Publications

In RF telemetry (TM) the allowable RF bandwidth limits the amount of data in the telemetered data set. Typically the data set is less than ideal to accommodate all aspects of a test. In the case of diagnostic data, the compromise often leaves insufficient diagnostic data when problems occur. As a solution, intelligence was designed into a TM, allowing it to adapt to changing data requirements. To minimize the computational requirements for an intelligent TM, a fuzzy logic inference engine was developed. This reference engine was simulated on a PC and then loaded into a TM hardware package for final testing.

This invited paper describes recently reported work on the application of magnetic force microscopy (MFM) to image currents in IC conductors [1]. A computer model for MFM imaging of IC currents and experimental results demonstrating the ability to determine current direction and magnitude with a resolution of {approximately} 1 mA dc and {approximately} 1 {mu}A ac are presented. The physics of MFM signal generation and applications to current imaging and measurement are described.

The high conductivity provided by solder closure joints of component housings is sometimes required to ensure electrical shielding of the components contained within. However, using a soldering iron to produce the solder joints can lead to charring of the insulating materials within the housing. To overcome this problem, the localized heating characteristics of laser soldering can be exploited. Feasibility of laser soldering Sn plated brass housings with a CW Nd:YAG laser has been investigated. It has been determined that laser soldering of these housings using a low solids solder flux is a viable technique and will minimize the amount of heat input to the enclosed electronic components. Metallographic analysis has shown good wetting of the solder on the housing components. Accelerated aging experiments indicate that no significant corrosion potential due to solder flux residues exists. Although a low solids flux was used to make the joints, initial results indicate that a fluxless technique can be developed to eliminate fluxes completely.

A comprehensive environment, safety and health (ES&H) program allocates an extensive portion of its resources to information collection, management, and manipulation. Much of these resources are difficult to obtain and even more costly to ensure that they are sufficiently accurate; however, a system which collects information at the point which a process begins or a material enters a facility and maintains that information throughout its entire life-cycle is a more efficient approach to providing the data necessary to meet ES&H requirements. These data requirements for all the various groups within an ES&H program are associated with the properties and interactions among materials, personnel, facilities, hazards, waste and processes. Although each group is charged with addressing a particular aspect of these properties and interactions, the information they require can be aggregated into a coherent set of common data fields. It is these common data fields that the Cradle-to-Grave Tracking and Information System (CGTIS) is designed to satisfy. Research and development laboratories such as Sandia National Laboratories (SNL) are diverse in nature and, therefore, present a complex challenge to ES&H professionals. The remainder of this paper will describe the CGTIS as envisioned and implemented at SNL, define the requirements of a complete CGTIS, and review the current status of each system module at SNL.

In the early days of microelectronics, design rules and feature sizes were large enough that sub-micron spatial resolution was not needed. Infrared or IR thermal techniques were available that calculated the object`s temperature from infrared emission. There is a fundamental spatial resolution limitation dependent on the wavelengths of light being used in the image formation process. As the integrated circuit feature sizes began to shrink toward the one micron level, the limitations imposed on IR thermal systems became more pronounced. Something else was needed to overcome this limitation. Liquid crystals have been used with great success, but they lack the temperature measurement capabilities of other techniques. The fluorescent microthermographic imaging technique (FMI) was developed to meet this need. This technique offers better than 0.01{degrees}C temperature resolution and is diffraction limited to 0.3 {mu}m spatial resolution. While the temperature resolution is comparable to that available on IR systems, the spatial resolution is much better. The FMI technique provides better spatial resolution by using a temperature dependent fluorescent film that emits light at 612 nm instead of the 1.5 {mu}m to 12 {mu}m range used by IR techniques. This tutorial starts with a review of blackbody radiation physics, the process by which all heated objects emit radiation to their surroundings, in order to understand the sources of information that are available to characterize an object`s surface temperature. The processes used in infrared thermal imaging are then detailed to point out the limitations of the technique but also to contrast it with the FMI process. The FMI technique is then described in detail, starting with the fluorescent film physics and ending with a series of examples of past applications of FMI.

Mechanistic models of aerosol decontamination by an overlying water pool during core debris/concrete interactions and spray removal of aerosols from a Mark I drywell atmosphere are developed. Eighteen uncertain features of the pool decontamination model and 19 uncertain features of the model for the rate coefficient of spray removal of aerosols are identified. Ranges for values of parameters that characterize these uncertain features of the models are established. Probability density functions for values within these ranges are assigned according to a set of rules. A Monte Carlo uncertainty analysis of the decontamination factor produced by water pools 30 and 50 cm deep and subcooled 0--70 K is performed. An uncertainty analysis for the rate constant of spray removal of aerosols is done for water fluxes of 0.25, 0.01, and 0.001 cm{sup 3} H{sub 2}O/cm{sup 2}-s and decontamination factors of 1.1, 2, 3.3, 10, 100, and 1000.

This paper describes the results of testing the MSR-20 radar and provides guidance on how this radar may be used to provide early detection and warning of approaching intruders beyond DOE facility site boundaries.

This report is a compilation of previously unpublished papers pertinent to Stockpile Evaluation, Reliability, and Safety activities at Sandia.

The US Department Energy`s Office of Technology Development has sponsored the development of generic robotics technologies for application to a wide range of remote systems. Of primary interest is the development of technologies which enable faster, safer, and cheaper cleanup of hazardous waste sites than is possible using conventional human contact or remote manual approaches. The development of model-based sensor-directed robot control approaches supports these goals by developing modular control technologies which reduce the time and cost of development by allowing reuse of control system software. In addition, the use of computer models improves the safety of remote site cleanup by allowing automated errors detection and recovery while reducing the time for technology development.

Cellular materials consist of interconnected struts or plates which form cells. The struts or plates are constructed from a variety of metals, polymers, ceramics and wood products. Cellular materials are often used in impact limiters for shipping containers to protect the contents from accidental impact events. These materials exhibit a variety of complex behavior when subjected to crushing loads. This research focuses on the development of continuum representations of cellular solids that can be used in the finite element analysis of shipping container accidents. A significant portion of this work is the development of a new methodology to relate localized deformations to appropriate constitutive descriptions. This methodology provides the insight needed to select constitutive descriptions for cellular solids that capture the localized deformations that are observed experimentally. Constitutive relations are developed for two different cellular materials, aluminum honeycomb and polyurethane foam. These constitutive relations are based on plasticity and continuum damage theories. Plasticity is used to describe the permanent deformation exhibited by both aluminum honeycomb and polyurethane foam. Continuum damage is needed to capture the change in elastic parameters due to cracking of the polyurethane cell wall materials. The new constitutive description of polyurethane foam is implemented in both static and dynamic finite element codes, and analytical and numerical predictions are compared with available experimental data.

This report revises and updates the geologic site characterization report that was published in 1980. Revised structure maps and sections show interpretative differences in the dome shape and caprock structural contours, especially a major east-west trending shear zone, not mapped in the 1980 report. Excessive gas influx in Caverns 18 and 20 may be associated with this shear zone. Subsidence values at Bayou Choctaw are among the lowest in the SPR system, averaging only about 10 mm/yr but measurement and interpretation issues persist, as observed values often approximate measurement accuracy. Periodic, temporary flooding is a continuing concern because of the low site elevation (less than 10 ft), and this may intensify as future subsidence lowers the surface even further. Cavern 4 was re-sonared in 1992 and the profiles suggest that significant change has not occurred since 1980, thereby reducing the uncertainty of possible overburden collapse -- as occurred at Cavern 7 in 1954. Other potential integrity issues persist, such as the proximity of Cavern 20 to the dome edge, and the narrow web separating Caverns 15 and 17. Injection wells have been used for the disposal of brine but have been only marginally effective thus far; recompletions into more permeable lower Pleistocene gravels may be a practical way of increasing injection capacity and brinefield efficiency. Cavern storage space is limited on this already crowded dome, but 15 MMBBL could be gained by enlarging Cavern 19 and by constructing a new cavern beneath and slightly north of abandoned Cavern 13. Environmental issues center on the low site elevation: the backswamp environment combined with the potential for periodic flooding create conditions that will require continuing surveillance.

This 1992 report contains monitoring data from routine radiological and nonradiological environmental surveillance activities. summaries of significant environmental compliance programs in progress, such as National Environmental Policy Act documentation, environmental permits, envirorunental restoration, and various waste management programs for Sandia National Laboratories in Albuquerque, New Mexico, are included. The maximum offsite dose impact was calculated to be 0.0034 millirem. The total population within a 50-mile radius of Sandia National Laboratories/New Mexico received an estimated collective dose of 0.019 person-rem during 1992 from the laboratories` operations. As in the previous year, the 1992 operations at Sandia National Laboratories/New Mexico had no discernible impact on the general public or on the environment.

The Bibliographic Retrieval System (BARS) is a database management system specially designed to retrieve bibliographic references. Two databases are available, (i) the Sandia Shock Compression (SSC) database which contains over 5600 references to the literature related to stress waves in solids and their applications, and (ii) the Shock Physics Index (SPHINX) which includes over 6200 further references to stress waves in solids, material properties at intermediate and low rates, ballistic and hypervelocity impact, and explosive or shock fabrication methods. There is some overlap in the information in the two data bases.

The Bibliographic Retrieval System (BARS) is a database management system specially designed to store and retrieve bibliographic references and track documents. The system uses INGRES to manage this database and user interface. It uses forms for journal articles, books, conference proceedings, theses, technical reports, letters, memos, visual aids, as well as a miscellaneous form which can be used for data sets or any other material which can be assigned an access or file number. Sorted output resulting from flexible BOOLEAN searches can be printed or saved in files which can be inserted in reference lists for use with word processors.

A Sandia project currently uses an outdated Magnavox 6400 Global Positioning System (GPS) receiver as the core of its navigation system. The goal of this study was to analyze the performance of the current GPS receiver compared to newer, less expensive models and to make recommendations on how to improve the performance of the overall navigation system. This paper discusses the test methodology used to experimentally analyze the performance of different GPS receivers, the test results, and recommendations on how an upgrade should proceed. Appendices contain detailed information regarding the raw data, test hardware, and test software.

The MC4169 Double-Layer Capacitor Assembly was developed in response to a request from the B61 Systems organization to provide interim power for the B61 Common JTA Development. The project has been successfully completed, and Lot 1 has been built by MMSC/GEND. Development testing showed that this assembly met all design requirements. This report describes the design configuration, environmental testing, and aging, reliability, and safety studies done to ensure that the design requirements were met.

The procedures of vapor-deposition polymerization, spin coating and orientation-dependent etching have been employed to make free-standing thin films of Parylene-N, Parylene-D, polystyrene, polycarbonate and perfluoro-dimethyl-dioxole/tetrafluoroethylene copolymer (Teflon{reg_sign} AF-1600). The polymeric materials were vapor-deposited or spin-coated onto substrates of polished single-crystal silicon (wafers) and removed on frames of various shapes and sizes after application of adhesive and an etching process using potassium hydroxide. Thicknesses range from 2000{Angstrom} to 12000{Angstrom}.

This paper describes the major differences in the IDEFlX and NIAM ISDM information modeling methodologies and presents the different philosophies behind these methodologies. The IDEFlX methodology base document comes from the Integrated Information Support System (IISS) project sponsored by the US Air Force. The IISS project office was contacted and they supplied the referenced document as the best base description of this methodology. The NIAM ISDM methodology base documents present the general NIAM methodology. IDEFlX is a variant of the entity-attribute-relationship (E-A-R) approach to data modeling and although many other variants exist, the comparison presented here covers the common aspects of entity-relationship approaches. This comparison identifies and illustrates the differences in the two methodologies.

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The effort to consolidate the ``islands of information`` within an enterprise -- to manage information at the enterprise level rather than the department or sub-system level -- is known by many names, such as ``Information Resource Management`` and ``Corporate Data Administration``. Here we will call it ``Enterprise Information Management`` (EIM). This effort is becoming increasingly vital as the need for shared information grows, yet it is plagued by costly, time-consuming efforts that produce reams of hard-to-maintain documentation. The results are difficult to integrate, measure, or apply. Management needs a tool that can integrate models from diverse modeling efforts into a global knowledge base, produce metrics to clarify the value of the integration process, and provide a short, traceable route between information models and their physical implementations. The natural-language emphasis of NIAM makes it an ideal candidate for this tool. When integrated with enterprise-wide data administration, the collection of metrics, CASE tools that produce application code, and automated support tools, NIAM can effectively manage multiple Universes of Discourse (UOD). Prototypes of automated support tools, ``Fact Manager`` and ``Fact Designer``, will be discussed.

At the Semiconductor Technology Workshop, held in November 1992, the Semiconductor Industry Association (SIA) convened 179 semiconductor technology experts to assess the 15-year outlook for the semiconductor manufacturing industry. The output of the Workshop, a document entitled ``Semiconductor Technology: Workshop Working Group Reports,`` contained an overall roadmap for the technology characteristics envisioned in integrated circuits (ICs) for the period 1992--2007. In addition, the document contained individual roadmaps for numerous key areas in IC manufacturing, such as film deposition, thermal processing, manufacturing systems, exposure technology, etc. The SIA Report did not contain a separate roadmap for contamination free manufacturing (CFM). A key component of CFM for the next 15 years is the use of sensors for (1) defect reduction, (2) improved product quality, (3) improved yield, (4) improved tool utilization through contamination reduction, and (5) real time process control in semiconductor fabrication. The objective of this Focus Team is to generate a Sensors for Process Control Roadmap. Implicit in this objective is the identification of gaps in current sensor technology so that research and development activity in the sensor industry can be stimulated to develop sensor systems capable of meeting the projected roadmap needs. Sensor performance features of interest include detection limit, specificity, sensitivity, ease of installation and maintenance, range, response time, accuracy, precision, ease and frequency of calibration, degree of automation, and adaptability to in-line process control applications.

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Quality management is more than an idea whose time has come, more than a passing fancy. Quality will be an imperative for competitiveness in the 21st century. Many large US firms have already implemented or are considering implementing total quarry management practices and processes. While most of the current literature on quality management focuses on large firms, quality management is arguably even more relevant to small businesses. As global markets become increasingly a reality in today`s world, small business managers and owners must focus on customer, satisfaction and continuous improvement if they are to survive the global competitive battle. Quality management may not be a luxury but rather, an essential focus for successful small business oompetitiveness. This paper examines quality management practices, awareness level, needs, and successes for small businesses in the Rocky Mountain region of the United States. This region is especially dependent upon small business competitiveness for economic survival and growth. A significant percent of total employment and sales in this region of the US is attributable to businesses classified as small. The specific purposes of the paper are: to report the results of a survey of small manufacturers` use, success, awareness, and interest in quality management practices and programs; to provide a profile of those manufacturers who have implemented quality management programs; and to describe a unique partnership between a state university and a large national lab designed to assist small business owners and managers in evaluating and implementing total quality management techniques.

This paper proposes a framework for the comprehensive analysis of complex problems in probabilistic structural mechanics. Tools that can be used to accurately estimate the probabilistic behavior of mechanical systems are discussed, and some of the techniques proposed in the paper are developed and used in the solution of a problem in nonlinear structural dynamics.

Sandia National Laboratories (SNL) Instrumentation Development Department was tasked by the Defense Nuclear Agency (DNA) to record data on Tektronix RTD720 Digitizers on the HUNTERS TROPHY field test conducted at the Nevada Test Site (NTS) on September 18, 1992. This report contains a overview and description of the computer hardware and software that was used to acquire, reduce, and display the data. The document is divided into two volumes: an overview and operators manual (Volume 1) and a maintenance manual (Volume 2).

An automated system to characterize cable systems at NTS has been developed to test the feasibility of such a system. A rack of electronic equipment including a fast pulse generator, digital sampling scope, coaxial switch matrix and GPIB controller was installed downhole at NTS for the Hunters Trophy event. It was used to test automated characterization. Recorded measurements of simulation and other instrument data were gathered to determine if a full scale automated system would be practical in full scale underground nuclear effects tests. The benefits of such a full scale system would be fewer personnel required downhole; more instrument control in the uphole recording room; faster acquisition of cable parameter data.

Recent work has shown that near-interfacial oxide traps that communicates with the underlaying Si (``border traps``) can play a significant role in determining MOS radiation response and long-term reliability. Thermally-stimulated-current 1/f noise, and frequency-dependent charge-pumping measurements have been used to estimate border-trap densities in MOS structures. These methods all require high-precision, low-noise measurements that are often difficult to perform and interpret. In this summary, we describe a new dual-transistor method to separate bulk-oxide-trap, interface-trap, and border-trap densities in irradiated MOS transistors that requires only standard threshold-voltage and high-frequency charge-pumping measurements.

A new package for the air transport of hazardous materials is currently being developed in the Transportation Systems Department at Sandia National Laboratories. The baseline design has a unique impact limiter which uses layers of aluminum screen wire and aramid cloth fabric. A primary motivation for selecting this unusual combination of materials is the need for the impact limiter to not only limit the amount of load transmitted to the primary container but also remain in place during impact events so that it provides a thermal barrier during a subsequent fire. A series of uniaxial and confined compression tests indicated that the layered material does not behave like other well characterized materials. No existing constitutive models were able to satisfactorily capture the behavior of the layered material; thus, a new plasticity model was developed. The new material model was then used to characterize the response of air transport packages with layered impact limiters to hypothetical accidental impact events. Responses predicted by these analyses compared favorably with experiments at Sandia`s rocket sled test facility in which a one-fourth scale package was subjected to side and end impacts at velocities of 428 and 650 fps, respectively.

This report provides an overview of the containers that are currently stored at Pantex and available for use in response to an accident or for use in any other application where a sealed containment vessel and accident resistant overpack may be needed.

The Robotic All Terrain Lunar Exploration Rover (RATLER) design concept began at Sandia National Laboratories in late 1991 with a series of small, proof-of-principle, working scale models. The models proved the viability of the concept for high mobility through mechanical simplicity, and eventually received internal funding at Sandia National Laboratories for full scale, proof-of-concept prototype development. Whereas the proof-of-principle models demonstrated the mechanical design`s capabilities for mobility, the full scale proof-of-concept design currently under development is intended to support field operations for experiments in telerobotics, autonomous robotic operations, telerobotic field geology, and advanced man-machine interface concepts. The development program`s current status is described, including an outline of the program`s work over the past year, recent accomplishments, and plans for follow-on development work.

Four series of cyclic direct-shear experiments were conducted on several replicas of three natural fractures and a tensile fracture of welded tuff from Yucca Mountain. The objective of these tests was to examine the effect of cyclic loading on joint shear behavior under different boundary conditions. The shear tests were performed under either different levels of constant normal load ranging between 0.6 and 25.6 kips (2.7 and 113.9 kN) or constant normal stiffness ranging between 14.8 and 187.5 kips/in (25.9 and 328.1 kn/cm) . Bach test in the two categories consisted of five cycles of forward and reverse shear. Normal compression tests were also performed both before and after each shear experiment to measure changes in joint normal deformability. In order to quantify fracture surface damage during shear, fracture-surface fractal dimensions were obtained from measurements before and after shear.

Four series of cyclic direct-shear experiments were conducted on several replicas of three natural fractures and a laboratory-developed tensile fracture of welded tuff from Yucca Mountain to test the graphical load-displacement analysis method proposed by Saeb (1989) and Amadei and Saeb (1990). Based on the results of shear tests conducted on several joint replicas under different levels of constant normal load ranging between 0.6 and 25.6 kips (2.7 and 113.9 kN), the shear behavior of joint replicas under constant normal stiffness ranging between 14.8 and 187.5 kips/in. (25.9 and 328.1 kN/cm) was predicted by using the graphical method. The predictions were compared to the results of actual shear tests conducted for the same range of constant normal stiffness. In general, a good agreement was found between the predicted and the observed shear behavior.

The task of routing a 2-relation on an n-processor completely connected optical communication parallel computer (OCPC) is considered. A lower bound is presented that applies to any randomized distributed algorithm for this task: specifically, it is shown that the expected number of steps required to route a 2-relation is {Omega}({radical} log log n) in the worst case. For comparison, the best upper bound known is O(log log n).

Today, 109 nuclear power plants provide over 20 percent of the electrical energy generated in the US. The operating license of the first of these plants will expire in the year 2000; one third of the operating licenses will expire by 2010 and the remaining plant licenses are scheduled to expire by 2033. The National Energy Strategy assumes that 70 percent of these plants will continue to operate beyond their current license expiration to assist in ensuring an adequate, diverse, and environmentally acceptable energy supply for economic growth. In order to preserve this energy resource in the US three major tasks must be successfully completed: (1) establishment of the regulations, technical standards, and procedures for the preparation and review of a license renewal application; (2) development, verification, and validation of the various technical criteria and bases for needed monitoring, refurbishment, or replacement of plant equipment; and (3) demonstration of the regulatory process. Since 1985, the US Department of Energy (DOE) has been working with the nuclear industry and the US Nuclear Regulatory Commission (NRC) to establish and demonstrate the option to extend the life of nuclear power plants through the renewal of operating licenses. This paper focuses primarily on DOE`s Plant Lifetime Improvement (PLIM) Program efforts to develop the technical criteria and bases for effective aging management and lifetime improvement for continued operation of nuclear power plants. This paper describes current projects to resolve generic technical issues, including degradation of long-lived components, reactor pressure vessel (RPV) embrittlement management approaches, and analytical methodologies to characterize RPV integrity.

The Weapons Evaluation Test Laboratory (WETL), operated by Sandia Laboratories at the Pantex Plant in Amarillo, Texas, is engaged primarily in the testing of weapon systems in the stockpile or of newly produced weapon systems for the Sandia Surety Assessment Center. However, the WETL`s unique testing equipment and data-handling facilities are frequently used to serve other organizations. Service to other organizations includes performing special tests on weapon components, subassemblies, and systems for purposes such as basic development and specific problem investigation. The WETL staff also sends equipment to other laboratories for specific tests that cannot be performed at Pantex. For example, we modified and sent equipment to Brookhaven National Laboratory for testing with their Neutral Particle Beam. WETL supplied the engineering expertise to accomplish the needed modifications to the equipment and the technicians to help perform many special tests at Brookhaven. A variety of testing is possible within the WETL, including: Accelerometer, decelerometer, and G-switch g-level/closure testing; Neutron generator performance testing; weapon systems developmental tests; weapon system component testing; weapon system failure-mode-duplication tests; simultaneity measurements; environmental extreme testing; parachute deployment testing; permissive action link (PAL) testing and trajectory-sensing signal generator (TSSG) testing. WETL`s existing equipment configurations do not restrict the testing performed at the WETL. Equipment and facilities are adapted to specific requirements. The WETL`s facilities can often eliminate the need to build or acquire new test equipment, thereby saving time and expense.

This document introduces photovoltaic technology to individuals and groups specializing in development activities. Examples of actual installations illustrate the many services supplied by photovoltaic systems in development applications, including water pumping, lighting, health care, refrigeration, communications, and a variety of productive uses. The various aspects of the technology are explored to help potential users evaluate whether photovoltaics can assist them in achieving their organizational goals. Basic system design, financing techniques, and the importance of infrastructure are included, along with additional sources of information and major US photovoltaic system suppliers.

Any advance beyond the density of standard 2D Multichip Modules (MCM) will require a vertical interconnect technology that can produce reliable area array interconnection with small feature sizes. Laser drilled vertical vias have been controllably produced in standard silicon (Si) wafers down to 0.035mm (0.0014 inches) in diameter. Several laser systems and their system parameters have been explored to determine the optimum parametric set for repeatable vias in Si. The vias produced have exhibited clean smooth interior surfaces with an aspect ratio of up to 20:1 with little or no taper. All laser systems used, their system parameters, design modifications, theory of operation, and drilling results are discussed.

Properties of the ionosphere are reviewed along with its correlations with other geophysical phenomena and with applications of ionospheric studies to communication, navigation, and surveillance systems. Computer tomography is identified as a method to determine the detailed, three-dimensional distribution of electron density within the ionosphere. Several tomography methods are described, with a basic approach illustrated by an example. Limitations are identified.

A method is presented to unfold the two-dimensional vertical structure in electron density by using data on the total electron content for a series of paths through the ionosphere. The method uses a set of orthonormal basis functions to represent the vertical structure and takes advantage of curved paths and the eikonical equation to reduce the number of iterations required for a solution. Curved paths allow a more thorough probing of the ionosphere with a given set of transmitter and receiver positions. The approach can be directly extended to more complex geometries.

This memorandum is a synopsis of the description and operation of the equipment used and the events occurring during the calibration of various accelerometers at the Dropball Station.

An Ion Mobility Spectrometer (IMS) was used to determine the detection limits of RDX and TNT on six different substrates. The preparation of the explosive deposits on the surfaces is examined as well as effects due to the size, uniformity, method of application, and time that a deposit has been on a surface. Sampling methods are discussed along with effects of the surface topology. The transfer of explosives from a hand to a surface, and methods to reduce the detection limits are presented.

Error propagation equations, based on the Taylor series model, are derived for the nondimensional ratios and coefficients most often encountered in high-speed wind tunnel testing. These include pressure ratio and coefficient, static force and moment coefficients, dynamic stability coefficients, calibration Mach number and Reynolds number. The error equations contain partial derivatives, denoted as sensitivity coefficients, which define the influence of free-stream Mach number, M{infinity}, on various aerodynamic ratios. To facilitate use of the error equations, sensitivity coefficients are derived and evaluated for nine fundamental aerodynamic ratios, most of which relate free-stream test conditions (pressure, temperature, density or velocity) to a reference condition. Tables of the ratios, R, absolute sensitivity coefficients, {partial_derivative}R/{partial_derivative}M{infinity}, and relative sensitivity coefficients, (M{infinity}/R) ({partial_derivative}R/{partial_derivative}M{infinity}), are provided as functions of M{infinity}.

Sandia National Laboratories has developed a high security fiber optic seal that incorporates tamper resistance features that are not available in commercial fiber optic seals. The Python Seal is a passive fiber optic loop seal designed to give indication of unauthorized entry. The seal includes a fingerprint feature that provides seal identity information in addition to the unique fiber optic pattern created when the seal is installed. The fiber optic cable used for the seal loop is produced with tamper resistant features that increase the difficulty of attacking that component of a seal. A Seal Reader has been developed that will record the seal signature and the fingerprint feature of the seal. A Correlator software program then compares seal images to establish a match or mismatch. SNL is also developing a Polaroid reader to permit hard copies of the seal patterns to be obtained directly from the seal.

The Authenticated Tracking and Monitoring System (ATMS) has been designed to address the need for global monitoring of the status and location of proliferation-sensitive items. Conceived to utilize the proposed Global Verification and Location System (GVLS) satellite link, ATMS could use the existing International Maritime Satellite commercial communication system until GVLS is operational. The ATMS concept uses sensor packs to monitor items and environmental conditions, collects a variety of events data through a sensor processing unit, and transmits the data to a satellite, which then sends data to ground stations. Authentication and encryption algorithms will be used to secure the data. A typical ATMS application would be to track and monitor the safety and security of a number of items in transit along a scheduled shipping route. This paper also discusses a possible proof-of-concept system demonstration.

An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small (Macrostatistical Hydrodynamics). First, we describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with such a flow-induced, spatially varying concentration, one must know how the viscosity of a homogeneous suspension depends on such variables as solids concentration and particle orientation. We suggest the technique of falling ball viscometry, using small balls, as a method to determine the effective viscosity of a suspension without affecting the original microstructure significantly. We also describe data from experiments in which the detailed fluctuations of a falling ball`s velocity indicate the noncontinuum nature of the suspension and may lead to more insights into the effects of suspension microstructure on macroscopic properties. Finally, we briefly describe other experiments that can be performed in quiescent suspensions (in contrast to the use of conventional shear rotational viscometers) in order to learn more about the microstructure and boundary effects in concentrated suspensions.

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This bulletin depicts current research on manufacturing technology at Sandia laboratories. An automated, adaptive process removes grit overspray from jet engine turbine blades. Advanced electronic ceramics are chemically prepared from solution for use in high- voltage varistors. Selective laser sintering automates wax casting pattern fabrication. Numerical modeling improves performance of photoresist stripper (simulation on Cray supercomputer reveals path to uniform plasma). And mathematical models help make dream of low- cost ceramic composites come true.

MIMD massively parallel computers promise unique power and flexibility for engineering and scientific simulations. In this paper we review the development of a number of software methods and algorithms for scientific and engineering problems which are helping to realize that promise. We discuss new domain decomposition, load balancing, data layout and communications methods applicable to simulations in a broad range of technical field including signal processing, multi-dimensional structural and fluid mechanics, materials science, and chemical and biological systems.

In this paper we describe an algorithm for generating virtual forces in a bilateral teleoperator system. The virtual forces are generated from a world model and are used to provide real-time obstacle avoidance and guidance capabilities. The algorithm requires that the slaves tool and every object in the environment be decomposed into convex polyhedral Primitives. Intrusion distance and extraction vectors are then derived at every time step by applying Gilbert`s polyhedra distance algorithm, which has been adapted for the task. This information is then used to determine the compression and location of nonlinear virtual spring-dampers whose total force is summed and applied to the manipulator/teleoperator system. Experimental results validate the whole approach, showing that it is possible to compute the algorithm and generate realistic, useful psuedo forces for a bilateral teleoperator system using standard VME bus hardware.

Hydropyrolysis is potentially an attractive means for the production of synthetic fuels and chemical feedstocks from coals. It offers a simpler process configuration than traditional direct liquefaction with a higher throughput and avoids problems with liquid (tar)-solids (residue) separation. Recent evaluations of coal liquefaction processes have concluded that, provided 50% or more distillable liquids can be produced, hydropyrolysis will be a viable alternative to the traditional vehicle solvent-based processes. For low-rank coals, hydrogenation catalysts are much less effective than for their bituminous counterparts with the increases in tar yields being typically less than 10% daf coal{sup 6}. Nonetheless, without catalyst, the tar yields of 40--50% at 150 bar pressure are appreciably higher than for bituminous coals. In this investigation, tests have been conducted at temperatures up to 600{degrees}C and using an extremely low heating rate of 5{degrees}C/min on the Wyodak Argonne Premium Coal Sample (APCS) and the high-sulfur Mequinenza and Rasa lignites to ascertain whether tar yields could be further increased without catalyst. It was initially considered that the tar yields for low rank coals are limited by the fact that retrogressive reactions, particularly those involving phenolic and carboxylic moities, are more prevalent than for bituminous coals. Data obtained indicates that low heating rates do, in fact, improve the conversion for low-rank coals.