Publications

A new viscoplastic theory for CusilABA and other braze alloys has been developed. Like previous viscoplastic theories,this new theory uses a hyperbolic sine function of effective stress in its kinetic equation for the inelastic strain rate. This new theory has an internal state variable which accounts for isotropic hardening and recovery and a second-order, internal state tensor which accounts for kinematic hardening and recovery. Unlike previous theories, the new theory uses evolution equations for the state variables which describe competing mechanisms of power law hardening and static recovery. The evolution equations used in previous theories describe competing mechanisms of linear hardening, dynamic and static recovery. The new viscoplastic theory was implemented in several finite element codes and used in several metal-to-ceramic brazing simulations. Two approaches for obtaining material parameters for the new viscoplastic theory were developed.

A simplified surface reaction mechanism is presented for the CVD of diamond thin films. The mechanism also accounts for formation of point defects in the diamond lattice, an alternate, undesirable reaction pathway. Both methyl radicals and atomic C are considered as growth precursors. While not rigorous in all details, the mechanism is useful in describing the CVD diamond process over a wide range of reaction conditions. It should find utility in reactor modeling studies, for example in optimizing diamond growth rate while minimizing defect formation. This report also presents a simple model relating the diamond point-defect density to the thermal conductivity of the material.

In US DOE, changing circumstances are affecting the management and disposal of solid, low-level radioactive waste (LLW). From 1977 to 1991, the nuclear power industry achieved major reductions in solid waste disposal, and DOE is interested in applying those practices to reduce solid waste at DOE facilities. Project focus was to identify and document commercial nuclear industry best practices for radiological control programs supporting routine operations, outages, and decontamination and decommissioning activities. The project team (DOE facility and nuclear power industry representatives) defined a Work Control Process Model, collected nuclear power industry Best Practices, and made recommendations to minimize LLW at DOE facilities.

This report discusses work performed under a Cooperative Research And Development Agreement (CRADA) with Corning, Inc., to analyze and test various techniques for controlling the motion of a high speed robotic arm carrying an open container of viscous liquid, in this case, molten glass. A computer model was generated to estimate the modes of oscillation of the liquid based on the shape of the container and the viscosity of the liquid. This fluid model was experimentally verified and tuned based on experimental data from a capacitive sensor on the side of the container. A model of the robot dynamics was also developed and verified through experimental tests on a Fanuc S-800 robot arm. These two models were used to estimate the overall modes of oscillation of an open container of liquid being carried by a robot arm. Using the estimated modes, inverse dynamic control techniques were used to determine a motion profile which would eliminate waves on the liquid`s surface. Experimental tests showed that residual surface waves in an open container of water at the end of motion were reduced by over 95% and that in-motion surface waves were reduced by over 75%.

Gas-phase processing plays an important role in the commercial production of a number of ceramic powders. These include titanium dioxide, carbon black, zinc oxide, and silicon dioxide. The total annual output of these materials is on the order of 2 million tons. The physical processes involved in gas-phase synthesis are typical of those involved in solution -phase synthesis: chemical reaction kinetics, mass transfer, nucleation, coagulation, and condensation. This report focuses on the work done under a Laboratory-Directed Research and Development (LDRD) project that explored the use of various high pressure techniques for ceramic powder synthesis. Under this project, two approaches were taken. First, a continuous flow, high pressure water reactor was built and studied for powder synthesis. And second, a supercritical carbon dioxide static reactor, which was used in conjunction with surfactants, was built and used to generate oxide powders.

This guide contains basic information needed to produce a SAND report. Its guidelines reflect DOE regulation and Sandia policy. The guide includes basic writing instructions in an annotated sample report; guidance for organization, format, and layout of reports produced by line organizations; and information about conference papers, journal articles, and brochures. The appendixes contain sections on Sandia`s preferred usage, equations, references, copyrights and permissions, and publishing terms.

Results of a joint Sandia National Laboratories, University of New Mexico, and New Mexico Engineering Research Institute project to investigate an architecture implementing real-time monitoring and tracking technologies in the railroad industry is presented. The work, supported by the New Mexico State Transportation Authority, examines a family of smart sensor products that can be tailored to the specific needs of the user. The concept uses a strap-on sensor package, designed as a value-added component, integrated into existing industry systems and standards. Advances in sensor microelectronics and digital signal processing permit us to produce a class of smart sensors that interpret raw data and transmit inferred information. As applied to freight trains, the sensors` primary purpose is to minimize operating costs by decreasing losses due to theft, and by reducing the number, severity, and consequence of hazardous materials incidents. The system would be capable of numerous activities including: monitoring cargo integrity, controlling system braking and vehicle acceleration, recognizing component failure conditions, and logging sensor data. A cost-benefit analysis examines the loss of revenue resulting from theft, hazardous materials incidents, and accidents. Customer survey data are combined with the cost benefit analysis and used to guide the product requirements definition for a series of specific applications. A common electrical architecture is developed to support the product line and permit rapid product realization. Results of a concept validation, which used commercial hardware and was conducted on a revenue-generating train, are also reported.

SARS is a data acquisition system designed to gather and process radar data from aircraft flights. A database of flight trajectories has been developed for Albuquerque, NM, and Amarillo, TX. The data is used for safety analysis and risk assessment reports. To support this database effort, Sandia developed a collection of hardware and software tools to collect and post process the aircraft radar data. This document describes the data reduction tools which comprise the SARS, and maintenance procedures for the hardware and software system.

Brief articles in this issue are entitled: New testing techniques, textiles on the information superhighway, and knowledge preservation; Structural health monitoring techniques and robust analysis tools assess aging and damaged structures; Sandia`s VCSELs (Vertical-Cavity Surface-Emitting Lasers): sparking a laser diode revolution; Fiber-optic instrumentation trims weeks off the wait for cervical cancer test results; DAMA (Demand Activated Manufacturing Architecture) project boosts competitiveness of US textile industry; SEAMIST (Science and Engineering Associates Membrane Instrumentation and Sampling Technique) cuts contamination cleanup costs; RePAVing the roads to the past (Relevant Point of Access Video); and Sandia receives DOE basic energy sciences award for sol-gel achievements.

A workshop was held on April 12 and 13, 1996, to provide a forum for gathering information pertinent to using the information highway (the Internet and the World Wide Web) for materials and processes (M&P) research. The workshop`s objectives were to identify the priority needs of materials and processes researchers that could be addressed through the Internet, to describe the relevant capabilities of the information highway, to review existing applications of the highway in materials research and related fields for lessons learned, and to identify potential opportunities and key issues. The workshop was planned and organized by the Committee on Materials and Processes Research and the Information Highway, which was established by the National Materials Advisory Board (NMAB) of the National Research Council (NRC). The workshop was requested and sponsored by the Defense Reliance Technology Panel for Advanced Materials.

This paper describes a poster presentation on the capabilities of the VNIITF to produce solid oxide fuel cells. Research areas, personnel, technology, and test facilities are described.

Rigid polyurethane foams are used for supports and as encapsulants for electronic assemblies in almost all weapon systems. Mechanical properties (storage, loss, rubbery, and glassy moduli) of three foams are being evaluated; the test scheme is illustrated. Aging tests are also being run on the long-term performance of foams being used in the Russian Fissile Material Container; there was no significant change in the glass transition temperature, glassy modulus, or rubbery modulus after one year of aging.

Heliostat installation and alignment costs will be an important element in future solar power tower projects. The predicted annual performances of on- and-off axis strategies are compared for 95 m{sup 2} flat-glass heliostats and an external, molten-salt receiver. Actual approaches to heliostat alignment that have been used in the past are briefly discussed, and relative strengths and limitations are noted. The optimal approach can vary with the application.

The framework is versatile and the generalized approach has worked well for a suite of evaluations or as a foundation for evaluation tools including developing the SEDSS computer software system for evaluating site safety for EPA Superfund problems, NRC Low-Level Nuclear Waste facility siting, and UMTRA site remediation decisions; iteration through the performance assessment of the Greater Confinement Disposal Facility; and optimizing data collection for DNAPL problems. In particular, the SEDSS computer system makes a portion of these tools accessible for broad scale application. Development of both details of the process and computer tools to support individual steps continues.

Aim of this laboratory-directed research and development (LDRD) project was to develop diamond and/or diamond-like carbon (DLC) films for electronic applications. Quality of diamond and DLC films grown by chemical vapor deposition (CVD) is not adequate for electronic applications. Nucleation of diamond grains during growth typically results in coarse films that must be very thick in order to be physically continuous. DLC films grown by CVD are heavily hydrogenated and are stable to temperatures {le} 400{degrees}C. However, diamond and DLC`s exceptional electronic properties make them candidates for integration into a variety of microelectronic structures. This work studied new techniques for the growth of both materials. Template layers have been developed for the growth of CVD diamond films resulting in a significantly higher nucleation density on unscratched or unprepared Si surfaces. Hydrogen-free DLC with temperature stability {le} 800{degrees}C has been developed using energetic growth methods such as high-energy pulsed-laser deposition. Applications with the largest system impact include electron-emitting materials for flat-panel displays, dielectrics for interconnects, diffusion barriers, encapsulants, and nonvolatile memories, and tribological coatings that reduce wear and friction in integrated micro-electro-mechanical devices.

The Radiological Environment Modeling System (REMS) quantifies dose to humans working in radiological environments using the IGRIP (Interactive Graphical Robot Instruction Program) and Deneb/ERGO simulation software. These commercially available products are augmented with custom C code to provide radiation exposure information to, and collect radiation dose information from, workcell simulations. Through the use of any radiation transport code or measured data, a radiation exposure input database may be formulated. User-specified IGRIP simulations utilize these databases to compute and accumulate dose to programmable human models operating around radiation sources. Timing, distances, shielding, and human activity may be modeled accurately in the simulations. The accumulated dose is recorded in output files, and the user is able to process and view this output. The entire REMS capability can be operated from a single graphical user interface.

RADTRAN is a computer code for estimating the risks and consequences as transport of radioactive materials (RAM). RADTRAN was developed and is maintained by Sandia National Laboratories for the US Department of Energy (DOE). For incident-free transportation, the dose to persons exposed while the shipment is stopped is frequently a major percentage of the overall dose. This dose is referred to as Stop Dose and is calculated by the Stop Model. Because stop dose is a significant portion of the overall dose associated with RAM transport, the values used as input for the Stop Model are important. Therefore, an investigation of typical values for RADTRAN Stop Parameters for truck stops was performed. The resulting data from these investigations were analyzed to provide mean values, standard deviations, and histograms. Hence, the mean values can be used when an analyst does not have a basis for selecting other input values for the Stop Model. In addition, the histograms and their characteristics can be used to guide statistical sampling techniques to measure sensitivity of the RADTRAN calculated Stop Dose to the uncertainties in the stop model input parameters. This paper discusses the details and presents the results of the investigation of stop model input parameters at truck stops.

The Transportation Technology Department of Sandia National Laboratories develops analytical and computational tools for the US Department of Energy to assess the radiological consequences and risks from the transportation of radioactive materials by all modes. When large quantities of materials are to be transported movements may occur over an extended period of time in what is collectively referred as a ``shipping campaign``. Since the routes over which the shipments occur often remain the same, cumulative exposure to individuals inhabiting the population zones adjacent to the transport links must be estimated. However, individuals do not remain in the same residences throughout their lifetimes and, in fact, move quite often. To appropriately allocate exposures among populations over extended periods of time, perhaps years, requires a model that accounts for three population categories; (1) the original populations residing in the areas adjacent to the transport links, (2) individuals moving out and (3) individuals moving into residences in the designated areas. The model described here accounts for these conditions and will be incorporated as a user option in the RADTRAN computer code for transportation consequence and risk analysis (Reference 1). RADTRAN is a computer code for estimating the consequences and risks associated with the transport of radioactive materials.

This paper discusses a new approach to the development of engineering education materials. The ``Electronic Textbook`` represents the logical progression of the printed textbook in the Electronic Age. The concept behind this approach is simple; to place all of the information contained in a textbook in electronic form. Currently, paper texts exist on the market with electronic supplements, however, this Electronic Textbook would include supplements fully integrated in the whole text. The computer hardware and software needed to make this advance possible have existed for nearly ten years, and they have been readily available to engineering educators and students for over three years. Computer based ``tools`` in engineering textbooks as are prevalent today range from computer styled algorithms and code snippets, to fully developed software applications with graphical user interfaces on floppy disks attached to the back covers of books. The next logical step in publishing is to dispense with the paper book entirely, by distributing textbooks via electronic media such as CD-ROM. Electronic Textbooks use the full range of multi-media technologies in the learning and teaching process including video clips, computer animations and fully functional numerical engines as integral parts of the textbook material. This is very appealing since interactive media provide teaching tools that appeal to divergent learning styles. The advantages of Electronic Textbooks lead to several challenges. Special attention must be paid to the development of user interfaces; navigation is of particular importance when non- linear exploration is encouraged. These issues are being addressed at the Sandia National Laboratories by an electronic documentation development team. This team includes experts in engineering, in human factors, and in computer hardware and software development. Guidelines for the development of electronic textbooks based on the experiences of this team are provided.

A range-to-target algorithm for application to targets which exhibit a crude hyperbolic wiggle trace is described. The current practice is to use the apex time of the hyperbolic response together with an estimate of the propagation velocity to furnish the range. This new algorithm minimizes a difference function over a velocity search interval to provide the range. Examples for a variety of media, targets, range, and operating frequency are given for both simulated data and actual field data provided by others. Generally, the range is within 5% of the true value when known, or is consistent with values furnished by others.

A new class of inorganic ion exchangers called crystalline silicotitanates (CST), invented by researchers at Sandia National Laboratories and Texas A&M University, has been commercialized in a joint Sandia-UOP effort. The original developmental materials exhibited high selectivity for the ion exchange of cesium, strontium, and several other radionuclides from highly alkaline solutions containing molar concentrations of Na{sup +}. The materials also showed excellent chemical and radiation stability. Together, the high selectivity and stability of the CSTs made them excellent candidates for treatment of solutions such as the Hanford tank supernates and other DOE radwastes. Sandia National Laboratories and UOP have teamed under a Cooperative Research and Development Agreement (CRADA) to develop CSTs in the powdered form and in an engineered form suitable for column ion exchange use. A continuous-flow, column ion exchange process is expected to be used to remove Cs and other radionuclides from the Hanford supernatant. The powder material invented by the Sandia and Texas A&M team consists of submicron-size particles. It is not designed for column ion exchange but may be used in other applications.

In finite-element, transient dynamics simulations, physical objects are typically modeled as Lagrangian meshes because the meshes can move and deform with the objects as they undergo stress. In many simulations, such as computations of impacts or explosions, portions of the deforming mesh come in contact with each other as the simulation progresses. These contacts must be detected and the forces they impart to the mesh must be computed at each timestep to accurately capture the physics of interest. While the finite-element portion of these computations is readily parallelized, the contact detection problem is difficult to implement efficiently on parallel computers and has been a bottleneck to achieving high performance on large parallel machines. In this paper we describe a new parallel algorithm for detecting contacts. Our approach differs from previous work in that we use two different parallel decompositions, a static one for the finite element analysis and dynamic one for contact detection. We present results for this algorithm in a parallel version of the transient dynamics code PRONTO-3D running on a large Intel Paragon.

This study has demonstrated the feasibility of TiO{sub 2} photocatalysis to treat EDTA and several metal-EDTA complexes that can be found in industrial wastewaters. For the EDTA complexes of metals capable of photodeposition, such as Cu and Pb, certain reaction conditions were shown to facilitate the simultaneous complex degradation and photodeposition of these metals onto the catalyst. With metals that do not easily photodeposit, such as Ni and Cd, it is shown that the complex degradation is still facilitated, and can enhance other metals removal processes after photocatalytic treatment. Because the treatment of these metal-EDTA complexes typically requires special measures, there may exist situations where TiO{sub 2} photocatalysis could actually be the preferred method of treatment. However, its use should be compared economically to other more established advanced oxidation technologies. This necessity is demonstrated in the economic comparison to ozone treatment for EDTA degradation alone, where ozone treatment appears to be the clear choice in this application.

Short communication.

Problems in environmental restoration that involve detecting or monitoring contamination or site characterization often benefit from procedures that help select sampling or drilling locations for obtaining meaningful data that support the analysis. One example of this type of procedure is a spatial sampling program that will ``automatically`` (based on the implementation of a computer algorithm) guide an iterative investigation through the process of site characterization at a minimal cost to determine appropriate remediation activities. In order to be effective, such a procedure should translate site and modeling uncertainties into terms that facilitate comparison with regulations and should also provide a methodology that will lead to an efficient sampling plan over the course of the analysis. In this paper, a general framework is given that can accomplish these objectives and can be applied to a wide range of environmental restoration applications. The methodology is illustrated using an example where soil samples support the characterization of a chemical waste landfill area.

Etch rates up to 7000{angstrom}/min for InP and 3500{angstrom}/min for GaAs are obtained for high microwave power (1000W) CH{sub 4}/H{sub 2}/Ar Electron Cyclotron Resonance plasma etching. Preferential loss of the group V element leads to nonstoichiometric, unacceptably rough surfaces on In-based binary semiconductors at microwave powers {ge}400W, regardless of plasma composition. Both Ga- and Al-based materials retain smooth, stoichiometric surfaces even at I000W, but the rates are still much slower than for C1{sub 2} plasma chemistries. The results suggest that CH{sub 4}/H{sub 2} plasmas are not well suited to ECR systems operating at high powers.

Structural system simulation is important in analysis, design, testing, control, and other areas, but it is particularly difficult when the system under consideration is nonlinear. Artificial neural networks offer a useful tool for the modeling of nonlinear systems, however, such modeling may be inefficient or insufficiently accurate when the system under consideration is complex. This paper shows that there are several transformations that can be used to uncouple and simplify the components of motion of a complex nonlinear system, thereby making its modeling and simulation a much simpler problem. A numerical example is also presented.

Short communication.

The Geothermal Drilling Organization (GDO), formed in the early 1980s by the geothermal industry and the U.S. Department of Energy (DOE) Geothermal Division, sponsors specific development projects to advance the technologies used in geothermal exploration, drilling, and production phases. Individual GDO member companies can choose to participate in specific projects that are most beneficial to their industry segment. Sandia National Laboratories is the technical interface and contracting office for the DOE in these projects. Typical projects sponsored in the past have included a high temperature borehole televiewer, drill bits, muds/polymers, rotary head seals, and this project for drill pipe protectors. This report documents the development work of Regal International for high temperature geothermal pipe protectors.

Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays, driven by 5 MA from the Saturn accelerator, are measured and compared with LLNL Radiation-Hydro-Code (RHC) and SNL Hydro-Code (HC) numerical models. Multiple implosions, due to sequential compressions and expansions of the plasma, are inferred from the measured multiple x-radiation bursts. Timing of the multiple implosions and the thermal x-ray spectra measured between 1 and 10 keV are consistent with the RHC simulations. The magnitude of the nonthermal x-ray emission measured from 10 to 100 keV ranges from 0.02 to 0.08% of the total energy radiated and is correlated with bright-spot emission along the z-axis, as observed in earlier Gamble-11 single exploding-wire experiments. The similarities of the measured nonthermal spectrum and bright-spot emission with those measured at 0.8 MA on Gamble-II suggest a common production mechanism for this process. A model of electron acceleration across magnetic fields in highly-collisional, high-atomic-number plasmas is developed, which shows the existence of a critical electric field, E{sub c}, below which strong nonthermal electron creation (and the associated nonthermal x rays) do not occur. HC simulations show that significant nonthermal electrons are not expected in this experiment (as observed) because the calculated electric fields are at least one to two orders-of-magnitude below E{sub c}. These negative nonthermal results are confirmed by RHC simulations using a nonthermal model based on a Fokker-Plank analysis. Lastly, the lower production efficiency and the larger, more irregular pinch spots formed in this experiment relative to those measured on Gamble II suggest that implosion geometries are not as efficient as single exploding-wire geometries for warm x-ray production.

This is the summary report for the Protocol Extensions for Asynchronous Transfer Mode project, funded under Sandia`s Laboratory Directed Research and Development program. During this one-year effort, techniques were examined for integrating security enhancements within standard ATM protocols, and mechanisms were developed to validate these techniques and to provide a basic set of ATM security assurances. Based on our experience during this project, recommendations were presented to the ATM Forum (a world-wide consortium of ATM product developers, service providers, and users) to assist with the development of security-related enhancements to their ATM specifications. As a result of this project, Sandia has taken a leading role in the formation of the ATM Forum`s Security Working Group, and has gained valuable alliances and leading-edge experience with emerging ATM security technologies and protocols.

An investigation of the shock compression properties of high-strength ceramics has been performed using controlled planar impact techniques. In a typical experimental configuration, a ceramic target disc is held stationary, and it is struck by plates of either a similar ceramic or by plates of a well-characterized metal. All tests were performed using either a single-stage propellant gun or a two-stage light-gas gun. Particle velocity histories were measured with laser velocity interferometry (VISAR) at the interface between the back of the target ceramic and a calibrated VISAR window material. Peak impact stresses achieved in these experiments range from about 3 to 70 GPa. Ceramics tested under shock impact loading include: Al{sub 2}O{sub 3}, AlN, B{sub 4}C, SiC, Si{sub 3}N{sub 4}, TiB{sub 2}, WC and ZrO{sub 2}. This report compiles the VISAR wave profiles and experimental impact parameters within a database-useful for response model development, computational model validation studies, and independent assessment of the physics of dynamic deformation on high-strength, brittle solids.

This study provides a scoping safety assessment for disposal of toxic metals contained in Department of Energy (DOE) mixed low-level waste (MLLW) at six DOE sites that currently have low-level waste (LLW) disposal facilities--Savannah River Site, Oak Ridge Reservation, Los Alamos National Laboratory, Hanford Reservation, Nevada Test Site, and Idaho National Engineering Laboratory. The study has focused on the groundwater contaminant pathway, which is considered to be the dominant human exposure pathway from shallow land MLLW disposal. A simple and conservative transport analysis has been performed using site hydrological data to calculate site-specific ``permissible`` concentrations of toxic metals in grout-immobilized waste. These concentrations are calculated such that, when toxic metals are leached from the disposal facility by infiltrating water and attenuated in local ground-water system the toxic metal concentrations in groundwater below the disposal facility do not exceed the Maximum Contaminant Levels as stated in the National Primary Drinking Water Regulation. The analysis shows that and sites allow about I00 times higher toxic metal concentrations in stabilized waste leachate than humid sites. From the limited available data on toxic metal concentrations in DOE MLLW, a margin of protection appears to exist in most cases when stabilized wastes containing toxic metals are disposed of at the DOE sites under analysis. Possible exceptions to this conclusion are arsenic, chromium selenium, and mercury when disposed of at some humid sites such as the Oak Ridge Reservation. This analysis also demonstrates that the US Environmental Protection Agency`s prescriptive regulatory approach that defines rigid waste treatment standards does not inherently account for the variety of disposal environments encountered nationwide and may result in either underprotection of groundwater resources (at humid sites) or an excessive margin of protection (at and sites).

A brief overview is given for two software developments related to the ITS code system. These developments provide parallel processing and visualization capabilities and thus allow users to perform ITS calculations more efficiently. Timing results and a graphical example are presented to demonstrate these capabilities.

The ability to rapidly command multi-robot behavior is crucial for the acceptance and effective utilization of multiple robot control. To achieve this, a modular- multiple robot control solution is being, pursued using the SMART modular control architecture. This paper investigates the development of a new dual-arm kinematics module (DUAL-KLN) which allows multiple robots, previously controlled as separate stand-alone systems, to be controlled as a coordinated multi-robot system. The DUAL-KIN module maps velocity and force information from a center point of interest on a grasped object to the tool centers of each grasping robot. Three-port network equations are used and mapped into the scattering operator domain in a computationally efficient form. Application examples of the DUAL-KLN module in multi-robot coordinated control are given.

This paper analyses the problems and presents solutions for building a modular robot control system. The approach requires modeling the entire robot system using multi-dimensional passive networks, breaking the system into subnetwork ``modules,`` and then discretizing the subnetworks, or n-ports, in a passivity preserving fashion. The main difficulty is the existence of ``algebraic loops`` in the discretized system. This problem is overcome by the use of scattering theory, whereby the inputs and outputs of the n-ports are mapped into wave variables before being discretized. By first segmenting the n-ports into nonlinear memoryless subnetworks and linear dynamic subnetworks and then discretizing using passivity preserving techniques such as Tustin`s method, a complete modular robot control solution is obtained.

The characteristics of a piezoresistive accelerometer in shock environments are being studied at Sandia National Laboratories in the Mechanical Shock Testing Laboratory. A Hopkinson bar capability has been developed to extend our understanding of the piezoresistive accelerometer, in two mechanical configurations, in the high frequency, high shock environments where measurements are being made. In this paper, the beryllium Hopkinson bar configuration with a laser doppler vibrometer as the reference measurement is described. The in-axis performance of the piezoresistive accelerometer for frequencies of dc-50 kHz and shock magnitudes of up to 70,000 g as determined from measurements with a beryllium Hopkinson bar are presented. Preliminary results of characterizations of the accelerometers subjected to cross-axis shocks in a split beryllium Hopkinson bar configuration are presented.

An advanced packaging concept has been developed for optical devices. This concept allows multiple fibers to be coupled to photonic integrated circuits, with no fiber penetration of the package walls. The principles used to accomplish this concept involves a second-order grating to couple light in or out of the photonic circuit, and a binary optic lens which receives this light and focuses it into a single-mode optical fiber. Design, fabrication and electrical/optical measurements of this packaging concept are described.

An Advanced Fork System has been designed to add gamma-ray collimation and spectroscopy capability to the Fork measurement system, which has been used for burnup verification at pressurized water reactors (PWR). The Advanced Fork System measures the neutron and gamma-ray yields and the energy spectnum of gamma-rays from spent fuel assemblies. A cadmium-zinc-telluride (CZT) crystal permits the identification of the radioactive isotopes of cesium (134 and 137). The cesium isotope concentrations, with proper calibration can be used to determine the assembly burnup independent of reactor records, and to provide a measure of minimum cooling time. Tungsten gamma-ray collimators are used to define the spatial resolution of the gamma-ray detectors along the axis of the assembly. The capability to rapidly perform a burnup distribution scan using the collimated ion chamber may be important to the verification of burnup for boiling water reactors (BWR).

An open-loop control method is presented for reducing the oscillatory motion of rotary crane payloads during operator commanded maneuvers. A typical rotary crane consists of a multiple degree-of-freedom platform for positioning a spherical pendulum with an attached payload. The crane operator positions the Payload by issuing a combination of translational and rotational commands to the platform as well as load-line length changes. Frequently, these pendulum modes are time-varying and exhibit low natural frequencies. Maneuvers are therefore performed at rates sufficiently slow so as not to excite oscillation. The strategy presented here generates crane commands which suppress vibration of the payload without a priori knowledge of the desired maneuver. Results are presented for operator in-the-loop positioning using a real-time dynamics simulation of a three-axis rotary crane where the residual sway magnitude is reduced in excess of 4OdB.

A real-time method is presented to adoptively estimate three-dimensional unmodeled external torques acting on a spacecraft. This is accomplished by forcing the tracking error dynamics to follow the Lyapunov function underlying the feedback control law. For the case where the external torque is constant, the tracking error dynamics are shown to converge asypmtotically. The methodology applies not only to the control law used in this paper, but can also be applied to most Lyapunov derived feedback control laws. The adaptive external torque estimation is very robust in the presence of measurement noise, since a numerical integration is used instead of a numerical differentiation. Spacecraft modeling errors, such as in the inertia matrix, are also compensated for by this method. Several examples illustrate the practical significance of these ideas.

It is often desirable to separate particles from a particle-laden fluid stream. This is typically accomplished by passing the stream through a filter, an impactor, or a cyclone. In each of these devices, particles encounter obstacles in the flow path (i.e. filter material, the impaction surface, the cyclone side wall). However, in some applications, it is desirable to prevent particles from impinging on solid surfaces. For example, particle interaction with a solid surface may contaminate the surface, modify the particles via mechanical or chemical processes, or adversely affect the surface via material modification or heat transfer. In such situations, it is still possible to separate particles from the particle-laden flow stream by transferring them to another adjacent flow stream. This transfer of particles from one flow stream to another is termed nonimpact particle separation. One type of device that separates particles from a flow stream by nonimpact particle separation is the anticyclone. In contradistinction to a cyclone, the particle-laden flow is deflected from its original direction by a wall that curves away from the original flow direction, rather than into it. The computational fluid dynamics code FIDAP (Fluid Dynamics International) is used to perform two-dimensional fluid-flow and particle-motion calculations for a representative device geometry. These calculations indicate that the anticyclone geometry examined accomplishes nonimpact particle separation, as expected. Flow patterns and overall particle-separation characteristics are found to be fairly insensitive to Reynolds number for values above 100 regardless of whether the flow is laminar or turbulent. An approximate analytical relation describing anticyclone nonimpact particle separation is developed and validated by comparison to the numerical simulations. The additional information required to design useful devices employing nonimpact particle separation is outlined.

This report has demonstrated techniques that can be used to construct solutions to the 3-D electromagnetic inverse problem using full wave equation modeling. To this point great progress has been made in developing an inverse solution using the method of conjugate gradients which employs a 3-D finite difference solver to construct model sensitivities and predicted data. The forward modeling code has been developed to incorporate absorbing boundary conditions for high frequency solutions (radar), as well as complex electrical properties, including electrical conductivity, dielectric permittivity and magnetic permeability. In addition both forward and inverse codes have been ported to a massively parallel computer architecture which allows for more realistic solutions that can be achieved with serial machines. While the inversion code has been demonstrated on field data collected at the Richmond field site, techniques for appraising the quality of the reconstructions still need to be developed. Here it is suggested that rather than employing direct matrix inversion to construct the model covariance matrix which would be impossible because of the size of the problem, one can linearize about the 3-D model achieved in the inverse and use Monte-Carlo simulations to construct it. Using these appraisal and construction tools, it is now necessary to demonstrate 3-D inversion for a variety of EM data sets that span the frequency range from induction sounding to radar: below 100 kHz to 100 MHz. Appraised 3-D images of the earth`s electrical properties can provide researchers opportunities to infer the flow paths, flow rates and perhaps the chemistry of fluids in geologic mediums. It also offers a means to study the frequency dependence behavior of the properties in situ. This is of significant relevance to the Department of Energy, paramount to characterizing and monitoring of environmental waste sites and oil and gas exploration.

In the stereolithography process, three dimensional parts are built layer by layer using a laser to selectively cure slices of a photocurable resin, one on top of another. As the laser spot passes over the surface of the resin, the ensuing chemical reaction causes the resin to shrink and stiffen during solidification. When laser paths cross or when new layers are cured on top of existing layers, residual stresses are generated as the cure shrinkage of the freshly gelled resin is constrained by the adjoining previously-cured material. These internal stresses can cause curling in the compliant material. A capability for performing finite element analyses of the stereolithography process has been developed. Although no attempt has been made to incorporate all the physics of the process, a numerical platform suitable for such development has been established. A methodology and code architecture have been structured to allow finite elements to be birthed (activated) according to a prescribed order mimicking the procedure by which a laser is used to cure and build-up surface layers of resin to construct a three dimensional geometry. In its present form, the finite element code incorporates a simple phenomenological viscoelastic material model of solidification that is based on the shrinkage and relaxation observed following isolated, uncoupled laser exposures. The phenomenological material model has been used to analyze the curl in a simple cantilever beam and to make qualitative distinctions between two contrived build styles.

Sandia National Laboratories, New Mexico, conducts the Utility Battery Storage Systems Program, which is sponsored by the U.S. Department of Energy`s Office of Utility Technologies. The goal of this program is to assist industry in developing cost-effective battery systems as a utility resource option by 2000. Sandia is responsible for the engineering analyses, contracted development, and testing of rechargeable batteries and systems for utility energy storage applications. This report details the technical achievements realized during fiscal year 1995.

This report briefly describes the improvements and corrections made to a seismic network performance modeling code called NetSim. After expanding its supporting database, the modified code was used to predict the detection and location performances of an International Seismic Monitoring System (ISMS) proposed early in 1995 by the Group of Scientific Experts (GSE) supporting the Comprehensive Test Ban Treaty (CTBT) negotiators. The performance estimates indicated that the primary network achieves or exceeds the GSE goal of detecting a fully coupled 1kiloton nuclear shot contained in consolidated rock anywhere on the earth. It was also shown that without calibrated regional location models, the primary network alone cannot achieve the GSE location accuracy requirement of 1000 square kilometers at the detection threshold of the primary network, but with the help of 67 auxiliary stations that goal can be achieved in the northern hemisphere. Once the regional location models become better calibrated, the predictions based on these models indicated that the primary network should be able to realize the GSE requirement throughout much of the world. However, the location accuracy requirement is not realized in Central America, on the oceanic islands, on continental margins in the southern hemisphere, and in Antarctica. The introduction of the 67 auxiliary stations into the calibrated network primarily broadens the regions already having good location accuracies. The location performance estimates may be regarded as conservative since the S-wave arrivals were not included A comprehensive set of scenarios are illustrated in this effort to better understand various influences on network performance.

The end of the cold war has resulted in many changes for the Nuclear Weapons Complex (NWC). We now work in a smaller complex, with reduced resources, a smaller stockpile, and no new phase 3 weapons development programs. This new environment demands that we re-evaluate the way we design and produce nuclear weapons. The Defense Program (DP) Business Practices Re-engineering activity was initiated to improve the design and production efficiency of the DP Sector. The activity had six goals: (1) to identify DP business practices that are exercised by the Product Realization Process (PRP); (2) to determine the impact (positive, negative, or none) of these practices on defined, prioritized customer criteria; (3) to identify business practices that are candidates for elimination or re-engineering; (4) to select two or three business practices for re-engineering; (5) to re-engineer the selected business practices; and (6) to exercise the re-engineered practices on three pilot development projects. Business practices include technical and well as administrative procedures that are exercised by the PRP. A QFD exercise was performed to address (1)-(4). The customer that identified, defined, and prioritized the criteria to rate the business practices was the Block Change Advisory Group. Five criteria were identified: cycle time, flexibility, cost, product performance/quality, and best practices. Forty-nine business practices were identified and rated per the criteria. From this analysis, the group made preliminary recommendations as to which practices would be addressed in the re-engineering activity. Sixteen practices will be addressed in the re-engineering activity. These practices will then be piloted on three projects: (1) the Electronic Component Assembly (ECA)/Radar Project, (2) the B61 Mod 11, and (3) Warhead Protection Program (WPP).

We report measurements of the energies and angular distributions of positive ions in an inductively coupled argon plasma in a GEC reference cell. Use of two separate ion detectors allowed measurement of ion energies and fluxes as a function of position as well as ion angular distributions on the discharge centerline. The inductive drive on our system produced high plasma densities (up to 10{sup 12}/cm{sup 3} electron densities) and relatively stable plasma potentials. As a result, ion energy distributions typically consisted of a single feature well separated from zero energy. Mean ion energy was independent of rf power and varied inversely with pressure, decreasing from 29 eV to 12 eV as pressure increased form 2.4 m Torr to 50 mTorr. Half-widths of the ion angular distributions in these experiments varied from 5 degrees to 12.5 degrees, or equivalently, transverse temperatures varied form 0.2 to 0.5 eV with the distributions broadening as either pressure or RF power were increased.

Slide coating flow is a workhorse process for manufacturing precision film-coating products. Properly starting up a slide coating process is very important in reducing wastage during startup and ensuring that the process operates within the desired `coating window.` A two-phase flow analysis of slide-coating startup was performed by Palmquist and Scriven (1994) using Galerkin`s method with finite-element basis functions and an elliptic mesh generation scheme. As reported by Chen (1992) from flow visualization experiments, a continuously coated liquid film breaks up into rivulets, which are coating stripes with dry lanes in between, when the coated film becomes thinner and thinner due to either the increase in substrate speed or the reduction in pre-metered feed-liquid pump speed. It was observed that the coated-film breakup process originated from the coating bead, thus the name of bead breakup. Understanding the bead-breakup phenomena and elucidating mechanisms involved will provide guidance for manufacturing thinner coating, an industrial trend for better product performance. In this paper we present simulation results of slide-coating flows obtained from a computational method capable of describing arbitrary, three-dimensional and time-dependent deformations. The method, which is available in a commercial code, uses a fixed grid through which fluid interfaces are tracked by a Volume-of-Fluid technique (Hirt and Nichols, 1981). Surface tension, wall adhesion, and viscous stresses are fully accounted for in our analysis. We illustrate our computational approach by application to startup and the bead-breakup problems. As will be shown, for rapid processes our approach offers the computational efficiency and robustness that are difficult o achieve in conventional finite-element-based methods.

We detail a new monolithically integrated silicon mold/surface-micromachining process which makes possible the fabrication of stiff, high-aspect-ratio micromachined structures integrated with finely detailed, compliant structures. An important example, which we use here as our process demonstration vehicle, is that of an accelerometer with a large proof mass and compliant suspension. The proof mass is formed by etching a mold into the silicon substrate, lining the mold with oxide, filling it with mechanical polysilicon, and then planarizing back to the level of the substrate. The resulting molded structure is recessed into the substrate, forming a planar surface ideal for subsequent processing. We then add surface-micromachined springs and sense contacts. The principal advantage of this new monolithically integrated mold/surface-micromachining process is that it decouples the design of the different sections of the device: In the case of a sensitive accelerometer, it allows us to optimize independently the proof mass, which needs to be as large, stiff, and heavy as possible, and the suspension, which needs to be as delicate and compliant as possible. The fact that the high-aspect-ratio section of the device is embedded in the substrate enables the monolithic integration of high-aspect-ratio parts with surface-micromachined mechanical parts, and, in the future, also electronics. We anticipate that such an integrated mold/surface micromachining/electronics process will offer versatile high-aspect-ratio micromachined structures that can be batch-fabricated and monolithically integrated into complex microelectromechanical systems.

Sandia National Laboratories has developed an approach to the design, evaluation, deployment and operation of intelligent systems which is called System Composer. This toolkit provides an infrastructure and architecture for robot and automation system users to readily integrate system components and share mechatronic, sensor, and information resources over networks. The technology described in this paper provides a framework for real-time collaboration between researchers, manufacturing entities, design entities, and others without regard to relative location. An overview of the toolkit including its elements and architecture is provided along with examples of its use.

The Department of Energy (DOE) proposes to construct and operate the National Ignition Facility (NIF) in support of the Stockpile Stewardship and Management (SSM) Programmatic Environmental impact Statement (PEIS). The National Environmental Policy Act requires the DOE to look at alternative sites for the NIF. The SSM PEIS will evaluate four alternative locations for the NIF. This study documents the process and results of a site selection study for a preferred site for the NIF at SNL/NM. The NIF research objectives are to provide the world`s most powerful laser systems to be used in ignition of fusion fuel and energy gain to perform high energy density and radiation effects experiments in support of the DOE`s national security, energy, and basic science research mission. The most immediate application of the NIF will be to provide nuclear-weapon-related physics data, since many phenomena occurring on the laboratory scale are similar to those that occur in weapons. The NIF may also provide an important capability for weapons effects simulation. The NIF is designed to achieve propagating fusion bum and modest energy gain for development as a source of civilian energy.

The Environmental Restoration Project at Sandia National Laboratories, New Mexico is tasked with assessment and remediation of the Mixed Waste Landfill in Technical Area 3. The Mixed Waste Landfill is an inactive, low-level radioactive and mixed waste disposal site. The Mixed Waste Landfill was subject to an extensive surface soil sampling program for tritium in July 1993. Results indicate that surface soils at the landfill contain significant levels of tritium. The classified area of the landfill contains the highest levels of tritium. Results also indicate that tritium has migrated beyond the fenced boundary of the classified area of the landfill.

The Technology Information Environment with Industry (TIE-In{trademark}) provides users with controlled access to distributed laboratory resources that are packaged in intelligent user interfaces. These interfaces help users access resources without requiring the user to have technical or computer expertise. TIE-In utilizes existing, proven technologies such as the Kerberos authentication system, X-Windows, and UNIX sockets. A Front End System (FES) authenticates users and allows them to register for resources and subsequently access them. The FES also stores status and accounting information, and provides an automated method for the resource owners to recover costs from users. The resources available through TIE-In are typically laboratory-developed applications that are used to help design, analyze, and test components in the nation`s nuclear stockpile. Many of these applications can also be used by US companies for non-weapons-related work. TIE-In allows these industry partners to obtain laboratory-developed technical solutions without requiring them to duplicate the technical resources (people, hardware, and software) at Sandia.

Today`s society depends upon many structures (such as aircraft, bridges, wind turbines, offshore platforms, buildings, and nuclear weapons) which are nearing the end of their design lifetime. Since these structures cannot be economically replaced, techniques for structural health monitoring must be developed and implemented. Modal and structural dynamics measurements hold promise for the global non-destructive inspection of a variety of structures since surface measurements of a vibrating structure can provide information about the health of the internal members without costly (or impossible) dismantling of the structure. In order to develop structural health monitoring for application to operational structures, developments in four areas have been undertaken within this project: operational evaluation, diagnostic measurements, information condensation, and damage identification. The developments in each of these four aspects of structural health monitoring have been exercised on a broad range of experimental data. This experimental data has been extracted from structures from several application areas which include aging aircraft, wind energy, aging bridges, offshore structures, structural supports, and mechanical parts. As a result of these advances, Sandia National Laboratories is in a position to perform further advanced development, operational implementation, and technical consulting for a broad class of the nation`s aging infrastructure problems.

Prosperity Games are an outgrowth and adaptation of move/countermove and seminar War Games. Prosperity Games are simulations that explore complex issues in a variety of areas including economics, politics, sociology, environment, education and research. These issues can be examined from a variety of perspectives ranging from a global, macroeconomic and geopolitical viewpoint down to the details of customer/supplier/market interactions in specific industries. All Prosperity Games are unique in that both the game format and the player contributions vary from game to game. This report documents the University Prosperity Game conducted under the sponsorship of the Anderson Schools of Management at the University of New Mexico. This Prosperity Game was initially designed for the roadmap making effort of the National Electronics Manufacturing Initiative (NEMI) of the Electronics Subcommittee of the Civilian Industrial Technology Committee under the aegis of the National Science and Technology Council. The game was modified to support course material in MGT 508, Ethical, Political, and Social Environment of Business. Thirty-five students participated as role players. In this educational context the game`s main objectives were to: (1) introduce and teach global competitiveness and business cultures in an experiential classroom setting; (2) explore ethical, political, and social issues and address them in the context of global markets and competition; and (3) obtain non-government views regarding the technical and non-technical (i.e., policy) issues developed in the NEMI roadmap-making endeavor. The negotiations and agreements made during the game, along with the student journals detailing the players feelings and reactions to the gaming experience, provide valuable insight into the benefits of simulation as an advanced learning tool in higher education.

The EIGER project (Electromagnetic Interactions GenERalized) endeavors to bring the next generation of spectral domain electromagnetic analysis tools to maturity and to cast them in a general form which is amenable to a variety of applications. The tools are written in Fortran 90 and with an object oriented philosophy to yield a package that is easily ported to a variety of platforms, simply maintained, and above all efficiently modified to address wide ranging applications. The modular development style and the choice of Fortran 90 is also driven by the desire to run efficiently on existing high performance computer platforms and to remain flexible for new architectures that are anticipated. The electromagnetic tool box consists of extremely accurate physics models for 2D and 3D electromagnetic scattering, radiation, and penetration problems. The models include surface and volume formulations for conductors and complex materials. In addition, realistic excitations and symmetries are incorporated, as well as, complex environments through the use of Green`s functions.

Enhanced performance goals and environmental restrictions have heightened the consideration for use of alternative solders as replacements for the traditional tin-lead (Sn-Pb) eutectic and near-eutectic alloys. However, the implementation of non-Pb bearing surface finishes may lag behind solder alloy development. A study was performed which examined the effect(s) of Pb contamination on the performance of Sn-Ag-Bi and Sn-Ag-Cu-Sb lead-free solders by the controlled addition of 63Sn-37Pb solder at levels of 0.5 {minus} 8.0 wt.%. Thermal analysis and ring-in-plug shear strength studies were conducted on bulk solder properties. Circuit board prototype studies centered on the performance of 20I/O SOIC gull wing joints. Both alloys exhibited declines in their melting temperatures with greater Sn-Pb additions. The ring-in-plug shear strength of the Sn-Ag-Cu-Sb solder increased slightly with Sn-Pb levels while the Sn-Ag-Bi alloy experienced a strength loss. The mechanical behavior of the SOIC (Small Outline Integrated Circuit) Sn-Ag-Bi solder joints reproduced the strength levels were insensitive to 10,106 thermal cycles. The Sn-Ag-Cu-Sb solder showed a slight decrease in the gull wing joint strengths that was sensitive to the Pb content of the surface finish.

An optical ordnance firing system consisting of a portable hand held solid state rod laser and an optically ignited detonator has been developed for use in explosive ordnance disposal (EOD) activities. Solid state rod laser systems designed to have an output of 150 mJ in a 500 microsecond pulse have been produced and evaluated. A laser ignited detonator containing no primary explosives has been designed and fabricated. The detonator has the same functional output as an electrically fired blasting cap. The optical ordnance firing system has demonstrated the ability to reliably detonate Comp C-4 through 1000 meters of optical fiber.

Although materials understanding and modeling is not currently advanced to the point of failure prediction for most critical areas for stockpile components, research should continue to extend the knowledge base and enable science based choices for future programs or upgrades. Several critical areas are lacking for a science-based lifetime extension of the current stockpile. Hermeticity is critical for many components but modeling and predicative capabilities are limited in these areas. PETN is prevalent throughout the stockpile but modeling and predictive capability for autocatalysis and non-hermetic lifetimes is limited. Corrosion is a frequently observed age-related finding from the historical stockpile but the ability to predict the initiation of corrosion is limited. Advanced electronics are in some current weapons types and will most likely be a part of any retrofits and upgrades in the future. Understanding of stress voiding and electromigration in microelectronics is limited and predictions are not yet available. Polymeric materials are prevalent throughout the stockpile and temperature dependent response mass transport properties are not well understood. Modeling and predictive capabilities for polymeric materials are limited.

Models of the performance of primary Li/SOCl{sub 2} cells can provide for realistic comparisons between technical information from different sources, and set standards that electronic circuit designers may refer to in the generation of high-quality products. Data from various investigators were used to derive mathematical- statistical relationships with physical design features (e.g. size and materials), operating parameters (e.g. current and temperature) and storage conditions (time and temperature). These efforts were substantially promoted by normalization procedures. For example, current loads were converted into current densities, or if appropriate, into current per unit cathode volume. Similarly, cell capacities were standardized with the maximum values observed at low current and also with respect to the cathode volume. Particular emphasis was placed on evaluations of voltage-delay, cell capacity and self-discharge, for which several equations were established. In spite of a considerable expenditure in time to find high-quality datasets, the reality is that all of the reviewed studies are flawed in one way or another. Specifically, all datasets are afflicted with sizable experimental errors and the precision of the regression equations is much lower than is deemed necessary for a universal model of the lithium thionyl chloride cell. Each of the equations has some definite truth content, but is generally incapable of bridging the gap between different studies. The basic failure to come up with a unifying model for Li/SOCl{sub 2} batteries leaves only one benefit of the present analysis, namely to provide guidance for future investigations. Several recommendations are made based on the insight gained during the search for good data in the relevant literature.

The HALFTON experiment explored the phenomena of high explosive detonations in 90% water-saturated tuff rock. The explosive source was a 453 kg TNT sphere which was grouted in a drift in G Tunnel, Nevada Test Site. Active gages measured stresses and motions in the range of 1.3 to 5.3 cavity radii and showed a peak stress decay as range raised to the {minus}2.77 power. Additional stress gages were fielded to investigate the gage inclusion problem.

Fast, accurate imaging of complex, oil-bearing geologies, such as overthrusts and salt domes, is the key to reducing the costs of domestic oil and gas exploration. Geophysicists say that the known oil reserves in the Gulf of Mexico could be significantly increased if accurate seismic imaging beneath salt domes was possible. A range of techniques exist for imaging these regions, but the highly accurate techniques involve the solution of the wave equation and are characterized by large data sets and large computational demands. Massively parallel computers can provide the computational power for these highly accurate imaging techniques. A brief introduction to seismic processing will be presented, and the implementation of a seismic-imaging code for distributed memory computers will be discussed. The portable code, Salvo, performs a wave equation-based, 3-D, prestack, depth imaging and currently runs on the Intel Paragon and the Cray T3D. It used MPI for portability, and has sustained 22 Mflops/sec/proc (compiled FORTRAN) on the Intel Paragon.

A new solderability test method has been developed at Sandia National Laboratories that simulates the capillary flow physics of solders on circuit board surfaces. The solderability test geometry was incorporated on a circuit board prototype that was developed for a National Center for Manufacturing Sciences (NCMS) program. The work was conducted under a cooperative research and development agreement between Sandia National Laboratories, NCMS, and several PWB fabricators (AT&T, IBM, Texas Instruments, United Technologies/Hamilton Standard and Hughes Aircraft) to advance PWB interconnect technology. The test was used to investigate the effects of environmental prestressing on the solderability of printed wiring board (PWB) copper finishes. Aging was performed in a controlled chamber representing a typical indoor industrial environment. Solderability testing on as-fabricated and exposed copper samples was performed with the Sn-Pb eutectic solder at four different reflow temperatures (215, 230, 245 and 260{degrees}C). Rosin mildly activated (RMA), low solids (LS), and citric acid-based (CA) fluxes were included in the evaluation. Under baseline conditions, capillary flow was minimal at the lowest temperatures with all fluxes. Wetting increased with temperature at both baseline and prestressing conditions. Poor wetting, however, was observed at all temperatures with the LS flux. Capillary flow is effectively restored with the CA flux.

Version 6.0 of the IFCI code is being assessed by comparing predictions against the results of several experiments. Simulations of the first two of these experiments, MAGICO-701 and MIXA-6, have been completed with a reasonable level of success. Agreement with the MAGICO-701 experiment was good but was limited somewhat by the inherent problem of numerical diffusion. Results of the MIXA-6 calculations were comparable to those of CHYMES, but clearly suggested the need for an inter-cell radiation transport model in IFCI.

Robotic systems are being developed by the Intelligent Systems and Robotics Center at Sandia National Laboratories to perform automated handling tasks with radioactive nuclear materials. These systems will reduce the occupational radiation exposure to workers by automating operations which are currently performed manually. Because the robotic systems will handle material that is both hazardous and valuable, the safety of the operations is of utmost importance; assurance must be given that personnel will not be harmed and that the materials and environment will be protected. These safety requirements are met by designing safety features into the system using a layered approach. Several levels of mechanical, electrical and software safety prevent unsafe conditions from generating a hazard, and bring the system to a safe state should an unexpected situation arise. The system safety features include the use of industrial robot standards, commercial robot systems, commercial and custom tooling, mechanical safety interlocks, advanced sensor systems, control and configuration checks, and redundant control schemes. The effectiveness of the safety features in satisfying the safety requirements is verified using a Failure Modes and Effects Analysis. This technique can point out areas of weakness in the safety design as well as areas where unnecessary redundancy may reduce the system reliability.

This paper will discuss the design of an input shaped open-loop control for a single flexible robot link. The authors develop the equations of motion, including the first flexible mode shape and the actuator dynamics. Additional content includes the hardware system identification iterative runs used to update the model. Optimized input shaped commands for the flexible robot link to produce a rest-to-rest, residual vibration-free, 90 degree maneuver are developed. Correlation between both experimental and analytical results of the 90{degree} slew, using two different identification models, are reviewed.

SSSPT-F was designed to evaluate sealing materials at WIPP. It demonstrated: (1) the ability to practically and consistently produce ultrafine cementitious grout at the grouting site, (2) successful, consistent, and efficient injection and permeation of the grout into fractured rock at the repository horizon, (3) ability of the grout to penetrate and seal microfractures, (4) procedures and equipment used to inject the grout. Also techniques to assess the effectiveness of the grout in reducing the gas transmissivity of the fractured rock were evaluated. These included gas-flow/tracer testing, post-grout coring, pre- and post-grout downhole televiewer logging, slab displacement measurements, and increased loading on jacks during grout injection. Pre- and post-grout diamond drill core was obtained for use in ongoing evaluations of grouting effectiveness, degradation, and compatibility. Diamond drill equipment invented for this test successfully prevented drill cuttings from plugging fractures in grout injection holes.

There are many approaches to geostatistical simulation that can be used to generate realizations of random fields. These approaches differ fundamentally in a number of ways. First, each approach is inherently different and will produce fields with different statistical and geostatistical properties. Second, the approaches differ with respect to the choice of the features of the region that are to be modeled, and how closely the generated realizations reproduce these features. Some fluctuation in the statistical and geostatistical properties of different realizations of the same random field are natural and desirable, but the proper amount of deviation is an open question. Finally the approaches differ in how the conditioning information is incorporated. Depending on the source of randomness and the uncertainty in the given data, direct conditioning of realizations is not always desirable. In this paper, we discuss and illustrate these differences in order to emphasize the importance of these components in geostatistical simulation.

This paper describes the Twin-Otter SAR Testbed developed at Sandia National Laboratories. This SAR is a flexible, adaptable testbed capable of operation on four frequency bands: Ka, Ku, X, and VHF/UHF bands. The SAR features real-time image formation at fine resolution in spotlight and stripmap modes. High-quality images are formed in real time using the overlapped subaperture (OSA) image-formation and phase gradient autofocus (PGA) algorithms.

This paper describes some of the general weaknesses of the current popular Hypertext Transmission Protocol (HTTP) security standards and products in an effort to show that these standards are not appealing for many applications. The author will then show how one can treat HTTP browsers and servers as untrusted elements in the network so that one can rely on other mechanisms to achieve better overall security than can be attained through today`s security-enhanced HTTP tools.

No abstract available.

We deposited secondary explosive and multilayer thermite films directly onto semiconductor bridges (SCBs) and other substrates. Methods for the deposition of two thermite films (aluminum/copper oxide and magnesium/fluorocarbon polymer) were developed as part of this study and a new capability was obtained for depositing adherent films on any material, including Teflon and Gore-Tex. Our experimental program determined conditions for the SCB ignition of the deposited films, and with the aluminum/copper oxide film, we observed a lower threshold for ignition of a powder pressed against the bridge. We also looked at other ignition methods including lasers, spark discharges, primers and hot combustion gases.

Tonopah Test Range is a unique historic site. Established in 1957 by Sandia Corporation, Tonopah Test Range in Nevada provided an isolated place for the Atomic Energy Commission to test ballistics and non-nuclear features of atomic weapons. It served this and allied purposes well for nearly forty years, contributing immeasurably to a peaceful conclusion to the long arms race remembered as the Cold War. This report is a brief review of historical highlights at Tonopah Test Range. Sandia`s Los Lunas, Salton Sea, Kauai, and Edgewood testing ranges also receive abridged mention. Although Sandia`s test ranges are the subject, the central focus is on the people who managed and operated the range. Comments from historical figures are interspersed through the narrative to establish this perspective, and at the end a few observations concerning the range`s future are provided.

Understanding the frictional properties of advanced Micro-Electro- Mechanical Systems (MEMS) is essential in order to develop optimized designs and fabrication processes, as well as to qualify devices for commercial applications. We develop and demonstrate a method to experimentally measure the forces associated with sliding friction of devices rotating on a hub. The method is demonstrated on the rotating output gear of the microengine recently developed at Sandia National Laboratories. In-situ measurements of an engine running at 18300 rpm give a coefficient of friction of 0.5 for radial (normal) forces less than 4 {mu}N. For larger forces the effective coefficient of friction abruptly increases, suggesting a fundamental change in the basic nature of the interaction between the gear and hub. The experimental approach we have developed to measure the frictional forces associated with the microengine is generically applicable to other MEMS devices.

We describe the implementation and performance of Archimedes 2, an integrated mechanical assembly planning system. Archimedes 2 includes two planners, two assembly sequence animation facilities, and an associated robotic workcell. Both planners use full 3 dimensional data. A rudimentary translator from high level assembly plans to control code for the robotic workcell has also been implemented. We can translate data from a commercial CAD system into input data for the system, which has allowed us to plan assembly sequences for many industrial assemblies. Archimedes 2 has been used to plan sequences for assemblies consisting of 5 to 109 parts. We have also successfully taken a CAD model of an assembly, produced an optimized assembly sequence for it, and translated the plan into robot code, which successfully assembles the device specified in the model.

This work provides a method of mechanical alignment of an array of single mode fibers to an array of optical devices. The technique uses a micromachined metal spring, which captures a vertical, pre- positioned fiber, moves it into accurate alignment, and holds it for attachment. The spring is fabricated from electroplated mickel, using photodefined polyimide as a plating mask. The nickel is plated about 80 {mu}m thick, so that a large fiber depth is captured. In one application, the nickel springs can be aligned to optics on the back side of the substrate. This entire concept is referred to as CLASP (Capture and Locking Alignment Spring Positioner). These springs can be used for general alignment and capture of any fiber to any optical input or output device. Passive alignment of fiber arrays to {plus}/{minus} 2{mu}m accuracy has been demonstrated, with a clear path to improved accuracy.

In conjunction with the affected States as part of their interactions required by the Federal Facilities Compliance Act, the Department of Energy has been developing a process for a disposal configuration for its mixed low-level waste (MLLW). This effort, spanning more than two years, has reduced the potential disposal sites from 49 to 15. The remaining 15 sites have been subjected to a performance evaluation to determine their strengths and weaknesses for disposal of MLLW. The process has included institutional and policy factors as well as strictly technical analyses, and technical analyses must be supported by technical analyses, and technical analyses must be performed within a framework which includes some institutional considerations, with the institutional considerations selected for inclusion largely a matter of policy. While the disposal configuration process is yet to be completed, the experience to date offers a viable approach for solving some of these issues. Additionally, several factors remain to be addressed before an MLLW disposal configuration can be developed.

The integration of optical components with polysilicon surface micromechanical actuation mechanisms show significant promise for signal switching, fiber alignment, and optical sensing applications. Monolithically integrating the manufacturing process for waveguide structures with the processing of polysilicon actuators allows actuated waveguides to take advantage of the economy of silicon manufacturing. The optical and stress properties of the oxides and nitrides considered for the waveguide design along with design, fabrication, and testing details for the polysilicon actuators are presented.

The Environmental Restoration Project at Sandia National Laboratories, New Mexico is tasked with assessment and remediation of the Mixed Waste Landfill in Technical Area 3. The Mixed Waste Landfill is an inactive radioactive and mixed waste disposal site. The landfill contains disposal pits and trenches of questionable location and dimension. Non-intrusive geophysical techniques were utilized to provide an effective means of determining the location and dimension of suspected waste disposal trenches before Resource Conservation and Recovery Act intrusive assessment activities were initiated. Geophysical instruments selected for this investigation included a Geonics EM-31 ground conductivity meter, the new Geonics EM-61 high precision, time-domain metal detector, and a Geometrics 856 total field magnetometer. The results of these non-intrusive geophysical techniques were evaluated to enhance the efficiency and cost-effectiveness of future waste-site investigations at Environmental Restoration Project sites.

This report provides a summary of the field operations associated with the installation of the MRN-1 and MRN-2 test/monitoring wells. These wells were installed in December 1994 and January 1995 as part of the Site-Wide Hydrogeologic Characterization (SWHC) task field program. The SWHC task is part of the Sandia National Laboratories, New Mexico, Environmental Restoration Project carried out by the Environmental Operations Center, 7500. MRN-1 and MRN-2 are paired wells located near the western edge of Kirtland Air Force Base (KAFB), west of Technical Area 3 (TA3), and north of Magazine Road. (Note: MRN stands for Magazine Road North). During the MRN field operations, important subsurface geologic, hydrologic, chemical, and radiological data were obtained. Subsurface geologic data include descriptions of drill cuttings, core, and geophysical logs of the upper unit of the Santa Fe Group. The geology identified here can help determine the eastern limit of the ancestral Rio Grande lithofacies. Subsurface hydrologic data include borehole geophysical logs, and qualitative information obtained during well completion and development. In addition, future aquifer testing at the MRN site will generate data for the interpretation of aquifer parameters such as transmissivity. Samples were taken from core every 100 feet at MRN-1 for chemical and radiological analysis to provide background data for the Environmental Restoration Project.

This report summarizes field operations and hydrogeologic data obtained during installation of the Powerline monitoring/test wells near the western boundary of Kirtland Air Force Base. These wells were installed in 1994 as part of the Site-Wide Hydrogeologic Characterization Project saturated zone investigation. The Site-Wide Hydrogeologic Characterization Project is part of Sandia National Laboratories, New Mexico, Environmental Restoration Project. Three wells were drilled and completed at this location, and named PL-1, PL-2, and PL-3. They are located northwest of Tech Area 3, and are named after a high-voltage powerline located just south of the wells. The objectives of the Powerline wells were to determine the depth to water, complete 2 water table wells and a deeper Santa Fe Group well, to determine the geologic provenance of Santa Fe Group sediments at this location, and to obtain background core samples for radiological analysis. During these field operations, important subsurface hydrogeologic data were obtained. These data include drill cuttings and lithologic descriptions, core samples with background analytical data, geophysical logs, water quality parameters, and water levels. Aquifer tests at the Powerline location will generate data that may yield information on anisotropy in the Santa Fe Group and constrain numerical modeling results that indicate that there is a major northward component of groundwater flow from McCormick Ranch and Tech Area 3 test sites toward City of Albuquerque and KAFB well fields.

Sandia`s STP program is a thallium-based high-temperature superconductor (HTS) research and development program consisting of efforts in powder synthesis and process development, open-system thick film conductor development, wire and tape fabrication, and HTS motor design. The objective of this work is to develop high-temperature superconducting conductors (wire and tape) capable of meeting requirements for high-power electrical devices of interest to industry. The research efforts currently underway are: (1) process development and characterization of thallium-based high-temperature superconducting closed system wire and tape; (2) investigation of the synthesis and processing of thallium-based thick films using two-zone processing; and (3) cryogenic design of a 30K superconducting motor. This report outlines the research that has been performed during FY95 in each of these areas.

In this paper, the authors report values of ion energy distributions and ion angular distributions measured at the grounded electrode of an inductively-coupled discharge in pure chlorine gas. The inductive drive in the GEC reference cell produced high plasma densities (10{sup 11}/cm{sup 3} electron densities) and stable plasma potentials. As a result, ion energy distributions typically consisted of a single peak well separated from zero energy. Mean ion energy varied inversely with pressure, decreasing from 13 to 9 eV as the discharge pressure increased from 20 to 60 millitorr. Half-widths of the ion angular distributions in these experiments varied from 6 to 7.5 degrees, corresponding to transverse energies from 0.13 to 0.21 eV. Ion energies gradually dropped with time, probably due to the buildup of contaminants on the chamber walls. Cell temperature also was an important variable, with ion fluxes to the lower electrode increasing and the ion angular distribution narrowing as the cell temperature increased. Plasmas discharges are widely used to etch semiconductors, oxides and metals in the fabrication of integrated circuits.

A user-defined boundary condition subroutine has been implemented within P3/THERMAL to represent the heat flux between a noncombusting object and an engulfing fire. The heat flux calculations includes a simple 2D fire model in which energy and radiative heat transport equations are solved to produce estimates of the heat fluxes at the fire-object interface. These estimates reflect radiative coupling between a cold object and the flow of hot combustion gases which has been observed in fire experiments. The model uses a database of experimental pool fire measurements for far field boundary conditions and volumetric heat release rates. Taking into account the coupling between a structure and the fire is an improvement over the {sigma}T{sup 4} approximation frequently used as a boundary condition for engineered system response and is the preliminary step in the development of a fire model with a predictive capability. This paper describes the implementation of the fire model as a P3/THERMAL boundary condition and presents the results of a verification calculation carried out using the model.

The development of a constitutive model for representing inelastic flow due to coupled creep, damage, and healing in rock salt is present in this paper. This model, referred to as Multimechanism Deformation Coupled Fracture model, has been formulated by considering individual mechanisms that include dislocation creep, shear damage, tensile damage, and damage healing. Applications of the model to representing the inelastic flow and fracture behavior of WIPP salt subjected to creep, quasi-static loading, and damage healing conditions are illustrated with comparisons of model calculations against experimental creep curves, stress-strain curves, strain recovery curves, time-to-rupture data, and fracture mechanism maps.

A formal description of the structure of several recent performance assessments (PAs) for the Waste Isolation Pilot Plant (WIPP) is given in terms of the following three components: a probability space (S{sub st}, S{sub st}, p{sub st}) for stochastic uncertainty, a probability space (S{sub su}, S{sub su}, p{sub su}) for subjective uncertainty and a function (i.e., a random variable) defined on the product space associated with (S{sub st}, S{sub st}, p{sub st}) and (S{sub su}, S{sub su}, p{sub su}). The explicit recognition of the existence of these three components allows a careful description of the use of probability, conditional probability and complementary cumulative distribution functions within the WIPP PA. This usage is illustrated in the context of the U.S. Environmental Protection Agency`s standard for the geologic disposal of radioactive waste (40 CFR 191, Subpart B). The paradigm described in this presentation can also be used to impose a logically consistent structure on PAs for other complex systems.

A solution of a spacecraft optimal control problem, whose cost function relies on an attitude description, usually depends on the choice of attitude coordinates used. A problem could be solved using 3-2-1 Euler angles or using classical Rodriguez parameters and yield two different ``optimal`` solutions, unless the performance index in invariant with respect to the attitude coordinate choice. Another problem arising with many attitude coordinates is that they have no sense of when a body has tumbled beyond 180{degrees} from the reference attitude. In many such cases it would be easier (i.e. cost less) to let the body complete the revolution than to force it to reverse the rotation and return to the desired attitude. This paper develops a universal attitude penalty function g() whose value is independent of the attitude coordinates chosen to represent it. Furthermore, this function will achieve its maximum value only when a principal rotation of {plus_minus}180{degrees} from the target state is performed. This will implicitly permit the g() function to sense the shortest rotational distance back to the reference state. An attitude penalty function which depends on the Modified Rodriguez Parameters (MRP) will also be presented. These recently discovered MRPs are a non-singular three-parameter set which can describe any three-attitude. This MRP penalty function is simpler than the attitude coordinate independent g() function, but retains the useful property of avoiding lengthy principal rotations of more than {plus_minus}180{degrees}.

The ability to make cost effective, timely decisions associated with waste management and environmental remediation problems has been the subject of considerable debate in recent years. On one hand, environmental decision makers do not have unlimited resources that they can apply to come to resolution on outstanding and uncertain technical issues. On the other hand, because of the possible impending consequences associated with these types of systems, avoiding making a decision is usually not an alternative either. Therefore, a structured, quantitative process is necessary that will facilitate technically defensible decision making in light of both uncertainty and resource constraints. An environmental decision support framework has been developed to provide a logical structure that defines a cost-effective, traceable, and defensible path to closure on decision regarding compliance and resource allocation. The methodology has been applied effectively to waste disposal problems and is being adapted and implemented in subsurface environmental remediation problems.

This paper describes the design of a moving mass trim control system for maneuvering axisymmetric reentry vehicles. The moving mass trim controller is composed of three equal masses that are independently positioned in order to deliver a desired center of mass position. For a slowly spinning reentry vehicle, the mass offset creates a trim angle-of-attack to generate modest flight path corrections. The control system must maintain the desired position of each mass in the face of large disturbances. A novel algorithm for determining the desired mass positions is developed in conjunction with a preliminary controller design. The controller design is based on classical frequency domain techniques where a bound on the disturbance magnitude is used to formulate the disturbance rejection problem. Simulation results for the controller are presented for a typical reentry vehicle.

TRN-1 was drilled near the SE corner of Kirtland Air Force Base to a depth of 510 feet. This well is in the Site-Wide Hydrogeologic Characterization task field program, which is part of Sandia`s Environmental Restoration Project. After drilling, the borehole was logged, plugged to a depth of 352 ft, and completed as a monitoring well. Sand pack interval is from 305 to 352 ft and the screen interval is from 320 to 340 ft. During field operations, important subsurface geologic and hydrologic data were obtained (drill cuttings, geophysical logs of alluvial cover). Identification of the Abo formation in the subsurface will be useful. The subsurface hydrologic data will help define the local hydrostratigraphic framework within the bedrock. Future aquifer testing will be conducted for transmissivity, etc.

Efficient separation of metal species from aqueous streams by precipitation techniques requires a fundamental understanding of the processes that occur during precipitation. These processes include particle nucleation, particle growth by solute deposition, agglomerate formation, and agglomerate breakup. Population balance method has been used to develop a kinetic model that accounts for these competing kinetic processes. The usefulness of the model is illustrated through its application to precipitation of yttrium hydroxynitrate, YHN. Kinetic parameters calculated from the model equations and system-specific solution chemistry are used to describe several aspects of the effect of pH on YHN precipitation. Implications for simultaneous precipitation of more than one cation type are discussed with examples. Effects of solution chemistry, precipitator design, and solvent choice are considered.

This paper presents preliminary work in the development of an avatar driver. An avatar is the graphical embodiment of a user in a virtual world. In applications such as small team, close quarters training and mission planning and rehearsal, it is important that the user`s avatar reproduce his or her motions naturally and with high fidelity. This paper presents a set of special purpose algorithms for driving the motion of the avatar with minimal information about the posture and position of the user. These algorithms utilize information about natural human motion and posture to produce solutions quickly and accurately without the need for complex general-purpose kinematics algorithms. Several examples illustrating the successful applications of these techniques are included.

There has been much recent algorithmic work on the problem of reconstructing the evolutionary history of biological species. Computer virus specialists are interested in finding the evolutionary history of computer viruses--a virus is often written using code fragments from one or more other viruses, which are its immediate ancestors. A phylogeny for a collection of computer viruses is a directed acyclic graph whose nodes are the viruses and whose edges map ancestors to descendants and satisfy the property that each code fragment is ``invented`` only once. To provide a simple explanation for the data, we consider the problem of constructing such a phylogeny with a minimal number of edges. In general, this optimization problem cannot be solved in quasi-polynomial time unless NQP=QP; we present positive and negative results for associated approximated problems. When tree solutions exist, they can be constructed and randomly sampled in polynomial time.

Capacitance-voltage and thermally stimulated current methods are used to investigate radiation induced charge trapping in bipolar base oxides. Results are compared with models of oxide and interface trap charge buildup at low electric fields.

The physical mechanisms for gain degradation in laterals PNP bipolar transistors are examined experimentally and through simulation. The effect of increased surface recombination velocity at the base surface is moderated by positive oxide charge.

Nanostructured materials can be synthesized by utilizing the domain growth that accompanies first-order phase separation. Structural control can be achieved by appropriately selecting the quench depth and the quench time, but in order to do this in a mindful fashion one must understand the kinetics of domain growth. The authors have completed detailed light scattering studies of the evolution of structure in both temperature- and field-quenched phase transitions in two and three dimensional systems. They have studied these systems in the quiescent state and in shear and have developed theoretical models that account for the experimental results.

Low dose rate gain degradation of lateral pnp bipolar transistors can be simulated by accelerated irradiations performed at approximately 135 degrees C. Degradation enhancement is explained by temperature- dependent radiation-induced interface trap formation above the transistor`s base.

A vorticity formulation is described that satisfies the velocity boundary conditions for the incompressible Navier-Stokes equations. Velocity boundary conditions are satisfied by determining the appropriate vortex sheets that must be created on the boundary. Typically, the vortex sheet strengths are determined by solving a set of linear equations that is over-specified. The over-specification arises because an integral constraint on the vortex sheets is imposed. Vortex sheets determined this way do not accurately satisfy both components of the velocity boundary conditions because over-specified systems do not have unique solutions. An integral collocation technique is applied to a generalized Helmholtz decomposition. This formulation implicitly satisfies an integral constraint that is more general that constraints typically used. Improvements in satisfying velocity boundary conditions are shown.

To monitor compliance with a Comprehensive Test Ban Treaty (CTBT), a sensing network, referred to as the International Monitoring System (IMS), is being deployed. Success of the IMS depends on both its ability to preform its function and the international community`s confidence in the system. To ensure these goals, steps must be taken to secure the system against attacks that would undermine it; however, it is not clear that consensus exists with respect to the security requirements that should be levied on the IMS design. In addition, CTBT has not clearly articulated what threats it wishes to address. This paper proposes four system-level threats that should drive IMS design considerations, identifies potential threat agents, and collects into one place the security requirements that have been suggested by various elements of the IMS community. For each such requirement, issues associated with the requirement are identified and rationale for the requirement is discussed.