It was discovered that MgO or Mg(OH){sub 2} when it reacts with water is a very strong sorbent for arsenic. Distribution constants, or K{sub d} values, are as high as 1 x 10{sup 6} L/mole. In this work, Mg(OH){sub 2} and other compounds have been investigated as sorbents for arsenic and other contaminants. This work has resulted in several major accomplishments including: (1) design, construction, and testing of a pressure sand filter to remove Mg(OH){sub 2} after it has sorbed arsenic from water, (2) stabilization of Mg(OH){sub 2} as a Sorrel's cement against reaction with carbonate that results in MgCO{sub 3} formation decreasing the efficiency of Mg(OH){sub 2} to sorb arsenic, and (3) the development of a new, very promising sorbent for arsenic based on zirconium. Zirconium is an environmentally benign material found in many common products such as toothpaste. It is currently used in water treatment and is very inexpensive. In this work, zirconium has been bonded to activated carbon, zeolites, sand and montmorillonite. Because of its high charge in ionic form (+6), zirconium is a strong sorbent for many anions including arsenic. In equilibrium experiments arsenic concentrations in water were reduced from 200 ppb to less than 1 ppb in less than 1 minute of contact time. Additionally, analytical methods for detecting arsenic in water have also been investigated. Various analytical techniques including HPLC, AA and ICP-MS are used for quantification of arsenic. Due to large matrix interferences HPLC and AA techniques are not very selective and are time consuming. ICP-MS is highly efficient, requires a low sample volume and has a high tolerance for interferences. All these techniques are costly and require trained staff, and with the exception of ICP-MS, these methods cannot be used at low ppb arsenic concentration without using a pre-concentration step. An alternative to these traditional techniques is to use a colorimetric method based on leucocrystal violet dye interaction with iodine. This method has been adapted in our facility for quantifying arsenic concentrations down to 14 ppb.
Aspen, a powerful economic modeling tool that uses agent modeling and genetic algorithms, can accurately simulate the economy. In it, individuals are hired by firms to produce a good that households then purchase. The firms decide what price to charge for this good, and based on that price, the households determine which firm to purchase from. We will attempt to discover the Nash Equilibrium price found in this model under two different methods of determining how many orders each firm receives. To keep it simple, we will assume there are only two firms in our model, and that these firms compete for the sale of one identical good.
This report outlines our work on the integration of high efficiency photonic lattice structures with MEMS (MicroElectroMechanical Systems). The simplest of these structures were based on 1-D mirror structures. These were integrated into a variety of devices, movable mirrors, switchable cavities and finally into Bragg fiber structures which enable the control of light in at least 2 dimensions. Of these devices, the most complex were the Bragg fibers. Bragg fibers consist of hollow tubes in which light is guided in a low index media (air) and confined by surrounding Bragg mirror stacks. In this work, structures with internal diameters from 5 to 30 microns have been fabricated and much larger structures should also be possible. We have demonstrated the fabrication of these structures with short wavelength band edges ranging from 400 to 1600nm. There may be potential applications for such structures in the fields of integrated optics and BioMEMS. We have also looked at the possibility of waveguiding in 3 dimensions by integrating defects into 3-dimensional photonic lattice structures. Eventually it may be possible to tune such structures by mechanically modulating the defects.
The purpose of this review was to provide insights and information to Sandia National Laboratories' (SNL) Education Council on the state of technical education and training at SNL in order to address the concern that a change in philosophy surrounding education had occurred. To accomplish this, the status of current and past technical training and education programs were compared, and significant changes at SNL were assessed for their impact on education and training. Major changes in education and training are in the advertisement of course offerings, the course delivery methods, and the funding mechanisms for student and instructor time as well as course costs. The significant changes in SNL which influenced technical training and education are the considerable increase in mandatory or compliance training, a fundamental shift in SNL's management structure from an institutional structure to a more business-like, project-budgeted structure, and the change in SNL's mission at the end of the Cold War. These changes contributed to less time for technical training, reduction of training funds, elimination of some training, and a Service Center approach to paying for training. Most importantly, the overall combined effect has resulted in a shift from a strategic to a tactical training approach. The Corporate Training Department (CTD) has maneuvered to accommodate these changes and keep abreast of constantly changing needs.
Sandia National Laboratories has been investigating the use of remotely operated weapon platforms in Department of Energy (DOE) facilities. These platforms offer significant force multiplication and enhancement by enabling near instantaneous response to attackers, increasing targeting accuracy, removing personnel from direct weapon fire, providing immunity to suppressive fire, and reducing security force size needed to effectively respond. Test results of the Telepresent Rapid Aiming Platform (TRAP) from Precision Remotes, Inc. have been exceptional and response from DOE sites and the U.S. Air Force is enthusiastic. Although this platform performs comparably to a trained marksman, the target acquisition speeds are up to three times longer. TRAP is currently enslaved to a remote operator's joystick. Tracking moving targets with a joystick is difficult; it dependent upon target range, movement patterns, and operator skill. Even well-trained operators encounter difficulty tracking moving targets. Adding intelligent targeting capabilities on a weapon platform such as TRAP would significantly improve security force response in terms of effectiveness and numbers of responders. The initial goal of this project was to integrate intelligent targeting with TRAP. However, the unavailability of a TRAP for laboratory purposes drove the development of a new platform that simulates TRAP but has a greater operating range and is significantly faster to reposition.
The Global Energy Futures Model (GEFM) is a demand-based, gross domestic product (GDP)-driven, dynamic simulation tool that provides an integrated framework to model key aspects of energy, nuclear-materials storage and disposition, environmental effluents from fossil and non fossil energy and global nuclear-materials management. Based entirely on public source data, it links oil, natural gas, coal, nuclear and renewable energy dynamically to greenhouse-gas emissions and 12 other measures of environmental impact. It includes historical data from 1990 to 2000, is benchmarked to the DOE/EIA/IEO 2001 [5] Reference Case for 2000 to 2020, and extrapolates energy demand through the year 2050. The GEFM is globally integrated, and breaks out five regions of the world: United States of America (USA), the Peoples Republic of China (China), the former Soviet Union (FSU), the Organization for Economic Cooperation and Development (OECD) nations excluding the USA (other industrialized countries), and the rest of the world (ROW) (essentially the developing world). The GEFM allows the user to examine a very wide range of ''what if'' scenarios through 2050 and to view the potential effects across widely dispersed, but interrelated areas. The authors believe that this high-level learning tool will help to stimulate public policy debate on energy, environment, economic and national security issues.
Recent terrorist attacks in the United States have increased concerns about potential national security consequences from energy supply disruptions. The purpose of this Laboratory Directed Research & Development (LDRD) is to develop a high-level dynamic simulation model that would allow policy makers to explore the national security consequences of major US. energy supply disruptions, and to do so in a way that would integrate energy, economic and environmental components. The model allows exploration of potential combinations of demand-driven energy supplies that meet chosen policy objectives, including: Mitigating economic losses, measured in national economic output and employment levels, due to terrorist activity or forced outages of the type seen in California; Control of greenhouse gas levels and growth rates; and Moderating US. energy import requirements. This work has built upon the Sandia US. Energy and greenhouse Gas Model (USEGM) by integrating a macroeconomic input-output framework into the model, adding the capability to assess the potential economic impact of energy supply disruptions and the associated national security issues. The economic impacts of disruptions are measured in terms of lost US. output (e.g., GDP, sectoral output) and lost employment, and are assessed either at a broad sectoral level (3 sectors) or at a disaggregated level (52 sectors). In this version of the model, physical energy disruptions result in quantitative energy shortfalls, and energy prices are not permitted to rise to clear the markets.
This LDRD project has involved the development and application of Sandia's massively parallel materials modeling software to several significant biophysical systems. They have been successful in applying the molecular dynamics code LAMMPS to modeling DNA, unstructured proteins, and lipid membranes. They have developed and applied a coupled transport-molecular theory code (Tramonto) to study ion channel proteins with gramicidin A as a prototype. they have used the Towhee configurational bias Monte-Carlo code to perform rigorous tests of biological force fields. they have also applied the MP-Sala reacting-diffusion code to model cellular systems. Electroporation of cell membranes has also been studied, and detailed quantum mechanical studies of ion solvation have been performed. In addition, new molecular theory algorithms have been developed (in FasTram) that may ultimately make protein solvation calculations feasible on workstations. Finally, they have begun implementation of a combined molecular theory and configurational bias Monte-Carlo code. They note that this LDRD has provided a basis for several new internal (e.g. several new LDRD) and external (e.g. 4 NIH proposals and a DOE/Genomes to Life) proposals.
As demonstrated by the anthrax attack through the United States mail, people infected by the biological agent itself will give the first indication of a bioterror attack. Thus, a distributed information system that can rapidly and efficiently gather and analyze public health data would aid epidemiologists in detecting and characterizing emerging diseases, including bioterror attacks. We propose using clusters of adverse health events in space and time to detect possible bioterror attacks. Space-time clusters can indicate exposure to infectious diseases or localized exposure to toxins. Most space-time clustering approaches require individual patient data. To protect the patient's privacy, we have extended these approaches to aggregated data and have embedded this extension in a sequential probability ratio test (SPRT) framework. The real-time and sequential nature of health data makes the SPRT an ideal candidate. The result of space-time clustering gives the statistical significance of a cluster at every location in the surveillance area and can be thought of as a ''health-index'' of the people living in this area. As a surrogate to bioterrorism data, we have experimented with two flu data sets. For both databases, we show that space-time clustering can detect a flu epidemic up to 21 to 28 days earlier than a conventional periodic regression technique. We have also tested using simulated anthrax attack data on top of a respiratory illness diagnostic category. Results show we do very well at detecting an attack as early as the second or third day after infected people start becoming severely symptomatic.
Thermoluminescent dosimeters (TLDs), particularly CaF{sub 2}:Mn, are often used as photon dosimeters in mixed (n/{gamma}) field environments. In these mixed field environments, it is desirable to separate the photon response of a dosimeter from the neutron response. For passive dosimeters that measure an integral response, such as TLDs, the separation of the two components must be performed by post-experiment analysis because the TLD reading system cannot distinguish between photon and neutron produced response. Using a model of an aluminum-equilibrated TLD-400 chip, a systematic effort has been made to analytically determine the various components that contribute to the neutron response of a TLD reading. The calculations were performed for five measured reactor neutron spectra and one theoretical thermal neutron spectrum. The five measured reactor spectra all have dosimetry quality experimental values for aluminum-equilibrated TLD-400 chips. Calculations were used to determined the percentage of the total TLD response produced by neutron interactions in the TLD and aluminum equilibrator. These calculations will aid the Sandia National Laboratories-Radiation Metrology Laboratory (SNL-RML) in the interpretation of the uncertainty for TLD dosimetry measurements in the mixed field environments produced by SNL reactor facilities.
Buried landmines are often detected through the chemical signature in the air above the soil surface by mine detection dogs. Environmental processes play a significant role in the chemical signature available for detection. Due to the shallow burial depth of landmines, the weather influences the release of chemicals from the landmine, transport through the soil to the surface, and degradation processes in the soil. The effect of weather on the landmine chemical signature from a PMN landmine was evaluated with the T2TNT code for Kabul, Afghanistan. Results for TNT and DNT gas-phase and soil solid-phase concentrations are presented as a function of time of the day and time of the year.
This report describes research and development of methods to couple vastly different subsystems and physical models and to encapsulate these methods in a Java{trademark}-based framework. The work described here focused on developing a capability to enable design engineers and safety analysts to perform multifidelity, multiphysics analyses more simply. In particular this report describes a multifidelity algorithm for thermal radiative heat transfer and illustrates its performance. Additionally, it describes a module-based computer software architecture that facilitates multifidelity, multiphysics simulations. The architecture is currently being used to develop an environment for modeling the effects of radiation on electronic circuits in support of the FY 2003 Hostile Environments Milestone for the Accelerated Strategic Computing Initiative.
The quantitative analysis of microstructure and sequence distribution in polysiloxane copolymers using high-resolution solution {sup 29}Si NMR is reported. Copolymers containing dimethylsiloxane (DMS) and diphenysiloxane (DPS) monomer units prepared with either high vinyl content (HVM) or low vinyl content (LVM) were analyzed. The average run length (R{sub exp}), the number average sequence length (l{sub A}, l{sub B}), along with the various linkage probabilities (p{sub AA}, p{sub AB}, p{sub BA}, and p{sub BB}) were determined for different production lots of the LVM97 and HVM97 samples to address the lot variability of microstructure in these materials.
In an effort to recruit and retain skilled workers in the Manufacturing Science and Technology Center (14000), an innovative and highly diverse team at Sandia National Laboratories and the U.S. Department of Energy joined with concerned community constitutents, such as Albuquerque Technical Vocational Institute and the Albuquerque Public Schools, to offer mentoring and on-the-job training to qualified students in high schools and community colleges. Now, within several years of its inception, the educational program called the Advanced Manufacturing Trades Training Program is a model in the community and the nation, while enabling Sandia to have valuable trained and skilled employees to meet its national mission and workforce demands.
This manual describes the use of the Xyce Parallel Electronic Simulator code for simulating electrical circuits at a variety of abstraction levels. The Xyce Parallel Electronic Simulator has been written to support,in a rigorous manner, the simulation needs of the Sandia National Laboratories electrical designers. As such, the development has focused on improving the capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers. (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. (3) A client-server or multi-tiered operating model wherein the numerical kernel can operate independently of the graphical user interface (GUI). (4) Object-oriented code design and implementation using modern coding-practices that ensure that the Xyce Parallel Electronic Simulator will be maintainable and extensible far into the future. The code is a parallel code in the most general sense of the phrase--a message passing parallel implementation--which allows it to run efficiently on the widest possible number of computing platforms. These include serial, shared-memory and distributed-memory parallel as well as heterogeneous platforms. Furthermore, careful attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved even as the number of processors grows. Another feature required by designers is the ability to add device models, many specific to the needs of Sandia, to the code. To this end, the device package in the Xyce Parallel Electronic Simulator is designed to support a variety of device model inputs. These input formats include standard analytical models, behavioral models and look-up tables. Combined with this flexible interface is an architectural design that greatly simplifies the addition of circuit models. One of the most important contribution Xyce makes to the designers at Sandia National Laboratories is in providing a platform for computational research and development aimed specifically at the needs of the Laboratory. With Xyce, Sandia now has an ''in-house''capability with which both new electrical (e.g., device model development) and algorithmic (e.g., faster time-integration methods) research and development can be performed. Furthermore, these capabilities will then be migrated to the end users.
Fixtures are tools used to hold parts in specific positions and orientations so that certain manufacturing steps can be carried out within required accuracies. Despite the importance of fixtures in the production of expensive devices at Sandia National Laboratories, there is little in-house expertise in mathematical design issues associated with fixtures. As a result, fixtures typically do not work as intended when they are first manufactured. Thus, an inefficient and expensive trial-and-error approach must be utilized. This design methodology adversely impacts important mission duties of Sandia National Laboratories, such as the production of neutron generators. The work performed under the support of this LDRD project took steps toward providing mechanical designers with software tools based on rigorous analytical techniques for dealing with fixture stability and tolerance stack-up.
This report presents a detailed multi-methods comparison of the spatial errors associated with finite difference, finite element and finite volume semi-discretizations of the scalar advection-diffusion equation. The errors are reported in terms of non-dimensional phase and group speeds, discrete diffusivity, artificial diffusivity, and grid-induced anisotropy. It is demonstrated that Fourier analysis (aka von Neumann analysis) provides an automatic process for separating the spectral behavior of the discrete advective operator into its symmetric dissipative and skew-symmetric advective components. Further it is demonstrated that streamline upwind Petrov-Galerkin and its control-volume finite element analogue, streamline upwind control-volume, produce both an artificial diffusivity and an artificial phase speed in addition to the usual semi-discrete artifacts observed in the discrete phase speed, group speed and diffusivity. For each of the numerical methods considered, asymptotic truncation error and resolution estimates are presented for the limiting cases of pure advection and pure diffusion. The Galerkin finite element method and its streamline upwind derivatives are shown to exhibit super-convergent behavior in terms of phase and group speed when a consistent mass matrix is used in the formulation. In contrast, the CVFEM method and its streamline upwind derivatives yield strictly second-order behavior. While this work can only be considered a first step in a comprehensive multi-methods analysis and comparison, it serves to identify some of the relative strengths and weaknesses of multiple numerical methods in a common mathematical framework.
BURNCAL is a Fortran computer code designed to aid in analysis, prediction, and optimization of fuel burnup performance in a nuclear reactor. The code uses output parameters generated by the Monte Carlo neutronics code MCNP to determine the isotopic inventory as a function of time and power density. The code allows for multiple fueled regions to be analyzed. The companion code, RELOAD, can be used to shuffle fueled regions or reload regions with fresh fuel. BURNCAL can be used to study the reactivity effects and isotopic inventory as a function of time for a nuclear reactor system. Neutron transmutation, fission, and radioactive decay are included in the modeling of the production and removal terms for each isotope of interest. For a fueled region, neutron transmutation, fuel depletion, fission-product poisoning, actinide generation, and burnable poison loading and depletion effects are included in the calculation. Fueled and un-fueled regions, such as cladding and moderator, can be analyzed simultaneously. The nuclides analyzed are limited only by the neutron cross section availability in the MCNP cross-section library. BURNCAL is unique in comparison to other burnup codes in that it does not use the calculated neutron flux as input to other computer codes to generate the nuclide mixture for the next time step. Instead, BURNCAL directly uses the neutron absorption tally/reaction information generated by MCNP for each nuclide of interest to determine the nuclide inventory for that region. This allows for the full capabilities of MCNP to be incorporated into the calculation and a more accurate and robust analysis to be performed.
An analysis was conducted of the potential for unmanned and unattended robotic technologies for forward-based, immediate response capabilities that enables access and controlled task performance. The authors analyze high-impact response scenarios in conjunction with homeland security organizations, such as the NNSA Office of Emergency Response, the FBI, the National Guard, and the Army Technical Escort Unit, to cover a range of radiological, chemical and biological threats. They conducted an analysis of the potential of forward-based, unmanned and unattended robotic technologies to accelerate and enhance emergency and crisis response by Homeland Defense organizations. Response systems concepts were developed utilizing new technologies supported by existing emerging threats base technologies to meet the defined response scenarios. These systems will pre-position robotic and remote sensing capabilities stationed close to multiple sites for immediate action. Analysis of assembled systems included experimental activities to determine potential efficacy in the response scenarios, and iteration on systems concepts and remote sensing and robotic technologies, creating new immediate response capabilities for Homeland Defense.
The SNL/NM FY2001 SWEIS Annual Review discusses changes in facilities and facility operations that have occurred in selected and notable facilities since source data were collected for the SNL/NM SWEIS (DOE/EIS-0281). The following information is presented: (1) An updated overview of SNL/NM selected and notable facilities and infrastructure capabilities. (2) An overview of SNL/NM environment, safety, and health programs, including summaries of the purpose, operations, activities, hazards, and hazard controls at relevant facilities and risk management methods for SNL/NM. (3) Updated base year activities data, projections of FY2003 and FY2008 activities, together with related inventories, material consumption, emissions, waste, and resource consumption. (4) Appendices summarizing activities and related hazards at SNL/NM individual special, general, and highbay laboratories, and chemical purchases.
Despite many decades of jet-in-crossflow experimentation, a distinct lack of data remains for a supersonic jet exhausting into a subsonic compressible crossflow. The present investigation seeks to address this deficiency by examining the flowfield structure of a Mach 3.73 jet injected transversely from a flat plate into a subsonic compressible freestream. The experimental results described herein include the mean surface pressure field as mapped using static pressure taps on the flat plate and an identification of flow features by employing an oil-based surface flow tracer. The possibility of flow separation within the nozzle itself also is addressed using pressure taps along the nozzle interior wall, as is the asymmetry of the separation line due to the variation of the local backpressure around the perimeter of the nozzle orifice resulting from the jet-in-crossflow interaction. Pressure data both on the flat plate and within the nozzle are presented at numerous angles with respect to the crossflow freestream direction to provide a breadth of measurements throughout the interaction region. Since the data are intended for use in validating computational models, attention is paid to providing details regarding the experimental geometry, boundary conditions, flowfield nonuniformities, and uncertainty analyses. Eight different sets of data are provided, covering a range of values of the jet-to-freestream dynamic pressure ratio from 2.8 to 16.9 and a freestream Mach number range of 0.5 to 0.8.
ALEGRA is an arbitrary Lagrangian-Eulerian finite element code that emphasizes large distortion and shock propagation. This document describes the user input language for the code.
The most widely used algorithm for estimating seismic event hypocenters and origin times is iterative linear least squares inversion. In this paper we review the mathematical basis of the algorithm and discuss the major assumptions made during its derivation. We go on to explore the utility of using Levenberg-Marquardt damping to improve the performance of the algorithm in cases where some of these assumptions are violated. We also describe how location parameter uncertainties are calculated. A technique to estimate an initial seismic event location is described in an appendix.
Mild detonating fuse is an extruded aluminum tube that contains explosive material. Fuse prepared by a new supplier (Company B) exhibited a formability problem and was analyzed to determine the source of that formability problem. The formability problem was associated with cracking of the aluminum tube when it was bent around a small radius. Mild detonating fuse prepared by the existing supplier of product (Company A) did not exhibit a formability problem. The two fuses were prepared using different aluminum alloys. The microstructure and chemical composition of the two aluminum alloys were compared. It was found that the microstructure of the Company A aluminum exhibited clear signs of dynamic recrystallization while the Company B aluminum did not. Recrystallization results in the removal of dislocations associated with work hardening and will dramatically improve formability. Comparison of the chemical composition of the two aluminum alloys revealed that the Company A aluminum contained significantly lower levels of impurity elements (specifically Fe and Si) than the COMPANY B aluminum. It has been concluded that the formability problem exhibited by the COMPANY B material will be solved by using an aluminum alloy with low impurity content such as 1190-H18 or 1199-0.
The Blade Manufacturing Improvement Project explores new, unique and improved materials integrated with innovative manufacturing techniques that promise substantial economic enhancements for the fabrication of wind turbine blades. The primary objectives promote the development of advanced wind turbine blade manufacturing in ways that lower blade costs, cut rotor weight, reduce turbine maintenance costs, improve overall turbine quality and increase ongoing production reliability. Foam Matrix (FMI) has developed a wind turbine blade with an engineered foam core, incorporating advanced composite materials and using Resin Transfer Molding (RTM) processes to form a monolithic blade structure incorporating a single molding tool. Patented techniques are employed to increase blade load bearing capability and insure the uniform quality of the manufactured blade. In production quantities, FMI manufacturing innovations may return a sizable per blade cost reduction when compared to the cost of producing comparable blades with conventional methods.
A probabilistic, risk-based performance-assessment methodology has been developed to assist designers, regulators, and stakeholders in the selection, design, and monitoring of long-term covers for contaminated subsurface sites. This report describes the method, the software tools that were developed, and an example that illustrates the probabilistic performance-assessment method using a repository site in Monticello, Utah. At the Monticello site, a long-term cover system is being used to isolate long-lived uranium mill tailings from the biosphere. Computer models were developed to simulate relevant features, events, and processes that include water flux through the cover, source-term release, vadose-zone transport, saturated-zone transport, gas transport, and exposure pathways. The component models were then integrated into a total-system performance-assessment model, and uncertainty distributions of important input parameters were constructed and sampled in a stochastic Monte Carlo analysis. Multiple realizations were simulated using the integrated model to produce cumulative distribution functions of the performance metrics, which were used to assess cover performance for both present- and long-term future conditions. Performance metrics for this study included the water percolation reaching the uranium mill tailings, radon gas flux at the surface, groundwater concentrations, and dose. Results from uncertainty analyses, sensitivity analyses, and alternative design comparisons are presented for each of the performance metrics. The benefits from this methodology include a quantification of uncertainty, the identification of parameters most important to performance (to prioritize site characterization and monitoring activities), and the ability to compare alternative designs using probabilistic evaluations of performance (for cost savings).
The objective of this heat transfer and fluid flow study is to assess the ability of a computational fluid dynamics (CFD) code to reproduce the experimental results, numerical simulation results, and heat transfer correlation equations developed in the literature for natural convection heat transfer within the annulus of horizontal concentric cylinders. In the literature, a variety of heat transfer expressions have been developed to compute average equivalent thermal conductivities. However, the expressions have been primarily developed for very small inner and outer cylinder radii and gap-widths. In this comparative study, interest is primarily focused on large gap widths (on the order of half meter or greater) and large radius ratios. From the steady-state CFD analysis it is found that the concentric cylinder models for the larger geometries compare favorably to the results of the Kuehn and Goldstein correlations in the Rayleigh number range of about 10{sup 5} to 10{sup 8} (a range that encompasses the laminar to turbulent transition). For Rayleigh numbers greater than 10{sup 8}, both numerical simulations and experimental data (from the literature) are consistent and result in slightly lower equivalent thermal conductivities than those obtained from the Kuehn and Goldstein correlations.
A study has been completed into the RAS features necessary for Massively Parallel Processor (MPP) systems. As part of this research, a use case model was built of how RAS features would be employed in an operational MPP system. Use cases are an effective way to specify requirements so that all involved parties can easily understand them. This technique is in contrast to laundry lists of requirements that are subject to misunderstanding as they are without context. As documented in the use case model, the study included a look at incorporating system software and end-user applications, as well as hardware, into the RAS system.
Three years of large-scale PDE-constrained optimization research and development are summarized in this report. We have developed an optimization framework for 3 levels of SAND optimization and developed a powerful PDE prototyping tool. The optimization algorithms have been interfaced and tested on CVD problems using a chemically reacting fluid flow simulator resulting in an order of magnitude reduction in compute time over a black box method. Sandia's simulation environment is reviewed by characterizing each discipline and identifying a possible target level of optimization. Because SAND algorithms are difficult to test on actual production codes, a symbolic simulator (Sundance) was developed and interfaced with a reduced-space sequential quadratic programming framework (rSQP++) to provide a PDE prototyping environment. The power of Sundance/rSQP++ is demonstrated by applying optimization to a series of different PDE-based problems. In addition, we show the merits of SAND methods by comparing seven levels of optimization for a source-inversion problem using Sundance and rSQP++. Algorithmic results are discussed for hierarchical control methods. The design of an interior point quadratic programming solver is presented.
A distributed reconfigurable micro-robotic system is a collection of unlimited numbers of distributed small, homogeneous robots designed to autonomously organize and reorganize in order to achieve mission-specified geometric shapes and functions. This project investigated the design, control, and planning issues for self-configuring and self-organizing robots. In the 2D space a system consisting of two robots was prototyped and successfully displayed automatic docking/undocking to operate dependently or independently. Additional modules were constructed to display the usefulness of a self-configuring system in various situations. In 3D a self-reconfiguring robot system of 4 identical modules was built. Each module connects to its neighbors using rotating actuators. An individual component can move in three dimensions on its neighbors. We have also built a self-reconfiguring robot system consisting of 9-module Crystalline Robot. Each module in this robot is actuated by expansion/contraction. The system is fully distributed, has local communication (to neighbors) capabilities and it has global sensing capabilities.
A computational method for the prediction of the bursting frequency associated with the coherent streamwise structures in high-speed compressible turbulent boundary layers is presented. The structures are described as wavelike disturbances of the turbulent mean flow. A direct resonance theory is used to determine the frequency of bursting. The resulting hydrodynamic linear stability equations are discretized by using a Chebyshev collocation method. A global numerical method capable of resolving the entire eigenvalue spectrum is used. Realistic turbulent mean velocity and temperature profiles are applied. For all of the compressible turbulent boundary layers calculated, the results show at least one frequency that satisfies the resonance condition. A second frequency can be identified for cases with high Reynolds numbers. An estimate is also made for the profile distribution of the temperature disturbance.
This report describes the development of an ultra-low power spread spectrum receiver based on a programmable surface acoustic wave (SAW) correlator. This work was funded under LDRD 02-26573, Ultra-Low Power Spread Spectrum Receiver. The approach taken in this project uses direct demodulation of a radio frequency (RF) signal from carrier frequency to data frequency. This approach was taken to reduce power consumption and size. The design is based on the technique of correlating the received RF signal with the preprogrammed spreading code. The system requirements, applications, design methodology, and testing results are all documented in the following pages.
Document is the final report for PSP project No. 14402-10-02 entitled ''Improved Manufacturing of MC4531 Mold Bodies Using High-Speed Machining (HSM)''. The basic physics of high speed machining is discussed in detail including multiple vibrational mode machining systems (milling and turning) and the effect of spindle speed regulation on maximizing the depth of cut and metal removal rate of a machining operation. The topics of cutting tests and tap tests are also discussed as well as the use of the HSM assistance software ''Harmonizer''. Results of the application of HSM to the machining of encapsulation molds are explained in detail including cutting test results, new tool speeds and feeds, dimensional and surface finish measurements and a comparison to the original machining operations and cycle times. A 38% improvement in cycle time is demonstrated while achieving a 50% better surface finish than required.
Wireless communication plays an increasing role in military, industrial, public safety, and academic computer networks. Although in general, radio transmitters are not currently permitted in secured areas at Sandia, wireless communications would open new opportunities, allowing mobile and pervasive user access. Without wireless communications, we must live in a ''non-mainstream'' world of fixed, wired networks, where it becomes ever more difficult to attract and retain the best professionals. This report provides a review of the current state of wireless communications, which direction wireless technology is heading, and where wireless technology could be employed at Sandia. A list of recommendations on harnessing the power of wireless communications is provided to aid in building a state-of-the-art communication environment for the 21st century at Sandia.
In 1993, the Government Performance and Results Act (GPRA, PL 103-62) was enacted. GPRA, which applies to all federal programs, has three components: strategic plans, annual performance plans, and metrics to show how well annual plans are being followed. As part of meeting the GRPA requirement in FY2002, a 15-member external review committee chaired by Dr. Alvin Trivelpiece (the Trivelpiece Committee) was convened by Sandia National Laboratories (SNL) on May 7-9, 2002 to review Sandia National Laboratories' Pulsed Power Programs as a component of the Performance Appraisal Process negotiated with the National Nuclear Security Administration of the Department of Energy (NNSA/DOE). The scope of the review included activities in high energy density physics (HEDP), inertial confinement fusion (ICF), radiation/weapon physics, the petawatt laser initiative (PW) and fast ignition, equation-of-state studies, radiation effects science and lethality, x-ray radiography, ZR development, basic research and pulsed power technology research and development, as well as electromagnetics and work for others. In his charge to the Committee, Dr. Jeffrey P. Quintenz, Director of Pulsed Power Sciences (Org. 1600) asked that the evaluation and feedback be based on three criteria: (1) quality of technical activities in science, technology, and engineering, (2) programmatic performance, management, and planning, and (3) relevance to national needs and agency missions. In addition, the director posed specific programmatic questions. The accompanying report, produced as a SAND document, is the report of the Committee's finding.
In high consequence systems, all layers of the protocol stack need security features. If network and data-link layer control messages are not secured, a network may be open to adversarial manipulation. The open nature of the wireless channel makes mobile wireless mobile ad hoc networks (MANETs) especially vulnerable to control plane manipulation. The objective of this research is to investigate MANET performance issues when cryptographic processing delays are applied at the data-link layer. The results of analysis are combined with modeling and simulation experiments to show that network performance in MANETs is highly sensitive to the cryptographic overhead.
The Green Zia Environmental Excellence Program is a voluntary program designed to support and assist New Mexico businesses to achieve environmental excellence through the development of an environmental management system (EMS). Since 2000, organizations within Sandia National Laboratories (SNL) have participated in the program. SNL's Pollution Prevention (P2) program supports and assists SNL organizations by utilizing Green Zia tools to aid in the implementation of each organization's EMS. This report is based on a feedback session held in September 2002 with past SNL Green Zia Program participants. The goal of the feedback session and of this report is to enhance the services that the P2 Program provides to SNL organizations. This report summarizes the feedback received.