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Modifications to the Finnigan MAT 271 mass spectrometer in the Inorganic Gas Analysis Lab

Cordes, G.T.

This document presents an overview of the modifications that were done to the Finnigan MAT 271 mass spectrometer used in the Dept. 1823 Inorganic Gas Analysis Lab. Among the alterations to the spectrometer were addition of a new computer, interfaces to the power supply, addition of a multimeter and introduction of a Graphical User Interface software system to run the instrument. The impact of these improvements is also discussed. The appendix details a generic procedure for operating the instrument.

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Report of a technical evaluation panel on the use of beryllium for ITER plasma facing material and blanket breeder material

Watson, Robert D.

Beryllium because of its low atomic number and high thermal conductivity, is a candidate for both ITER first wall and divertor surfaces. This study addresses the following: why beryllium; design requirements for the ITER divertor; beryllium supply and unirradiated physical/mechanical property database; effects of irradiation on beryllium properties; tritium issues; beryllium health and safety; beryllium-coolant interactions and safety; thermal and mechanical tests; plasma erosion of beryllium; recommended beryllium grades for ITER plasma facing components; proposed manufacturing methods to produce beryllium parts for ITER; emerging beryllium materials; proposed inspection and maintenance techniques for beryllium components and coatings; time table and costs; and the importance of integrating materials and manufacturing personnel with designers.

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A cost-effective adverse-weather precision guidance system

Fellerhoff, R.; Burgett, S.

This SAND report documents the results of an LDRD project undertaken to study the accuracy of terrain-aided navigation coupled with highly accurate topographic maps. A revolutionary new mapping technology, interferometric synthetic aperture radar (IFSAR), has the ability to make terrain maps of extremely high accuracy and spatial resolution, more than an order of magnitude better than currently available DMA map products. Using a laser altimeter and the Sandia Labs Twin Otter Radar Testbed, fix accuracies of less than 3 meters CEP were obtained over urban and natural terrain regions.

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Aging, stressing and solderability of electroplated and electroless copper

Sorensen, N.R.; Hosking, F.M.

Organic inhibitors can be used to prevent corrosion of metals have application in the electronics industry as solderability preservatives. We have developed a model to describe the action of two inhibitors (benzotriazole and imidazole) during the environmental aging and soldering process. The inhibitors bond with the metal surface and form a barrier that prevents or retards oxidation. At soldering temperatures, the metal-organic complex breaks down leaving an oxide-free metal surface that allows excellent wetting by the molten solder. The presence of the inhibitor retards the wetting rate relative to clean copper but provides a vast improvement relative to oxidized copper.

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Ultra-high-speed optical and electronic distributed devices

Hietala, Vincent M.

This report summarizes work on the development of ultra-high-speed semiconductor optical and electronic devices. High-speed operation is achieved by velocity matching the input stimulus to the output signal along the device`s length. Electronic devices such as field-effect transistors (FET`s), should experience significant speed increases by velocity matching the electrical input and output signals along the device. Likewise, optical devices, which are typically large, can obtain significant bandwidths by velocity matching the light being generated, detected or modulated with the electrical signal on the device`s electrodes. The devices discussed in this report utilize truly distributed electrical design based on slow-wave propagation to achieve velocity matching.

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Characteristics and development report for the SA3871 Intent Controller application specific integrated circuit (ASIC)

Simpson, R.L.; Meyer, B.T.

This report describes the design and development activities that were involved in the SA3871 Intent Controller ASIC. The SA3871 is a digital gate array component developed for the MC4396 Trajectory Sensing Signal Generator for use in the B61-3/4/10 system as well as a possible future B61-MAST system.

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A process for the agile product realization of electro-mechanical devices

Forsythe, James C.

This paper describes a product realization process developed at Sandia National Laboratories by the A-PRIMED project that integrates many of the key components of ``agile manufacturing`` into a complete, step-by-step, design-to-production process. For three separate product realization efforts, each geared to a different set of requirements, A-PRIMED demonstrated product realization of a custom device in less than a month. A-PRIMED used a discriminator (a precision electro-mechanical device) as the demonstration device, but the process is readily adaptable to other electro-mechanical products. The process begins with a qualified design parameter space. From that point, the product realization process encompasses all facets of requirements development, analysis and testing, design, manufacturing, robotic assembly and quality assurance, as well as product data management and concurrent engineering. In developing the product realization process, A-PRIMED employed an iterative approach whereby after each of three builds, the process was reviewed and refinements made on the basis of lessons learned. This paper describes the integration of project functions and product realization technologies, with references to reports detailing specific facets of the overall process. The process described herein represents the outcome of an empirically-based process development effort that on repeated iterations, was proven successful.

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Renewable energy load assessment for Boquillas Del Carmen Coahuila, Mexico

Foster, R.

This report outlines the estimates that were made in 1992 of the potential load requirements for Boquillas del Carmen, a small Mexican village on the northern border of the state of Coahuila, Mexico near Big Bend National Park in southern Texas. The study was made to help determine the possibility that village might be electrified by solar or wind energy. Various estimates of are given of the potential load based on estimates ranging from basic use of lights, radio, television, and small household appliances to microwave ovens, refrigerators, and direct evaporative coolers. The low-energy consumption case was estimated to be at 23.0 kWh/month per residence per month, and the high-energy consumption case (with cooling) was 140.7 kWh/month per residence. On average, the typical residence is occupied by five individuals.

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CHAPARRAL: A library for solving large enclosure radiation heat transfer problems

Glass, Micheal W.

Large, three-dimensional enclosure radiation beat transfer problems place a heavy demand on computing resources such as computational cycles, memory requirements, disk I/O, and disk space usage. This is primarily due to the computational and memory requirements associated with the view factor calculation and subsequent access of the view factor matrix during solution of the radiosity matrix equation. This is a fundamental problem that constrains Sandia`s current modeling capabilities. Reducing the computational and memory requirements for calculating and manipulating view factors would enable an analyst to increase the level of detail at which a body could be modeled and would have a major impact on many programs at Sandia such as weapon and transportation safety programs, component survivability programs, energy programs, and material processing programs. CHAPARRAL is a library package written to address these problems and is specifically tailored towards the efficient solution of extremely large three-dimensional enclosure radiation heat transfer problems.

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Unsaturated-zone fast-path flow calculations for Yucca Mountain groundwater travel time analyses (GWTT-94)

Arnold, Bill W.

Evaluation of groundwater travel time (GWTT) is required as part of the investigation of the suitability of Yucca Mountain as a potential high-level nuclear-waste repository site. The Nuclear Regulatory Commission`s GWTT regulation is considered to be a measure of the intrinsic ability of the site to contain radionuclide releases from the repository. The work reported here is the first step in a program to provide an estimate of GWTT at the Yucca Mountain site in support of the DOE`s Technical Site Suitability and as a component of a license application. Preliminary estimation of the GWTT distribution in the unsaturated zone was accomplished using a numerical model of the physical processes of groundwater flow in the fractured, porous medium of the bedrock. Based on prior investigations of groundwater flow at the site, fractures are thought to provide the fastest paths for groundwater flow; conditions that lead to flow in fractures were investigated and simulated. Uncertainty in the geologic interpretation of Yucca Mountain was incorporated through the use of geostatistical simulations, while variability of hydrogeologic parameters within each unit was accounted for by the random sampling of parameter probability density functions. The composite-porosity formulation of groundwater flow was employed to simulate flow in both the matrix and fracture domains. In this conceptualization, the occurrence of locally saturated conditions within the unsaturated zone is responsible for the initiation of fast-path flow through fractures. The results of the GWTT-94 study show that heterogeneity in the hydraulic properties of the model domain is an important factor in simulating local regions of high groundwater saturation. Capillary-pressure conditions at the surface boundary influence the extent of the local saturation simulated.

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Leveraging limited research and development (R&D) resources in the public sector

Senglaub, Michael E.

Mission-directed public-sector research facilities are experiencing increasingly severe budget environments while seeing expanding missions and responsibilities. In an effort to identify research leveraging methodologies an information search was conducted in conjunction with some efforts to find the proper links to systems engineering fundamentals. The result is an initial model for use in a preconcept/phase-1 engineering design organization, with a goal of improving the organizations performance.

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What is systems engineering?

Bahill, A.T.

Systems Engineering is an interdisciplinary process that ensures that the customers` needs are satisfied throughout a system`s entire life cycle. This process includes: understanding customer needs; stating the problem; specifying requirements; defining performance and cost measures, prescribing tests, validating requirements, conducting design reviews, exploring alternative concepts, sensitivity analyses, functional decomposition, system design, designing and managing interfaces, system integration, total system test, configuration management, risk management, reliability analysis; total quality management; project management; and documentation. Material for this paper was gathered from senior Systems Engineers at Sandia National Laboratories.

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Systems engineering: A problem of perception

Senglaub, Michael E.

The characterization of systems engineering as a discipline, process, procedure or a set of heuristics will have an impact on the implementation strategy, the training methodology, and operational environment. The systems engineering upgrade activities in the New Mexico Weapons Development Center and a search of systems engineering related information provides evidence of a degree of ambiguity in this characterization of systems engineering. A case is made in this article for systems engineering being the engineering discipline applied to the science of complexity. Implications of this characterization and some generic issues are delineated with the goal of providing an enterprise with a starting point for developing its business environment.

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Inside Sandia

Goetsch, Robert S.

Inside Sandia, published every other month, presents technological advances made at Sandia National Laboratories. The articles in IS will cover a wide range of technologies that have been developed at Sandia. Some of the areas that will receive a good deal of attention in these pages include information sciences, manufacturing and robotics, environmental science, energy research, transportation technology, and biomedical engineering. All of this work is done to further Sandia National Laboratories` missions in defense, energy, and environmental research, and technology transfer.

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Large bipolarons and superconductivity

Journal of Superconductivity

Emin, David J.

Superconductivity has long been speculated to result from charge carriers paired as mobile charged bosons. Although the pairing of carriers as small (single-site) bipolarons is known, small bipolarons readily localize. By contrast, large (multi-site) bipolarons, in analogy with large polarons, should be mobile. It is shown that large bipolarons can form in solids with very displaceable ions, e.g., many oxides. Large-polaronic (but not small-polaronic) carriers produce absorption spectra like the carrier-induced absorptions observed in cuprates. Redistribution of the self-trapped carriers of large bipolarons among sites of carriers' molecular orbitals in response to atomic motions lowers phonon frequencies. The dependence of the phonon zero-point energy on the spatial distribution of large bipolarons produces a phonon-mediated attraction between them. This dynamic quantum-mechanical attraction fosters the condensation of large bipolarons into a liquid. Superconductivity can result when the large-bipolarons' groundstate remains liquid rather than solidifying. © 1995 Plenum Publishing Corporation.

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The Spent Fuel Safety Experiment

Harms, Gary A.

The Department of Energy is conducting an ongoing investigation of the consequences of taking fuel burnup into account in the design of spent fuel transportation packages. A series of experiments, collectively called the Spent Fuel Safety Experiment (SFSX), has been devised to provide integral benchmarks for testing computer-generated predictions of spent fuel behavior. A set of experiments is planned in which sections of unirradiated fuel rods are interchanged with similar sections of spent PWR fuel rods in a critical assembly. By determining the critical size of the arrays, one can obtain benchmark data for comparison with criticality safety calculations. The SFSX provides a direct measurement of the reactivity effects of spent PWR fuel using a well-characterized, spent fuel sample. The SFSX also provides an experimental measurement of the end-effect, i.e., the reactivity effect of the variation of the burnup profile at the ends of PWR fuel rods. The design of the SFSX is optimized to yield accurate benchmark measurements of the effects of interest, well above experimental uncertainties.

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Hypervelocity impact testing of spacecraft optical sensors

Browning, John S.

Hypervelocity tests of spacecraft optical sensors were conducted to determine if the optical signature from an impact inside the optical sensor sunshade resembled signals that have been observed on-orbit. Impact tests were conducted in darkness and with the ejected debris illuminated. The tests were conducted at the Johnson Space Center Hypervelocity Impact Test Facility. The projectile masses and velocities that may be obtained at the facility are most representative of the hypervelocity particles thought to be responsible for a group of anomalous optical sensors responses that have been observed on-orbit. The projectiles are a few micrograms, slightly more massive than the microgram particles thought to be responsible for the signal source. The test velocities were typically 7.3 km/s, which are somewhat slower than typical space particles.

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Empirical verification of fine-motoion planning theories

Brost, Randolph

Successful robot systems must employ actions that are robust in the face of task uncertainty. Toward this end, Lozano-Perez, Mason, and Taylor developed a model of manipulation tasks that explicitly considers task uncertainty. In this paper we study the utility of this model applied to real-world tasks. We report the results of two experiments that highlight the strengths and weaknesses of the LMT approach. The first experiment showed that the LMT formalism can successfully plan solutions for a complex real-world task. The second experiment showed a task that the formalism is fundamentally incapable of solving.

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Diffusion in polycrystalline microstructures

Swiler, T.P.; Holm, E.A.

Mass transport properties are important in polycrystalline materials used as protective films. Traditionally, such properties have been studied by examining model polycrystalline structures, such as a regular array of straight grain boundaries. However, these models do not account for a number of features of real grain ensembles, including the grain size distribution and the topological aspects of grain boundaries. In this study, a finite difference scheme is developed to study transient and steady-state mass transport through realistic two-dimensional polycrystalline microstructures. Effects of microstructural parameters such as average grain size and grain boundary topology are examined, as are effects due to limits of the model.

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A numerical model of 2-D sloshing of pseudo-viscous liquids in horizontally accelerated rectangular containers

Romero, Vicente J.

A numerical model for simulating the transient nonlinear behavior of 2-D viscous sloshing flows in rectangular containers subjected to arbitrary horizontal accelerations is presented. The potential-flow formulation uses Rayleigh damping to approximate the effects of viscosity, and Lagrangian node movement is used to accommodate violent sloshing motions. A boundary element approach is used to efficiently handle the time-changing fluid geometry. Additionally, a corrected equation is presented for the constraint condition relating normal and tangential derivatives of the velocity potential where the fluid free surface meets the rigid container wall. The numerical model appears to be more accurate than previous sloshing models, as determined by comparison against exact analytic solutions and results of previously published models.

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Overview of criminal justice projects at Sandia National Laboratories

Spencer, D.S.

The criminal justice projects at SNL include three projects for the National Institute of Justice (smart gun, restraining foam, aqueous foam, corrections perimeter), a Southwest Border study, and one involving corrections agencies. It is concluded that the national technologies developed to protect nuclear and other high value assets have enormous potential for application to crime and personal safety; the difficulty lies in simplifying the technology transfer and making the new systems affordable.

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Phosphors for flat panel emissive displays

Anderson, M.T.

An overview of emissive display technologies is presented. Display types briefly described include: cathode ray tubes (CRTs), field emission displays (FEDs), electroluminescent displays (ELDs), and plasma display panels (PDPs). The critical role of phosphors in further development of the latter three flat panel emissive display technologies is outlined. The need for stable, efficient red, green, and blue phosphors for RGB fall color displays is emphasized.

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A proposed methodology for computational fluid dynamics code verification, calibration, and validation

Aeschliman, D.P.

Verification, calibration, and validation (VCV) of Computational Fluid Dynamics (CFD) codes is an essential element of the code development process. The exact manner in which code VCV activities are planned and conducted, however, is critically important. It is suggested that the way in which code validation, in particular, is often conducted--by comparison to published experimental data obtained for other purposes--is in general difficult and unsatisfactory, and that a different approach is required. This paper describes a proposed methodology for CFD code VCV that meets the technical requirements and is philosophically consistent with code development needs. The proposed methodology stresses teamwork and cooperation between code developers and experimentalists throughout the VCV process, and takes advantage of certain synergisms between CFD and experiment. A novel approach to uncertainty analysis is described which can both distinguish between and quantify various types of experimental error, and whose attributes are used to help define an appropriate experimental design for code VCV experiments. The methodology is demonstrated with an example of laminar, hypersonic, near perfect gas, 3-dimensional flow over a sliced sphere/cone of varying geometrical complexity.

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Results 95526–95550 of 99,299
Results 95526–95550 of 99,299