, Cary; Williams, Jim

Abstract not provided.

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TYPE Conference Poster YEAR 2018
OSTI

Recent research on stishovite: Hugoniot and partial release Z experiments and DFT EOS calculations

Furnish, Michael D.; Shulenburger, Luke; Desjarlais, Michael; Fei, Yingwei

We have conducted a series of ride-along experiments on the Z facility to ascertain the Hugoniot of silica centered in the stishovite phase over a range 0.4 - 1.0 TPa, together with partial release states produced at the interface between the sample and a fused silica window. The stishovite samples were synthesized in a large-volume multi-anvil press at 15 GPa and 1773 K, with an initial density of 4.29 gm/cc. The new Z experiments on stishovite fill in a gap between gas gun experiments and NIF experiments. The states are compared with the Hugoniots of quartz and fused silica for inferences as to EOS. They are generally consistent with Sesame 7360 predictions. Sound speed constraints from these data are discussed. The new Hugoniot data cross over the melting curve of stishovite; together with the partial-release data and predictions from density-functional theory modeling, they provide insights into the properties of solid and liquid under extreme conditions. These data are fundamentally important for understanding the interior of silicate-based super-Earths.

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TYPE SAND Report YEAR 2018
DOIOSTI

A Minimum Variance Algorithm for Overdetermined TOA Equations with an Altitude Constraint

Romero, Louis A.; Mason, John J.

We present a direct (non-iterative) method for solving for the location of a radio frequency (RF) emitter, or an RF navigation receiver, using four or more time of arrival (TOA) measurements and an assumed altitude above an ellipsoidal earth. Both the emitter tracking problem and the navigation application are governed by the same equations, but with slightly different interpreta- tions of several variables. We treat the assumed altitude as a soft constraint, with a specified noise level, just as the TOA measurements are handled, with their respective noise levels. With 4 or more TOA measurements and the assumed altitude, the problem is overdetermined and is solved in the weighted least squares sense for the 4 unknowns, the 3-dimensional position and time. We call the new technique the TAQMV (TOA Altitude Quartic Minimum Variance) algorithm, and it achieves the minimum possible error variance for given levels of TOA and altitude estimate noise. The method algebraically produces four solutions, the least-squares solution, and potentially three other low residual solutions, if they exist. In the lightly overdermined cases where multiple local minima in the residual error surface are more likely to occur, this algebraic approach can produce all of the minima even when an iterative approach fails to converge. Algorithm performance in terms of solution error variance and divergence rate for bas eline (iterative) and proposed approach are given in tables.

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TYPE SAND Report YEAR 2018
DOIOSTI
Results 30401–30600 of 99,299
Results 30401–30600 of 99,299
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