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Jump to search filtersRed Storm: The Birth of a New Supercomputer
Abstract not provided.
VISIBLE EMISSION OF HYDROGEN FLAMES
Combustion and Flame Journal
Abstract not provided.
History Advancements and New Developments in Techniques to Characterize Impact Phenomena
Abstract not provided.
Radiative Properties of Implosions of Stainless Steel Wire Arrays with Application to Astrophysics
Proceedings of the 7th International Conference on Dense Z pinches
Abstract not provided.
ER Groundwater Units Fact Sheet
Abstract not provided.
Performance Assessment for the Proposed Yucca Mountain Repository
Abstract not provided.
An "All Things Nuclear" Approach to Reducing Global Nuclear Danger
Abstract not provided.
Experimental Comparison of Particle Interaction Measurement Techniques Using Optical Trapping
Abstract not provided.
Single Ion Detection Approaches
Abstract not provided.
A new look at the specification of ITER plasma wall interactionsand tritium retention
Abstract not provided.
Excellence in Engineering: The Role of Education and Knowledge Management
Abstract not provided.
Surface Flashover of Oil-Immersed Dielectric Materials in Uniform and Non-Uniform Fields
IEEE Transactions on Dielectrics and Electrical Insulation
Abstract not provided.
System Integration Test Procedure (SITP) FD-332 and FD-432 Fiber Defender Sensor
Abstract not provided.
DOE/Sandia Responses to NMED "Notice of Disapproval: Summary Report Technical Area V Monitoring Well Plug and Abandonment - Decommissioning of Groundwater Monitoring (GWM) Well TAV-MW1 Installation of GWM Well TAV-MW10 SNL August 6 2008
Abstract not provided.
DOE/Sandia Responses to NMED "Notice of Disapproval: Summary Report Mixed Waste Landfill Monitoring Well Plug and Abandonment - Decommissioning of Groundwater Monitoring (GWM) Well MWL-BW1 Installation of GWM Well MWL-BW2 SNL " August 25 2008
Abstract not provided.
Climate-derived tensions in Arctic security
Globally, there is no lack of security threats. Many of them demand priority engagement and there can never be adequate resources to address all threats. In this context, climate is just another aspect of global security and the Arctic just another region. In light of physical and budgetary constraints, new security needs must be integrated and prioritized with existing ones. This discussion approaches the security impacts of climate from that perspective, starting with the broad security picture and establishing how climate may affect it. This method provides a different view from one that starts with climate and projects it, in isolation, as the source of a hypothetical security burden. That said, the Arctic does appear to present high-priority security challenges. Uncertainty in the timing of an ice-free Arctic affects how quickly it will become a security priority. Uncertainty in the emergent extreme and variable weather conditions will determine the difficulty (cost) of maintaining adequate security (order) in the area. The resolution of sovereignty boundaries affects the ability to enforce security measures, and the U.S. will most probably need a military presence to back-up negotiated sovereignty agreements. Without additional global warming, technology already allows the Arctic to become a strategic link in the global supply chain, possibly with northern Russia as its main hub. Additionally, the multinational corporations reaping the economic bounty may affect security tensions more than nation-states themselves. Countries will depend ever more heavily on the global supply chains. China has particular needs to protect its trade flows. In matters of security, nation-state and multinational-corporate interests will become heavily intertwined.
CAMU Fact Sheet
Abstract not provided.
Sandia Fire Programs
Abstract not provided.
ASC FY08 program Plan
Abstract not provided.
Interface physics in microporous media : LDRD final report
This document contains a summary of the work performed under the LDRD project entitled 'Interface Physics in Microporous Media'. The presence of fluid-fluid interfaces, which can carry non-zero stresses, distinguishes multiphase flows from more readily understood single-phase flows. In this work the physics active at these interfaces has been examined via a combined experimental and computational approach. One of the major difficulties of examining true microporous systems of the type found in filters, membranes, geologic media, etc. is the geometric uncertainty. To help facilitate the examination of transport at the pore-scale without this complication, a significant effort has been made in the area of fabrication of both two-dimensional and three-dimensional micromodels. Using these micromodels, multiphase flow experiments have been performed for liquid-liquid and liquid-gas systems. Laser scanning confocal microscopy has been utilized to provide high resolution, three-dimensional reconstructions as well as time resolved, two-dimensional reconstructions. Computational work has focused on extending lattice Boltzmann (LB) and finite element methods for probing the interface physics at the pore scale. A new LB technique has been developed that provides over 100x speed up for steady flows in complex geometries. A new LB model has been developed that allows for arbitrary density ratios, which has been a significant obstacle in applying LB to air-water flows. A new reduced order model has been developed and implemented in finite element code for examining non-equilibrium wetting in microchannel systems. These advances will enhance Sandia's ability to quantitatively probe the rich interfacial physics present in microporous systems.
Hyperspectral imaging of oil producing microalgae under thermal and nutritional stress
This short-term, late-start LDRD examined the effects of nutritional deprivation on the energy harvesting complex in microalgae. While the original experimental plan involved a much more detailed study of temperature and nutrition on the antenna system of a variety of TAG producing algae and their concomitant effects on oil production, time and fiscal constraints limited the scope of the study. This work was a joint effort between research teams at Sandia National Laboratories, New Mexico and California. Preliminary results indicate there is a photosystem response to silica starvation in diatoms that could impact the mechanisms for lipid accumulation.
RAPID PORTABLE DIAGNOSTIC PLATFORM FOR TOXIN/PATHOGEN EXPOSURE SCENARIOS
Abstract not provided.
HOCWOG Presentation for JOWOG31
Abstract not provided.
Analysis HOCWOC Update for JOWOG31
Abstract not provided.
Investment Planning and Analysis for CBRN
Abstract not provided.
Implementation of a Pseudo-Bending Seismic Travel Time Calculator in a Distributed Parallel Computing Environment
Abstract not provided.
RPSS to JOWOG
Abstract not provided.
ASEDRA Evaluation Final Report
The performance of the Advanced Synthetically Enhanced Detector Resolution Algorithm (ASEDRA) was evaluated by performing a blind test of 29 sets of gamma-ray spectra that were provided by DNDO. ASEDRA is a post-processing algorithm developed at the Florida Institute of Nuclear Detection and Security at the University of Florida (UF/FINDS) that extracts char-acteristic peaks in gamma-ray spectra. The QuickID algorithm, also developed at UF/FINDS, was then used to identify nuclides based on the characteristic peaks generated by ASEDRA that are inferred from the spectra. The ASEDRA/QuickID analysis results were evaluated with respect to the performance of the DHSIsotopeID algorithm, which is a mature analysis tool that is part of the Gamma Detector Response and Analysis Software (GADRAS). Data that were used for the blind test were intended to be challenging, and the radiation sources included thick shields around the radioactive materials as well as cargo containing naturally occurring radio-active materials, which masked emission from special nuclear materials and industrial isotopes. Evaluation of the analysis results with respect to the ground truth information (which was provided after the analyses were finalized) showed that neither ASEDRA/QuickID nor GADRAS could identify all of the radiation sources correctly. Overall, the purpose of this effort was primarily to evaluate ASEDRA, and GADRAS was used as a standard against which ASEDRA was compared. Although GADRAS was somewhat more accurate on average, the performance of ASEDRA exceeded that of GADRAS for some of the unknowns. The fact that GADRAS also failed to identify many of the radiation sources attests to the difficulty of analyzing the blind-test data that were used as a basis for the evaluation. This evaluation identified strengths and weaknesses of the two analysis approaches. The importance of good calibration data was also clear because the performance of both analysis methods was impeded by the inability to define the energy calibration accurately. Acronyms ACHIP adaptive chi-processed ASEDRA Advanced Synthetically Enhanced Detector Resolution Algorithm DNDO Domestic Nuclear Detection Office DRFs Detector Response Functions FINDS Florida Institute of Nuclear Detection and Security FWHM full-width half-maximum GADRAS Gamma Detector Response Analysis Software GUI graphical user interface HEU highly enriched uranium HPGe high purity germanium ID identification NaI Sodium iodide NNSA National Nuclear Security Administration NORM Naturally Occurring Radioactive Materials ppm parts per million SNL Sandia National Laboratories UF University of Florida WGPu weapons-grade plutonium
Multiphase and Reactive Flow Modeling
Abstract not provided.
Tritium Storage Material
Nano-structured palladium is examined as a tritium storage material with the potential to release beta-decay-generated helium at the generation rate, thereby mitigating the aging effects produced by enlarging He bubbles. Helium retention in proposed structures is modeled by adapting the Sandia Bubble Evolution model to nano-dimensional material. The model shows that even with ligament dimensions of 6-12 nm, elevated temperatures will be required for low He retention. Two nanomaterial synthesis pathways were explored: de-alloying and surfactant templating. For de-alloying, PdAg alloys with piranha etchants appeared likely to generate the desired morphology with some additional development effort. Nano-structured 50 nm Pd particles with 2-3 nm pores were successfully produced by surfactant templating using PdCl salts and an oligo(ethylene oxide) hexadecyl ether surfactant. Tests were performed on this material to investigate processes for removing residual pore fluids and to examine the thermal stability of pores. A tritium manifold was fabricated to measure the early He release behavior of this and Pd black material and is installed in the Tritium Science Station glove box at LLNL. Pressure-composition isotherms and particle sizes of a commercial Pd black were measured.
Quality Control
Abstract not provided.
Us Test Facility Conditions Towards An Expedited Testing for FW Qualification Under MARFE
Abstract not provided.
Effect of Electron Beam size on High Heat Flux Testing of Be First Wall Tiles
Abstract not provided.
Evaluating Security Measures with Modeling and Simulation
Abstract not provided.
YUCCA MOUNTAIN 2008 PERFORMANCE ASSESSMENT: MODELING THE ENGINEERED BARRIER SYSTEM
Abstract not provided.
Sandia National Laboratories "Overview" for John Fleck
Abstract not provided.
Quantification of uncertainty in machining operations for on-machine acceptance
Manufactured parts are designed with acceptance tolerances, i.e. deviations from ideal design conditions, due to unavoidable errors in the manufacturing process. It is necessary to measure and evaluate the manufactured part, compared to the nominal design, to determine whether the part meets design specifications. The scope of this research project is dimensional acceptance of machined parts; specifically, parts machined using numerically controlled (NC, or also CNC for Computer Numerically Controlled) machines. In the design/build/accept cycle, the designer will specify both a nominal value, and an acceptable tolerance. As part of the typical design/build/accept business practice, it is required to verify that the part did meet acceptable values prior to acceptance. Manufacturing cost must include not only raw materials and added labor, but also the cost of ensuring conformance to specifications. Ensuring conformance is a substantial portion of the cost of manufacturing. In this project, the costs of measurements were approximately 50% of the cost of the machined part. In production, cost of measurement would be smaller, but still a substantial proportion of manufacturing cost. The results of this research project will point to a science-based approach to reducing the cost of ensuring conformance to specifications. The approach that we take is to determine, a priori, how well a CNC machine can manufacture a particular geometry from stock. Based on the knowledge of the manufacturing process, we are then able to decide features which need further measurements from features which can be accepted 'as is' from the CNC. By calibration of the machine tool, and establishing a machining accuracy ratio, we can validate the ability of CNC to fabricate to a particular level of tolerance. This will eliminate the costs of checking for conformance for relatively large tolerances.
September 2008 Construction News Sense
Abstract not provided.
Variable affecting measurement of sustained load cracking thresholds in hydrogen gas
Abstract not provided.
Impact of ALEGRA on Army Research Laboratory Experimental Program
Abstract not provided.
Managing Age-related Changes in Device Radiation-Response
Year in Review of Operational Challenges TRTR Conference Sept 28-Oct 2 2008
Abstract not provided.
Weapon Internship Prgoram
Abstract not provided.
Oxygen Incorporation in Erbium Dihydride Thin Films
Abstract not provided.
Automated SNM Analysis for Gamma-Ray Spectra
Abstract not provided.
Final report on LDRD project : advanced optical trigger systems
Advanced optically-activated solid-state electrical switch development at Sandia has demonstrated multi-kA/kV switching and the path for scalability to even higher current/power. Realization of this potential requires development of new optical sources/switches based on key Sandia photonic device technologies: vertical-cavity surface-emitting lasers (VCSELs) and photoconductive semiconductor switch (PCSS) devices. The key to increasing the switching capacity of PCSS devices to 5kV/5kA and higher is to distribute the current in multiple parallel line filaments triggered by an array of high-brightness line-shaped illuminators. Commercial mechanically-stacked edge-emitting lasers have been used to trigger multiple filaments, but they are difficult to scale and manufacture with the required uniformity. In VCSEL arrays, adjacent lasers utilize identical semiconductor material and are lithographically patterned to the required dimensions. We have demonstrated multiple-line filament triggering using VCSEL arrays to approximate line generation. These arrays of uncoupled circular-aperture VCSELs have fill factors ranging from 2% to 30%. Using these arrays, we have developed a better understanding of the illumination requirements for stable triggering of multiple-filament PCSS devices. Photoconductive semiconductor switch (PCSS) devices offer advantages of high voltage operation (multi-kV), optical isolation, triggering with laser pulses that cannot occur accidentally in nature, low cost, high speed, small size, and radiation hardness. PCSS devices are candidates for an assortment of potential applications that require multi-kA switching of current. The key to increasing the switching capacity of PCSS devices to 5kV/5kA and higher is to distribute the current in multiple parallel line filaments triggered by an array of high-brightness line-shaped illuminators. Commercial mechanically-stacked edge-emitting lasers have been demonstrated to trigger multiple filaments, but they are difficult to scale and manufacture with the required uniformity. As a promising alternative to multiple discrete edge-emitting lasers, a single wafer of vertical-cavity surface-emitting lasers (VCSELs) can be lithographically patterned to achieve the desired layout of parallel line-shaped emitters, in which adjacent lasers utilize identical semiconductor material and thereby achieve a degree of intrinsic optical uniformity. Under this LDRD project, we have fabricated arrays of uncoupled circular-aperture VCSELs to approximate a line-shaped illumination pattern, achieving optical fill factors ranging from 2% to 30%. We have applied these VCSEL arrays to demonstrate single and dual parallel line-filament triggering of PCSS devices. Moreover, we have developed a better understanding of the illumination requirements for stable triggering of multiple-filament PCSS devices using VCSEL arrays. We have found that reliable triggering of multiple filaments requires matching of the turn-on time of adjacent VCSEL line-shaped-arrays to within approximately 1 ns. Additionally, we discovered that reliable triggering of PCSS devices at low voltages requires more optical power than we obtained with our first generation of VCSEL arrays. A second generation of higher-power VCSEL arrays was designed and fabricated at the end of this LDRD project, and testing with PCSS devices is currently underway (as of September 2008).
Multigrid & Optimal Solvers
Abstract not provided.
R&D for computational cognitive and social models : foundations for model evaluation through verification and validation (final LDRD report)
High-throughput proteomics : optical approaches
Realistic cell models could greatly accelerate our ability to engineer biochemical pathways and the production of valuable organic products, which would be of great use in the development of biofuels, pharmaceuticals, and the crops for the next green revolution. However, this level of engineering will require a great deal more knowledge about the mechanisms of life than is currently available. In particular, we need to understand the interactome (which proteins interact) as it is situated in the three dimensional geometry of the cell (i.e., a situated interactome), and the regulation/dynamics of these interactions. Methods for optical proteomics have become available that allow the monitoring and even disruption/control of interacting proteins in living cells. Here, a range of these methods is reviewed with respect to their role in elucidating the interactome and the relevant spatial localizations. Development of these technologies and their integration into the core competencies of research organizations can position whole institutions and teams of researchers to lead in both the fundamental science and the engineering applications of cellular biology. That leadership could be particularly important with respect to problems of national urgency centered around security, biofuels, and healthcare.
Capabilities for Uncertainty in Predictive Science (LDRD Final Report)
Predictive simulation of systems comprised of numerous interconnected, tightly coupled components promises to help solve many problems of scientific and national interest. However predictive simulation of such systems is extremely challenging due to the coupling of a diverse set of physical and biological length and time scales. This report investigates un-certainty quantification methods for such systems that attempt to exploit their structure to gain computational efficiency. The traditional layering of uncertainty quantification around nonlinear solution processes is inverted to allow for heterogeneous uncertainty quantification methods to be applied to each component in a coupled system. Moreover this approach allows stochastic dimension reduction techniques to be applied at each coupling interface. The mathematical feasibility of these ideas is investigated in this report, and mathematical formulations for the resulting stochastically coupled nonlinear systems are developed.
Trouble at the source : water, the environment and international security
Abstract not provided.
Metal Fire Implications for Advanced Reactors, Part 2: PIRT Results
This report documents the results of a Phenomena Identification and Ranking Table (PIRT) exercise performed at Sandia National Laboratories (SNL) as well as the experimental and modeling program that have been designed based on the PIRT results. A PIRT exercise is a structured and facilitated expert elicitation process. In this case, the expert panel was comprised of nine recognized fire science and aerosol experts. The objective of a PIRT exercise is to identify phenomena associated with the intended application and to then rank the current state of knowledge relative to each identified phenomenon. In this particular PIRT exercise the intended application was sodium fire modeling related to sodium-cooled advanced reactors. The panel was presented with two specific fire scenarios, each based on a hypothetical sodium leak in an Advanced Breeder Test Reactor (ABTR) design. For both scenarios the figure of merit was the ability to predict the thermal and aerosol insult to nearby equipment (i.e. heat exchangers and other electrical equipment). When identifying phenomena of interest, and in particular when ranking phenomena importance and the adequacy of existing modeling tools and data, the panel was asked to subjectively weigh these factors in the context of the specified figure of merit. Given each scenario, the panel identified all those related phenomena that are of potential interest to an assessment of the scenario using fire modeling tools to evaluate the figure of merit. Each phenomenon is then ranked relative to its importance in predicting the figure of merit. Each phenomenon is then further ranked for the existing state of knowledge with respect to the ability of existing modeling tools to predict that phenomena, the underlying base of data associated with the phenomena, and the potential for developing new data to support improvements to the existing modeling tools. For this PIRT two hypothetical sodium leak scenarios were evaluated for the ABTR design. The first scenario was a leak in the hot side of the intermediate heat transport system (IHTS) resulting in a sodium pool fire. The second scenario was a leak in the cold side of the IHTS resulting in a sodium spray fire.
Concentration and force field dependence of the structure of aqueous solutions of monosodium glutamate
Proposed for publication in the Journal of Physical Chemistry B.
Abstract not provided.
Viral RNA testing and automation on the bead-based CBNE detection microsystem
Borazine Precursors for Boron Nitride Anti Friction Coatings for MEMS
2,4,6-Triazidoborazine is an explosive material that contains no carbon or oxygen. There is very little discussion of this material in the open literature, and due to the nature of this class of compounds, it is possible that a sophisticated adversary could produce and deploy this material. This work was undertaken to understand this material’s chemical and explosive properties. This paper documents the experimental procedure and results of this LORD.
Large-area subwavelength aperture arrays fabricated using nanoimprint lithography
IEEE Transactions on Nanotechnology
We report on the fabrication and characterization of large-area 2-D square arrays of subwavelength holes in Ag and Al films. Fabrication is based on thermal nanoimprint lithography and metal evaporation, without the need for etching, and is compatible with low-cost, large-scale production. Reflectance spectra for these arrays display an intensity minimum whose amplitude, center wavelength, and line width depend on the geometry of the array and the reflectivity of the metal film. By placing various fluids in contact with the subwavelength aperture arrays, we observe that the center wavelength of the reflectance minimum varies linearly with the refractive index of the fluid with a sensitivity of over 500 nm per refractive index unit. The surface plasmon theory is used to predict sensitivities to refractive index change with accuracies better than 0.5%. © 2008 IEEE.
Preface to engineering with computers special edition on trends in unstructured mesh generation
Engineering with Computers
Abstract not provided.
Thermal conductivity measurements on polysilicon microbridges using the 3-omega technique
2008 Proceedings of the ASME Micro/Nanoscale Heat Transfer International Conference, MNHT 2008
The thermal properties of microelectromechanical systems (MEMS) devices are governed by the structure and composition of the constituent materials as well as the geometrical design. With the continued reduction of the characteristic sizes of these devices, experimental determination of the thermal properties becomes more difficult. In this study, the thermal conductivity of polycrystalline silicon (polysilicon) microbridges are measured with the transient 3ω technique and compared to measurements on the same structures using a steady state joule heating technique. The microbridges with lengths from 200 microns to 500 microns were designed and fabricated using the Sandia National Laboratories SUMMiT™ V surface micromachining process. The differences between the two measurements, which arise from the geometry of the test structures, are explained by bond pad heating and thermal boundary resistance effects. Copyright © 2008 by ASME.
Thermal conductivity measurements on polysilicon microbridges using the 3-omega technique
2008 Proceedings of the ASME Micro/Nanoscale Heat Transfer International Conference, MNHT 2008
The thermal properties of microelectromechanical systems (MEMS) devices are governed by the structure and composition of the constituent materials as well as the geometrical design. With the continued reduction of the characteristic sizes of these devices, experimental determination of the thermal properties becomes more difficult. In this study, the thermal conductivity of polycrystalline silicon (polysilicon) microbridges are measured with the transient 3ω technique and compared to measurements on the same structures using a steady state joule heating technique. The microbridges with lengths from 200 microns to 500 microns were designed and fabricated using the Sandia National Laboratories SUMMiT™ V surface micromachining process. The differences between the two measurements, which arise from the geometry of the test structures, are explained by bond pad heating and thermal boundary resistance effects. Copyright © 2008 by ASME.
Lattice match in density functional calculations: Ice Ih vs. β-AgI
Physical Chemistry Chemical Physics
Density functional optimizations of the crystal parameters of ice Ih and β-AgI imply lattice mismatches of 4.2 to 7.9%, in a survey of eight common, approximate (non-hybrid) functionals, too large to allow a meaningful contribution from Density Functional Theory to the discussion of the significance of lattice match in ice nucleation. © the Owner Societies.
Using duplication with compare for on-line error detection in FPGA-based designs
IEEE Aerospace Conference Proceedings
It is well known that SRAM-based FPGAs are susceptible to single-event upsets (SEUs) in radiation environments. A variety of mitigation strategies have been demonstrated to provide appropriate mitigation and correction of SEUs in these environments. While full mitigation of SEUs is appropriate for some situations, some systems may tolerate SEUs as long as these upsets are detected quickly and correctly. These systems require effective error detection techniques rather than costly error correction methods. This work leverages a well-known error detection technique for FPGAs called duplication with compare (DWC). This technique has been shown to be very effective at quickly and accurately detecting SEUs using fault injection and radiation testing. ©2008 IEEE.
Analysis and computation of a least-squares method for consistent mesh tying
Journal of Computational and Applied Mathematics
In the finite element method, a standard approach to mesh tying is to apply Lagrange multipliers. If the interface is curved, however, discretization generally leads to adjoining surfaces that do not coincide spatially. Straightforward Lagrange multiplier methods lead to discrete formulations failing a first-order patch test [T.A. Laursen, M.W. Heinstein, Consistent mesh-tying methods for topologically distinct discretized surfaces in non-linear solid mechanics, Internat. J. Numer. Methods Eng. 57 (2003) 1197-1242]. This paper presents a theoretical and computational study of a least-squares method for mesh tying [P. Bochev, D.M. Day, A least-squares method for consistent mesh tying, Internat. J. Numer. Anal. Modeling 4 (2007) 342-352], applied to the partial differential equation - ∇2 φ + α φ = f. We prove optimal convergence rates for domains represented as overlapping subdomains and show that the least-squares method passes a patch test of the order of the finite element space by construction. To apply the method to subdomain configurations with gaps and overlaps we use interface perturbations to eliminate the gaps. Theoretical error estimates are illustrated by numerical experiments. © 2007 Elsevier B.V. All rights reserved.
Asymmetric cubature formulas for polynomial integration in the triangle and square
Journal of Computational and Applied Mathematics
We present five new cubature formula in the triangle and square for exact integration of polynomials. The points were computed numerically with a cardinal function algorithm which does not impose any symmetry requirements on the points. Cubature formula are presented which integrate degrees 10, 11 and 12 in the triangle and degrees 10 and 12 in the square. They have positive weights, contain no points outside the domain, and have fewer points than previously known results. © 2007 Elsevier B.V. All rights reserved.
The role of collisions in the aligned growth of vertical nanowires
Journal of Crystal Growth
We report a route to highly aligned, vertical arrays of GaN nanowires in which the degree of vertical alignment is improved via collisions between nanowires during growth. An investigation of the initial growth process indicates that in addition to vertically aligned nanowires a significant fraction of tilted nanowires also nucleate, the density of which appears to sharply decrease with growth time. We attribute this decay in the density of tilted nanowires during growth to collisions with vertical nanowires, which terminate the growth of tilted nanowires shortly after nucleation. The experimentally observed tilted nanowire density evolution agrees well with a Monte Carlo model developed to simulate the collision process. The results show that at high nanowire densities this collision mechanism rapidly terminates the growth of tilted nanowires, leading to highly aligned, vertical nanowire arrays. © 2008 Elsevier B.V.
Electrical discharge across micrometer-scale gaps for planar MEMS structures in air at atmospheric pressure
Journal of Micromechanics and Microengineering
We examine electrical discharge current responses across atmospheric pressure air gaps in the 2 νm to 7 νm range between planar polysilicon microstructures to determine the physical process of electrical discharge. The effect on discharge response from shape-related field enhancement is investigated through simulated field distribution and experimental current response for devices with design variations in electrode shape. Initial Townsend discharges, between 50 pA and 400 pA, transitioned to a second stage of 2 nA to 20 nA when the applied voltage increased 13% to 21% above the initial breakdown voltage. © 2008 IOP Publishing Ltd.
Total ionizing dose and single event effects hardness assurance qualification issues for microelectronics
IEEE Transactions on Nuclear Science
The radiation effects community has developed a number of hardness assurance test guidelines to assess and assure the radiation hardness of integrated circuits for use in space and/or high-energy particle accelerator applications. These include test guidelines for total dose hardness assurance qualification and single event effects (SEE) qualification. In this work, issues associated with these hardness assurance test guidelines are discussed. For total dose qualification, the main test methodologies used in the U.S. and Europe are reviewed and differences between the guidelines are discussed. In addition, some key issues that must be considered when performing total dose hardness assurance testing are addressed. Following these discussions we review some emerging issues relevant to SEE device qualification that are not covered in present SEE test guidelines. The hardness assurance implications of these issues are addressed. © 2008 IEEE.
Correlated piezoelectric and electrical properties in individual ZnO nanorods
Nano Letters
Quantitative STEM-EDS spectrum imaging of phase transformations in (Pb, La)(Zr, Ti)O3
Microscopy and Microanalysis
Abstract not provided.
Multi-technique approach to understanding phase transformations in a precious metal alloy
Microscopy and Microanalysis
Abstract not provided.
Long-term corrosion testing pan
This document describes the testing and facility requirements to support the Yucca Mountain Project long-term corrosion testing needs. The purpose of this document is to describe a corrosion testing program that will (a) reduce model uncertainty and variability, (b) reduce the reliance upon overly conservative assumptions, and (c) improve model defensibility. Test matrices were developed for 17 topical areas (tasks): each matrix corresponds to a specific test activity that is a subset of the total work performed in a task. A future document will identify which of these activities are considered to be performance confirmation activities. Detailed matrices are provided for FY08, FY09 and FY10 and rough order estimates are provided for FY11-17. Criteria for the selection of appropriate test facilities were developed through a meeting of Lead Lab and DOE personnel on October 16-17, 2007. These criteria were applied to the testing activities and recommendations were made for the facility types appropriate to carry out each activity. The facility requirements for each activity were assessed and activities were identified that can not be performed with currently available facilities. Based on this assessment, a total of approximately 10,000 square feet of facility space is recommended to meet all future testing needs, given that all testing is consolidated to a single location. This report is a revision to SAND2007-7027 to address DOE comments and add a series of tests to address NWTRB recommendations.
New paradigm : controlling initiation phase is necessary for optimization of wire-array z-pinch performance
Abstract not provided.
EPANET-BAM: Water Quality Modeling with Incomplete Mixing in Pipe Junctions (PowerPoint Presentation)
Abstract not provided.
West Pearl Queen CO2 sequestration pilot test and modeling project 2006-2008
The West Pearl Queen is a depleted oil reservoir that has produced approximately 250,000 bbl of oil since 1984. Production had slowed prior to CO{sub 2} injection, but no previous secondary or tertiary recovery methods had been applied. The initial project involved reservoir characterization and field response to injection of CO{sub 2}; the field experiment consisted of injection, soak, and venting. For fifty days (December 20, 2002, to February 11, 2003) 2090 tons of CO{sub 2} were injected into the Shattuck Sandstone Member of the Queen Formation at the West Pearl Queen site. This technical report highlights the test results of the numerous research participants and technical areas from 2006-2008. This work included determination of lateral extents of the permeability units using outcrop observations, core results, and well logs. Pre- and post-injection 3D seismic data were acquired. To aid in interpreting seismic data, we performed numerical simulations of the effects of CO{sub 2} replacement of brine where the reservoir model was based upon correlation lengths established by the permeability studies. These numerical simulations are not intended to replicate field data, but to provide insight of the effects of CO{sub 2}.
Important Factors for Computational Modeling of UV Disinfection Systems
Abstract not provided.
Characterization of Magnetite Nanoparticles for SQUID-relaxometry and Magnetic Needle Biopsy
Journal of Magnetism and Magnetic Materials
Abstract not provided.
Simulations of Radiation Dose-Rate Sensitivity of Bipolar Transistors
IEEE Transactions on Nuclear Science
Abstract not provided.
Low Temperature Sintering of PNSZT
Abstract not provided.
Analysis of NO structure in a methane-air edge flame
We present computations of a methane-air edge flame stabilized against an incoming flow mixing layer, using detailed methane-air chemistry. We analyze the computed edge flame, with a focus on NO-structure. We examine the spatial distribution of NO and its production/consumption rate. We investigate the breakdown of the NO source term among the thermal, prompt, N{sub 2}O, and NO{sub 2} pathways. We examine the contributions of the four pathways at different locations, as the edge flame structure changes with downstream distance, tending to a classical diffusion flame structure. We also examine the dominant reaction flux contributions in each pathway. We compare the results to those in premixed, non-premixed, and opposed-jet triple flames.
Validation & Verification and Uncertainty Quantification at Sandia
Abstract not provided.
Optimization on Manifolds: Problems and Solutions
Abstract not provided.
Introduction to Multigrid Methods
Abstract not provided.
The PageRank Derby
Abstract not provided.
Numerical Examination of Two-Dimensional Smolder Structure in Polyurethane Foam
Abstract not provided.
Some Thoughts on How to Implement the Educational Programme in Nuclear Security
Abstract not provided.
Quantifiable and objective approach to organizational performance enhancement
Abstract not provided.
Post-irradiation Annealing Mechanisms of Defects Generated in Hydrogenated Bipolar Oxides
IEEE Transactions on Nuclear Science
Abstract not provided.
Pulsed Laser Single-Event Effects in Highly Scaled CMOS Technologies in the Presence of Dense Metal Coverage
IEEE Transactions on Nuclear Science
Abstract not provided.
Perspectives on verification, validation, and quantification of margins and uncertainties
Abstract not provided.
Investigation of the Propagation Induced Pulse Broadening (PIPB) Effect on Single Event Transients in SOI and Bulk Inverter Chains
IEEE Transactions on Nuclear Science
Abstract not provided.
Development of Energetic Probe Radiation with Z-Petawatt
Abstract not provided.
Comprehensive Debris Mitigation Technique for a Petawatt Laser Shot into Sandia's Z-Accelerator
Abstract not provided.
Gain Narrowing Compensation in Hybrid OPCPA Systems
Abstract not provided.
Transitions to Transistors
Abstract not provided.
Immersive Simulation Environment for Critical Asset Protection (ISECAP)
Abstract not provided.
Post-CMOS Compatible Aluminum Nitride Resonant MEMS Accelerometers
Post-CMOS Compatible Aluminum Nitride Resonant MEMS Accelerometers
Abstract not provided.
Ku-band Six-bit RF MEMS Time Delay Netwokr
Abstract not provided.
Bayesian inference of epidemiological characteristics in a partially observed epidemic
Abstract not provided.
Long length scale-up of all solution-deposited coated conductors
Abstract not provided.
A Comparison of Aqueous and Non-aqueous Soft-Chemical Syntheses of Lithium Niobate and Lithium Tantalate Powders
Journal of Materials Chemistry
Abstract not provided.