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open access

Afghanistan: Background and U.S. Policy in Brief

Description: This report provides an overview of current political and military dynamics, with a focus on the Trump Administration's new strategy for Afghanistan and South Asia, the U.S.-led coalition and Afghan military operations, and recent political developments, including prospects for peace talks and elections.
Date: March 5, 2018
Creator: Thomas, Clayton
Item Type: Refine your search to only Report
open access

Iraq: In Brief

Description: This report discusses Iraq's political and governmental structure, economy, humanitarian issues, military operations, and relations with the U.S.
Date: March 5, 2018
Creator: Blanchard, Christopher M.
Item Type: Refine your search to only Report
open access

Joint-Resolution Seeks to End U.S. Support for Saudi-led Coalition Military Operations in Yemen

Description: This report discusses Senate Joint Resolution 54 which directs the President to remove U.S. forces from "hostilities in or affecting" Yemen (except for those U.S. forces engaged in counterterrorism operations directed at al Qaeda or associated forces). It provides a brief overview of U.S. involvement in Yemen both militarily and diplomatically through advisement of Saudi Arabia on reducing civilian casulaties and refueling of Saudi planes used in airstrikes.
Date: March 5, 2018
Creator: Blanchard, Christopher M.; Sharp, Jeremy M. & Weed, Matthew C.
Item Type: Refine your search to only Report
open access

Thermal Degradation Studies of Polyurethane/POSS Nanohybrid Elastomers

Description: Reported here is the synthesis of a series of Polyurethane/POSS nanohybrid elastomers, the characterization of their thermal stability and degradation behavior at elevated temperatures using a combination of Thermal Gravimetric Analysis (TGA) and Thermal Volatilization Analysis (TVA). A series of PU elastomers systems have been formulated incorporating varying levels of 1,2-propanediol-heptaisobutyl-POSS (PHIPOSS) as a chain extender unit, replacing butane diol. The bulk thermal stability of th… more
Date: March 5, 2010
Creator: Lewicki, J P; Pielichowski, K; TremblotDeLaCroix, P; Janowski, B; Todd, D & Liggat, J J
Item Type: Refine your search to only Article
open access

Pressure-induced isostructural transition in PdN2

Description: We show that a synthesized Pd-N compound crystallize into the pyrite structure by comparison of experimental and calculated Raman intensities. The decreasing Raman intensities with decreasing pressure is explained by a closing of the fundamental band gap. We further discuss the experimental decomposition of this compound at 11 GPa in terms of an isostructural transition within the pyrite structure.
Date: March 5, 2010
Creator: Aberg, D; Erhart, P; Crowhurst, J; Zaug, J M; Goncharov, A F & Sadigh, B
Item Type: Refine your search to only Article
open access

Towards the understanding of PETN initiation by a fast, high power arc source

Description: We present a thorough characterization of a capacitor driven arc source that can deliver up to 200 mJ of energy to the arc and high explosive in a well-controlled, repeatable manner on the hundreds of nanoseconds time-scale. Our ultimate purpose is to create a platform to study high explosive kinetics under extreme conditions of high-temperature. In the current paper, we characterize the behavior of our arc source by electrical discharge over a thin PETN film. Temperature and density are determ… more
Date: March 5, 2010
Creator: Grant, C D; Tang, V; Glascoe, E A & McCarrick, J F
Item Type: Refine your search to only Article
open access

Comparison of the Growth of Pore and Shear Band Driven Detonations

Description: The authors examine the effect of ignition site topology on the rate of reaction of a detonating material. The hot plane, hot line, and hot finite patch topologies are added to previous work on hot spot ignition. The hot plane and hot patch ignition forms would arise from ignition due to shear banding, and the hot line ignition form is shown to complete the topological set. The limiting behavior of instantaneous ignition is considered and used to construct simple reaction rate vs. extent of rea… more
Date: March 5, 2010
Creator: Nichols, A. L.
Item Type: Refine your search to only Article
open access

Improved Modeling and Understanding of Diffusion-Media Wettability on Polymer-Electrolyte-Fuel-Cell Performance

Description: A macroscopic-modeling methodology to account for the chemical and structural properties of fuel-cell diffusion media is developed. A previous model is updated to include for the first time the use of experimentally measured capillary pressure -- saturation relationships through the introduction of a Gaussian contact-angle distribution into the property equations. The updated model is used to simulate various limiting-case scenarios of water and gas transport in fuel-cell diffusion media. An… more
Date: March 5, 2010
Creator: Weber, Adam
Item Type: Refine your search to only Article
open access

Fracture Induced Sub-Band Absorption as a Precursor to Optical Damage on Fused Silica Surfaces

Description: The optical damage threshold of indentation induced flaws on fused silica surfaces was explored. Mechanical flaws were characterized by laser damaged testing, SEM, optical, and photoluminescence microscopy. Localized polishing, chemical etching, and the control of indentation morphology were used to isolate the structural features which limit optical damage. A thin defect layer on fracture surfaces, including those smaller than the wavelength of visible light, was found to be the dominant sourc… more
Date: March 5, 2010
Creator: Miller, P E; Bude, J D; Suratwala, T I; Shen, N; Laurence, T A; Steele, W A et al.
Item Type: Refine your search to only Article
open access

Mechanisms underlying cellular responses of cells from haemopoietic tissue to low dose/low LET radiation

Description: To accurately define the risks associated with human exposure to relevant environmental doses of low LET ionizing radiation, it is necessary to completely understand the biological effects at very low doses (i.e., less than 0.1 Gy), including the lowest possible dose, that of a single electron track traversal. At such low doses, a range of studies have shown responses in biological systems which are not related to the direct interaction of radiation tracks with DNA. The role of these “non-targe… more
Date: March 5, 2010
Creator: Kadhim, Munira A
Item Type: Refine your search to only Report
open access

High-Power Electrostatic Discharges in PETN: Threshold and Scaling Experiments

Description: There is a considerable set of data establishing the safety of PETN-based detonators that are insulted by electrostatic discharge (ESD) from a human body. However, the subject of ESD safety has garnered renewed interest because of the sparse data on high-power, low-impedance discharges that result when the source is a metallic object such as a tool. Experiments on as-built components, using pin-to-cap fault circuits through PETN-based detonators, showed significant evidence of a power dependenc… more
Date: March 5, 2010
Creator: Liou, W.; McCarrick, J. F.; Hodgin, R. L. & Phillips, D. F.
Item Type: Refine your search to only Article
open access

Propagation of Reactions in Thermally-damaged PBX-9501

Description: A thermally-initiated explosion in PBX-9501 (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) is observed in situ by flash x-ray imaging, and modeled with the LLNL multi-physics arbitrary-Lagrangian-Eulerian code ALE3D. The containment vessel deformation provides a useful estimate of the reaction pressure at the time of the explosion, which we calculate to be in the range 0.8-1.4 GPa. Closely-coupled ALE3D simulations of these experiments, utilizing the multi-phase convective burn model, provi… more
Date: March 5, 2010
Creator: Tringe, J W; Glascoe, E A; Kercher, J R; Willey, T M; Springer, H K; Greenwood, D W et al.
Item Type: Refine your search to only Article
open access

Annual Report: Carbon Capture Simulation Initiative (CCSI) (30 September 2013)

Description: The Carbon Capture Simulation Initiative (CCSI) is a partnership among national laboratories, industry and academic institutions that is developing and deploying state-of-the-art computational modeling and simulation tools to accelerate the commercialization of carbon capture technologies from discovery to development, demonstration, and ultimately the widespread deployment to hundreds of power plants. The CCSI Toolset will provide end users in industry with a comprehensive, integrated suite of… more
Date: March 5, 2014
Creator: Miller, David C.; Syamlal, Madhava; Cottrell, Roger; Kress, Joel D.; Sundaresan, S.; Sun, Xin et al.
Item Type: Refine your search to only Report
open access

Visualization and Analysis-Oriented Reconstruction of Material Interfaces

Description: Reconstructing boundaries along material interfaces from volume fractions is a difficult problem, especially because the under-resolved nature of the input data allows for many correct interpretations. Worse, algorithms widely accepted as appropriate for simulation are inappropriate for visualization. In this paper, we describe a new algorithm that is specifically intended for reconstructing material interfaces for visualization and analysis requirements. The algorithm performs well with respec… more
Date: March 5, 2010
Creator: Childs, Henry R.
Item Type: Refine your search to only Article
open access

Multi-Scale Mass Transfer Processes Controlling Natural Attenuation and Engineered Remediation: An IFRC Focused on Hanford’s 300 Area Uranium Plume January 2011 to January 2012

Description: The Integrated Field Research Challenge (IFRC) at the Hanford Site 300 Area uranium (U) plume addresses multi-scale mass transfer processes in a complex subsurface biogeochemical setting where groundwater and riverwater interact. A series of forefront science questions on reactive mass transfer motivates research. These questions relate to the effect of spatial heterogeneities; the importance of scale; coupled interactions between biogeochemical, hydrologic, and mass transfer processes; and mea… more
Date: March 5, 2012
Creator: Zachara, John M.; Bjornstad, Bruce N.; Christensen, John N.; Conrad, Mark S.; Fredrickson, Jim K.; Freshley, Mark D. et al.
Item Type: Refine your search to only Report
open access

Documented Safety Analysis for the Waste Storage Facilities March 2010

Description: This Documented Safety Analysis (DSA) for the Waste Storage Facilities was developed in accordance with 10 CFR 830, Subpart B, 'Safety Basis Requirements,' and utilizes the methodology outlined in DOE-STD-3009-94, Change Notice 3. The Waste Storage Facilities consist of Area 625 (A625) and the Decontamination and Waste Treatment Facility (DWTF) Storage Area portion of the DWTF complex. These two areas are combined into a single DSA, as their functions as storage for radioactive and hazardous wa… more
Date: March 5, 2010
Creator: Laycak, D T
Item Type: Refine your search to only Report
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