Publications

N-CART (the National Spent Nuclear Fuel Program Cost Analysis and Risk Tool) is being developed to aid in low-risk, cost-effective, timely management of radioactive waste and spent nuclear fuel, and can therefore be used in management of mixed waste. N-CART provides evaluation of multiple alternatives and presents the consequences of proposed waste management activities in a clear and concise format. N-CART`s decision-aiding analyses include comparisons and sensitivity analyses of multiple alternatives and allows the user to perform quick turn-around {open_quotes}what if{close_quotes} studies to investigate various scenarios. Uncertainties in data (such as cost and schedule of various activities) are represented as distributions. N-CART centralizes documentation of the bases of program alternatives and program decisions, thereby supporting responses to stakeholders concerns. The initial N-CART design considers regulatory requirements, costs, and schedules for alternative courses of action. The final design will include risks (public health, occupational, economic, scheduling), economic benefits, and the impacts of secondary waste generation. An optimization tool is being incorporated that allows the user to specify the relative importance of cost, time risks, and other bases for decisions. The N-CART prototype can be used to compare the costs and schedules of disposal alternatives for mixed low-level radioactive waste (MLLW) and greater-than-Class-C (GTCC) waste, as well as spent nuclear fuel (SNF) and related scrap material.

The use of dendrimers for preparing chemically sensitive interfaces for detecting volatile organic compounds (VOCs) using surface acoustic wave (SAW) device transducers is described. Specifically, the synthesis of the dendrimers and the means by which they are affixed to SAW devices is discussed, followed by a detailed spectroscopic analysis of the surface-confined dendrimers and a discussion of their interaction with different VOCs. Most of these preliminary experiments focus on dendrimer surface modification using benzoylchloride, which leads to phenyl terminal groups linked to the dendrimer via amide groups. The results of this study lead us to conclude that dendrimers: (1) provide general specificity towards classes of functional groups and are therefore suitable for array-based sensing schemes; (2) are intermediate in structure between monolayers and polymers and exhibit the desirable properties of both; (3) can be straightforwardly attached to the surfaces of acoustic wave devices.

Boron-doped back-surface fields (BSF`s) have potentially superior performance compared to aluminum-doped BSF`s due to the higher solid solubility of boron compared to aluminum. However, conventional boron diffusions require a long, high temperature step that is both costly and incompatible with many photovoltaic-grade crystalline-silicon materials. We examined a process that uses a relatively low-temperature aluminum-alloy process to obtain a boron-doped BSF by doping the aluminum with boron. In agreement with theoretical expectations, we found that thicker aluminum layers and higher boron doping levels improved the performance of aluminum-alloyed BSF`s.

Zinc polyphosphate glasses were examined as potential candidates for low temperature sealing applications. Glass-formation and properties were determined for the ZnO-P{sub 2}O{sub 5}, ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5} and ZnO-SnO-P{sub 2}O{sub 5} systems, and information about the short-range structures of these glasses was obtained by Raman and solid state nuclear magnetic resonance spectroscopies. In general, the most durable polyphosphate glasses have structures based on relatively short pyrophosphate chain lengths (i.e., 2 P-tetrahedra). Modified phosphate compositions are given, including compositions used to seal float glass substrates at temperatures as low as 500{degrees}C.

The purpose of hazardous and radioactive materials packaging is to enable these materials to be transported without posing a threat to the health or property of the general public. To achieve this aim, regulations in the US have been written establishing general design requirements for such packagings. While no regulations have been written specifically for mixed waste packaging, regulations for the constituents of mixed wastes, i.e., hazardous and radioactive substances, have been codified by the US Department of Transportation and the US Nuclear Regulatory Commission. Based on these national requirements, a Chemical Compatibility Testing Program was developed in the Transportation Systems Department at SNL. In this paper, the authors present the results of Part B of the second phase of this testing program. The first phase screened five liner materials and six seal materials towards four simulant mixed wastes. Part A of the second phase involved the comprehensive testing of five candidate liner materials to an aqueous Hanford Tank simulant mixed waste. Part B involved similar testing on elastomeric materials, ethylene-propylene and butadiene-acrylonitrile rubber. The comprehensive testing protocol involved exposing the respective materials to a matrix of four gamma radiation doses ({approximately}1, 3, 6, and 40 kGy), three temperatures (18, 50, and 60 C), and four exposure times (7, 14, 28, and 180 days). Following their exposure to these combinations of conditions, the materials were evaluated by measuring six material properties. These properties were specific gravity, dimensional changes, hardness, vapor transport rates, compression set, and mechanical properties.

A survey of robotic applications in radioactive environments has been conducted, and analysis of robotic system components and their response to the varying types and strengths of radiation has been completed. Two specific robotic systems for accident recovery and nuclear fuel movement have been analyzed in detail for radiation hardness. Finally, a general design approach for radiation-hardened robotics systems has been developed and is presented. This report completes this project which was funded under the Laboratory Directed Research and Development program.

The theme of this year`s Annual Meeting is ``Ancient Wisdom-Future Technology.`` The panel assembled for this session has been asked to think metaphorically about the theme and how it relates to their profession of human factors and ergonomics. Originally conceived as a debate centering around the older technologies and research techniques versus the newer ways of finding answers, it was soon realized that there was no dichotomy, but more of a synergy between the old and the new. If human factors is truly a philosophy of design rather than simply a body of knowledge, then one would expect consistency in approach regardless of field of application or new discoveries of human performance. Just as when two or more rivers combine to become a force mightier than the simple summation, the synergistic power of established techniques or knowledge and recent innovation is available to everyone in the profession. The invited panelists represent diverse perspectives in human factors and ergonomics, and this made for a stimulating discussion.

Efficient techniques for rapid tritium removal will be necessary for ITER to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO{sub 2} or Nd:Yag laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm{sup 2} flux with an exposure time of order 10 ms is suitable to heat a 50 micron co-deposited layer to 1,000--2,000 degrees. Improved wall conditioning may be a significant side benefit. They identify remaining issues that need to be addressed experimentally.

A simultaneous PVDF/VISAR measurement technique was used for isentropic-loading experiments with a polymethyl methacrylate (PMMA) specimen. The experiments used a graded density impactor accelerated onto a tantalum driver backed with PMMA and then lithium fluoride windows for each experiment. Simultaneous measurements made at each window interface provided precise transit time and particle velocity measurements which can be used to determine the stress-vs-strain loading path using Lagrangian analysis techniques. The experimental technique provides access to 40 GPa stress levels in PMMA under isentropic-loading conditions.

Lightning data, recorded with satellite optical sensors, are compared with extremely low frequency (ELF) and Schumann resonance (SR) data from the Sprites `96 Campaign. The satellite data are broad-band visible events recorded by the M46 satellite payload. Full width at half maximum and optical tail durations from the satellite data are compared with ELF slow tail features and Schumann resonance spectral color. In addition, continuing current estimates were computed for several positive cloud-to-ground (PCG) strokes. These estimates were derived using relative optical intensities from the satellite data and a peak current measurement from National Lightning Detection Network (NLDN) data. This assessment of M46 lightning data supports correlations between visible and ELF signatures. More data must be studied for compelling proof.

Providing uncontaminated weapon internal atmosphere samples and measuring their dew points is of paramount importance for enhanced surveillance and accelerated aging. The authors are developing and integrating four types of gas sampling systems for use throughout the weapons complex. They are utilizing tools to extract time/age information from the gas analysis of weapon internal atmospheres.

This paper discusses the reliability of several photovoltaic projects including SMUD`s PV Pioneer project, various projects monitored by Ascension Technology, and the Colorado Parks project. System times-to-failure range from 1 to 16 years, and maintenance costs range from 1 to 16 cents per kilowatt-hour. Factors contributing to the reliability of these systems are discussed, and practices are recommended that can be applied to future projects. This paper also discusses the methodology used to collect and analyze PV system reliability data.

Vapor diffusion in porous media in the presence of its liquid has often been analyzed like air diffusion. The diffusion rate is much lower than in free space due to the presence of the porous medium and any liquid present. However, enhanced vapor diffusion has also been postulated such that the diffusion rate may approach free-space values. The mechanisms postulated to lead to this enhancement include condensation/evaporation across isolated liquid islands in the porous media and an increased temperature gradient in the gas phase. In order to try to understand the mechanisms involved in such an enhancement, pore-scale models have been developed. Vapor diffusion in the presence of liquid islands has been evaluated for a one-dimensional pore network under a concentration gradient. The simulations show that significant enhancement of vapor diffusion is indeed possible in the presence of liquid islands, while air diffusion decreases slightly. While the present pore-scale model indicates that enhanced vapor diffusion is possible, only experimental data can confirm the relevant processes.

Several analysis methods have been applied to evaluate the structure and composition of the electrode/adhesive interfaces i previously fielded M2370 Fire Sets. A method of interfacial fracture at cryogenic temperatures as been employed to expose regions of these interfaces at multiple levels in a SFE stack. Electron microscopy shows that bond failure induced by the fracture is predominantly adhesive with an equal probability of failure of the Au and Cu interfaces. Some evidence for cohesive, indicative of a possible microstructure related to electrical breakdown. Pinhole-free larger regions of adhesive also exist which may explain the observed high resistance in impedance measurements.

Shock-induced depoling of the ferroelectric PZT 95/5 has been utilized in pulsed power applications for many years. Recently, new design and certification requirements have generated a strong interest in numerically simulating the operation of pulsed power devices. Because of a scarcity of relevant experimental data obtained within the past twenty years, we have initiated an extensive experimental study of the dynamic behavior of this material in support of simulation efforts. The experiments performed to date have been limited to examining the behavior of unpoled material. Samples of PZT 95/5 have been shocked to axial stresses from 0.5 to 5.0 GPa in planar impact experiments. Impact face conditions have been recorded using PVDF stress gauges, and transmitted wave profiles have been recorded either at window interfaces or at a free surface using laser interferometry (VISAR). The results significantly extend the stresses examined in prior studies of unpoled material, and ensure that a comprehensive experimental characterization of the mechanical behavior under shock loading is available for continuing development of PZT 95/5 material models.

We describe a new approach to second-order nonlinear optical materials, namely quadrupoling. This approach is valid in the regime of Kleinman (full permutation) symmetry breaking, and thus requires a two- or three dimensional microscopic nonlinearity at wavelengths away from material resonances. This {open_quotes}quadrupolar{close_quotes} nonlinearity arises from the second rank pseudotensor of the rotationally invariant representation of the second-order nonlinear optical tensor. We have experimentally investigated candidate molecules comprised of chiral camphorquinone derivatives by measuring the scalar invariant associated with the rank two pseudotensor using hyper-Rayleigh scattering. We have found sizable scalar figures of merit for several compounds using light for which the second harmonic wavelengths are greater than 100 nm longer than the absorption peak location. At these wavelengths, the quadrupolar scalar is as large as the polar (EFISH) scalar of p-nitroaniline. Prospects for applications are discussed.

Electromagnetic (EM) methods, long used for borehole logging as a formation evaluation tool in developed oil fields, are rarely applied in surface or crosshole configurations or applied in cased wells. This is largely due to the high levels of cultural noise and the preponderance of steel well casing. However, recent experimental success with crosshole EM systems for water and steam flood monitoring using fiberglass cased wells has shown promise in applying these techniques to development and production (D & P) problems. This paper describes technological solutions that will allow for successful application of EM techniques in oil fields, despite surface noise and steel casing. First an example sites the application of long offset logging to map resistivity structure away from the borehole. Next, a successful application of crosshole EM where one of the wells is steel cased is described. The potential application of earth`s field nuclear magnetic resonance (NMR) to map fluid saturation at large distances from the boreholes is also discussed.

A fundamental understanding of aging in an organic material requires that one understand how aging affects the chemical structure of a material, and how these chemical changes are related to the material`s macroscopic properties. This level of understanding is usually achieved by examining the material on a variety of length scales ranging from atomic to meso-scale to macroscopic. The authors are developing and applying several {sup 13}C nuclear magnetic resonance (NMR) spectroscopy experiments to characterize the aging process of organic materials over a broad range of length scales. Examples of studies which range from atomic to macroscopic will be presented.

Errors in model parameters, sensing, and control are inevitably present in real robot systems. These errors must be considered in order to automatically plan robust solutions to many manipulation tasks. Lozano-Perez, Mason, and Taylor proposed a formal method for synthesizing robust actions in the presence of uncertainty; this method has been extended by several subsequent researchers. All of these results presume the existence of worst-case error bounds that describe the maximum possible deviation between the robot`s model of the world and reality. This paper examines the problem of measuring these error bounds for a real robot workcell. These measurements are difficult, because of the desire to completely contain all possible deviations while avoiding bounds that are overly conservative. The authors present a detailed description of a series of experiments that characterize and quantify the possible errors in visual sensing and motion control for a robot workcell equipped with standard industrial robot hardware. In addition to providing a means for measuring these specific errors, these experiments shed light on the general problem of measuring worst-case errors.

Multicrystalline-silicon (mc-Si) materials and cells feature large areal variations in material and junction quality. The regions with poor device quality have been predicted to have more recombination current at forward bias than a simple area-weighted average due to the parallel interconnection of the good and bad regions by the front junction. The authors have examined the effect of gettering on areal inhomogeneities in large-area mc-Si cells. Cells with large areal inhomogeneities were found to have increased non-ideal recombination current, which is in line with theoretical predictions. Phosphorus-diffusion and aluminum-alloy gettering of mc-Si was found to reduce the areal inhomogeneities and improve large-area mc-Si device performance.

Inductively coupled plasma etching of GaN, AlN, InN, InGaN and InAlN was investigated in CH{sub 4}/H{sub 2}/Ar plasmas as a function of dc bias, and ICP power. The etch rates were generally quite low, as is common for III-nitrides in CH{sub 4} based chemistries. The etch rates increased with increasing dc bias. At low rf power (150 W), the etch rates increased with increasing ICP power, while at 350 W rf power, a peak was found between 500 and 750 W ICP power. The etched surfaces were found to be smooth, while selectivities of etch were {le} 6 for InN over GaN, AlN, InGaN and InAlN under all conditions.

Gas guns and velocity interferometric techniques have been used to determine the loading behavior of an AD995 alumina rod 19 mm in diameter by 75 mm and 150 mm long, respectively. Graded-density materials were used to impact both bare and sleeved alumina rods while the velocity interferometer was used to monitor the axial-velocity of the free end of the rods. Results of these experiments demonstrate that (1) a time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod, and (2) the intermediate loading rates obtained in this configuration lie between split Hopkinson bar and shock-loading techniques.

The B61 accelerated aging unit (AAU) provided a unique opportunity to document the effects of a controlled, long-term thermal cycling environment on the aging of materials used in the device. This experiment was of particular interest to solder technologists because thermal cycling environments are a predominant source of solder joint failures in electronic assemblies. Observations of through hole solder joints in the MC2918 Firing Set from the B61 AAU did not reveal signs of catastrophic failure. Quantitative analyses of the microstructural metrics of intermetallic compound layer thickness and Pb-rich phase particle distributions indicated solder joint aging that was commensurate with the accelerated aging environment. The effects of stress-enhanced coarsening of the Pb-rich phase were also documented.

Passive autocatalytic recombiners (PARs) are being considered by the nuclear power industry as a combustible gas control system in operating plants and advanced light water reactor (ALWR) containments for design basis events. Sandia National Laboratories (SNL) has developed systems and methodologies to measure the amount of hydrogen that can be depleted in a containment by a PAR. Experiments were performed that determined the hydrogen depletion rate of a PAR in the presence of steam and also evaluated the effect of scale (number of cartridges) on the PAR performance at both low and high hydrogen concentrations.

The US Department of Energy has recently completed a topical safety analysis report outlining the design and operation of a Centralized Interim Storage Facility for spent commercial nuclear fuel. During the course of the design, dose assessments indicated the need for remote operation of many of the cask handling operations. Use of robotic equipment was identified as a desirable handling solution that is capable of automating many of the operations to maintain throughput, and sufficiently flexible to handle five or more different storage cask designs in varying numbers on a given day. This paper discusses the facility and the dose assessment leading to this choice, and reviews factors to be considered when choosing robotics or automation. Further, a new computer simulation tool to quantify dose to humans working in radiological environments, the Radiological Environment Modeling System (REMS), is introduced. REMS has been developed to produce a more accurate estimate of dose to radiation workers in new activities with radiological hazards.

This document describes a Software Development Methodology for High Consequence Systems. A High Consequence System is a system whose failure could lead to serious injury, loss of life, destruction of valuable resources, unauthorized use, damaged reputation or loss of credibility or compromise of protected information. This methodology can be scaled for use in projects of any size and complexity and does not prescribe any specific software engineering technology. Tasks are described that ensure software is developed in a controlled environment. The effort needed to complete the tasks will vary according to the size, complexity, and risks of the project. The emphasis of this methodology is on obtaining the desired attributes for each individual High Consequence System.

Vector network analyzers are a convenient way to measure scattering parameters of a variety of microwave devices. However, these instruments, unlike oscilloscopes for example, require a relatively high degree of user knowledge and expertise. Due to the complexity of the instrument and of the calibration process, there are many ways in which an incorrect measurement may be produced. The Microwave Project, which is part of SNL`s Primary Standards laboratory, routinely uses check standards to verify that the network analyzer is operating properly. In the past, these measurements were recorded manually and, sometimes, interpretation of the results was problematic. To aid the measurement assurance process, a software program was developed to automatically measure a check standard and compare the new measurements with a historical database of measurements of the same device. The program acquires new measurement data from selected check standards, plots the new data against the mean and standard deviation of prior data for the same check standard, and updates the database files for the check standard. The program is entirely menu-driven requiring little additional work by the user. This report describes the function of the software, including a discussion of its capabilities, and the way in which the software is used in the lab.

Three Milliwatt Generator Heat Source (MWGHS) shelf-life-related capsules were pressure-burst tested after thermal aging. Shelf-life capsules PB-08-03 (MC2893) and MPT-11-33 (MC3599) were tested at 1,010 C and capsule PB-07-13 (MC2893) was tested at 1,100 C. Subsequent to pressure-burst testing, each capsule was bubble-leak tested then metallographically examined. Post-mortem evaluation consisted of metallography, microhardness, scanning electron microscopy (SEM), and oxygen and nitrogen analysis. Capsules PB-08-03 and PB-07-13 failed by elevated temperature stress-rupture in the coarse-grained cap to body welds, as has been documented for previous capsules. Pressure-burst testing of capsule MPT-11-33 was terminated prior to failure after 739 hours on test at 1,010 C, however, microscopic examination of the weld indicated that similar failure had began to occur in the interior portion of the capsule to body weld. Evidence was obtained indicating that metallurgical changes occurred during the pressure-burst test performed at 1,100 C. The metallurgical observations of a preferred site for elevated temperature deformation and fracture (the coarse-grained weld region) and structural instability (the property changes during testing at 1,100 C) need to be considered in component lifetime prediction and modeling efforts.

This paper briefly describes a prototype sensor for detecting land mines placed in shallow water. An automatic system was developed which incorporates chemical concentration technology, an ion mobility spectrometer, and control and fluid movement subsystems. The system design was successfully demonstrated using laboratory instruments and equipment. Components for the portable unit, which will weigh less than 20 pounds, have been fabricated; field demonstrations will be completed by spring 1998. 4 figs.

This paper discusses recent experiments in the manipulation and assembly of parts with 100 micron outside dimensions and submicron tolerances. The objective of this work is to develop a micromanipulation workcell which can automatically assemble LIGA (Lithography Galvonoforming Abforming) parts using an assembly plan and a CAD drawing of each of the components. The workcell consists of an AdeptOne robot, precision stages, long distance microscope, and a high aspect ratio modeled polysilicon tweezers for picking up the parts. Fourier optics methods are used to generate synthetic microscope images from CAD drawings. These synthetic images are used off-line to test image processing routines under varying magnifications an depths of field. They also provide reference image features which are used to visually servo the true part to the desired position.

Designers of components-based, real-time systems need to guarantee to correctness of soft-ware and its output. Complexity of a system, and thus the propensity for error, is best characterized by the number of states a component can encounter. In many cases, large numbers of states arise where the processing is highly dependent on context. In these cases, states are often missed, leading to errors. The following are proposals for compactly specifying system states which allow the factoring of complex components into a control module and a semantic processing module. Further, the need for methods that allow for the explicit representation of ambiguity and uncertainty in the design of components is discussed. Presented herein are examples of real-world problems which are highly context-sensitive or are inherently ambiguous.

Photovoltaic (PV) modules that provide only ac power give new dimensions to the use of, and utility interface of, PV systems because all of the dc issues are virtually eliminated. These AC PV modules offer the important advantage that customers may now purchase a PV system without hiring a design engineer. A qualified electrician will be able to install a complete PV system that performs as expected and meets local electrical codes. Simple installations of additional AC PV modules will be possible once the proper branch circuit wiring and protection have been installed. Codes and standards are currently being written to address the utility-interconnect issues for AC PV modules and other interactive inverters. An industry-supported Task Group has recently written and submitted proposals for changes to bring Article 690 of the 1999 National Electrical Code{reg_sign} (NEC{reg_sign}) up to the state-of-the-art for PV devices such as AC PV modules. This paper summarizes the proposed code changes and standards related to the evolving AC PV module technology in the United States. Topics such as the need for dedicated branch circuits for AC PV modules in residential applications are discussed and analyzed. Requirements for limiting the number of AC modules on a branch circuit and the listing requirements that make safe installations are discussed. Coordination of all standards activities for AC module installations, the building-integrated perspectives, and utility-interface issues is discussed.

The U.S. National Photovoltaic Program began in 1975 by supporting the development of terrestrial PV modules and hardware associated with grid-connected PV systems. Early PV-system demonstration programs were also supported and cost shared by the U.S. Department of Energy (DOE). A wide variety of PV systems were deployed, usually with utility participation. The early demonstration projects provided, and continue to provide, valuable PV system experience to utilities, designers and suppliers. As a result of experience gained, several important milestones in codes and standards pertaining to the design, installation and operation of photovoltaic (PV) systems have been completed. These code and standard activities were conducted through collaboration of participants from all sectors of the PV industry, utilities and the US DOE National Photovoltaic Program. Codes and standards that have been proposed, written, or modified include changes and additions for the 1999 National Electric Code{reg_sign} (NEC{reg_sign}), standards for fire and personnel safety, system testing, field acceptance, component qualification, and utility interconnection. Project authorization requests with the Institute of Electrical and Electronic Engineers (IEEE) have resulted in standards for component qualification and were further adapted for standards used to list PV modules and balance-of-system components. Industry collaboration with Underwriter Laboratories, Inc., with the American Society for Testing and Materials, and through critical input and review for international standards with the International Electrotechnical Commission have resulted in new and revised domestic and international standards for PV applications. Activities related to work on codes and standards through the International Energy Agency are also being supported by the PV industry and the US DOE. The paper shows relationships between activities in standards writing.

A new method to analyze human errors has been demonstrated at a pressurized water reactor (PWR) nuclear power plant. This was the first application of the new method referred to as A Technique for Human Error Analysis (ATHEANA). The main goals of the demonstration were to test the ATHEANA process as described in the frame-of-reference manual and the implementation guideline, test a training package developed for the method, test the hypothesis that plant operators and trainers have significant insight into the error-forcing-contexts (EFCs) that can make unsafe actions (UAs) more likely, and to identify ways to improve the method and its documentation. A set of criteria to evaluate the {open_quotes}success{close_quotes} of the ATHEANA method as used in the demonstration was identified. A human reliability analysis (HRA) team was formed that consisted of an expert in probabilistic risk assessment (PRA) with some background in HRA (not ATHEANA) and four personnel from the nuclear power plant. Personnel from the plant included two individuals from their PRA staff and two individuals from their training staff. Both individuals from training are currently licensed operators and one of them was a senior reactor operator {open_quotes}on shift{close_quotes} until a few months before the demonstration. The demonstration was conducted over a 5 month period and was observed by members of the Nuclear Regulatory Commission`s ATHEANA development team, who also served as consultants to the HRA team when necessary. Example results of the demonstration to date, including identified human failure events (HFEs), UAs, and EFCs are discussed. Also addressed is how simulator exercises are used in the ATHEANA demonstration project.

Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia`s Monitoring Systems and Technology Center and has been funded by the US Department of Energy`s Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, top-level, modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM`s unique features is that it integrates results from the various CTBT sensor technologies (seismic, infrasound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection) and location accuracy of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system`s performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. This report describes version 1.2 of IVSEM.

The use of computational modeling to improve equipment and process designs for chemical vapor deposition (CVD) reactors is becoming increasingly common. Commercial codes are available that facilitate the modeling of chemically-reacting flows, but chemical reaction mechanisms must be separately developed for each system of interest. One f the products of the Watkins-Johnson Company (WJ) is a reactor marketed to semiconductor manufacturers for the atmospheric-pressure chemical vapor deposition (APCVD) of silicon oxide films. In this process, TEOS (tetraethoxysilane, Si(OC{sub 2}H{sub 5}){sub 4}) and ozone (O{sub 3}) are injected (in nitrogen and oxygen carrier gases) over hot silicon wafers that are being carried through the system on a moving belt. As part of their equipment improvement process, WJ is developing computational models of this tool. In this effort, they are collaborating with Sandia National Laboratories (SNL) to draw on Sandia`s experience base in understanding and modeling the chemistry of CVD processes.

Self Assembled (SA) thin films and Langmuir-Blodgett (LB) thin films are emerging technologies for the development of chemical and bio-chemical sensors, electrooptic films, second harmonic generators (frequency doublers), templates for biomimetic growth etc. One of the goals of this project was to extend Sandia`s characterization techniques and molecular modeling capabilities for these complex two-dimensional geometries with the objective of improving the control of the fabrication of these structures for specific applications. Achieving this requires understanding both the structure throughout the thickness of the films and the in-plane lattice of the amphiphilic molecules. To meet these objectives they used atomic force microscopy (AFM), X-ray reflectivity, and molecular modeling. While developing these capabilities, three different materials systems were fabricated and characterized: (1) Self Assembled Monolayers (SAMs) of octadecyltrichlorosilane (OTS) and LB films of arachidic acid on silicon wafers; (2) SAMs on PZT substrates; and (3) electrochemical deposition of CdS on LB film templates.

This report addresses the need for government sponsored R and D to address real public problems. The motivation is that a public benefit of the money spent must be demonstrated. The areas identified as not having appropriate attention resulting in unmet public needs include healthcare cost, cost and benefits of regulations, infrastructure problems, defense spending misaligned with foreign policy objectives, the crime problem, energy impact on the environment, the education problem, low productivity growth industry sectors, the income distribution problem, the aging problem, the propagation of disease and policy changes needed to address the solution of these problems.

The goal of this project was to develop a novel technology that may be used to eventually manufacture a new generation of inorganic membranes and sensors with oriented, unidirectional monosized pores. The premise is that very thin membranes with oriented channels as pores will have a high flux in addition to being highly selective. Applications include: (1) gas separation membranes for oxygen enrichment, partial oxidation, dehydrogenation, and purification of natural gas; (2) refractory catalytic membrane reactors; and (3) molecular recognition sensors. The methodology for making such membranes was to combine Langmuir - Blodgett (LB) technology with sol-gel chemistry to engineer pore channels within the range 3 to 20 K The channel structure was fabricated of amorphous SiO{sub 2} because of its good thermal, chemical, and mechanical stability. Our approach was to use LB techniques to uniformly place organic molecular spacers throughout a thin silica precursor matrix and apply this film to a substrate. LB films of solid solutions of commercially available silane amphiphiles and organic amphiphiles were fabricated. The siloxane groups were then hydrolyzed to form silica and the organic portions of the amphiphiles removed by thermal decomposition. With the completely fugitive organic spacer amphiphiles removed, a thin silica film with micropores resulted. The pore size was in the range of 6 - 8 {angstrom} and in an ultra-thin configuration. With further development this technique may be useful for fabrication of inorganic membranes which satisfy all the criteria of the ideal membrane.

Nuclear power plants are converting to digital instrumentation and control systems; however, the effects of abnormal environments such as fire and smoke on such systems are not known. There are no standard tests for smoke, but previous smoke exposure tests at Sandia National Laboratories have shown that digital communications can be temporarily interrupted during a smoke exposure. Another concern is the long-term corrosion of metals exposed to the acidic gases produced by a cable fire. This report documents measurements of basic functional circuits during and up to 1 day after exposure to smoke created by burning cable insulation. Printed wiring boards were exposed to the smoke in an enclosed chamber for 1 hour. For high-resistance circuits, the smoke lowered the resistance of the surface of the board and caused the circuits to short during the exposure. These circuits recovered after the smoke was vented. For low-resistance circuits, the smoke caused their resistance to increase slightly. A polyurethane conformal coating substantially reduced the effects of smoke. A high-speed digital circuit was unaffected. A second experiment on different logic chip technologies showed that the critical shunt resistance that would cause failure was dependent on the chip technology and that the components used in the smoke exposures were some of the most smoke tolerant. The smoke densities in these tests were high enough to cause changes in high impedance (resistance) circuits during exposure, but did not affect most of the other circuits. Conformal coatings and the characteristics of chip technologies should be considered when designing circuitry for nuclear power plant safety systems, which must be highly reliable under a variety of operating and accident conditions. 10 refs., 34 figs., 18 tabs.

A message-passing version of the PAGOSA shock-wave physics code has been developed at Sandia National Laboratories for multiple-instruction, multiple-data stream (MIMD) computers. PAGOSA is an explicit, Eulerian code for modeling the three-dimensional, high-speed hydrodynamic flow of fluids and the dynamic deformation of solids under high rates of strain. It was originally developed at Los Alamos National Laboratory for the single-instruction, multiple-data (SIMD) Connection Machine parallel computers. The performance of Sandia`s message-passing version of PAGOSA has been measured on two MIMD machines, the nCUBE 2 and the Intel Paragon XP/S. No special efforts were made to optimize the code for either machine. The measured scaled speedup (computational time for a single computational node divided by the computational time per node for fixed computational load) and grind time (computational time per cell per time step) show that the MIMD PAGOSA code scales linearly with the number of computational nodes used on a variety of problems, including the simulation of shaped-charge jets perforating an oil well casing. Scaled parallel efficiencies for MIMD PAGOSA are greater than 0.70 when the available memory per node is filled (or nearly filled) on hundreds to a thousand or more computational nodes on these two machines, indicating that the code scales very well. Thus good parallel performance can be achieved for complex and realistic applications when they are first implemented on MIMD parallel computers.

A contact enforcement algorithm has been developed for matrix-free quasistatic finite element techniques. Matrix-free (iterative) solution algorithms such as nonlinear Conjugate Gradients (CG) and Dynamic Relaxation (DR) are distinctive in that the number of iterations required for convergence is typically of the same order as the number of degrees of freedom of the model. From iteration to iteration the contact normal and tangential forces vary significantly making contact constraint satisfaction tenuous. Furthermore, global determination and enforcement of the contact constraints every iteration could be questioned on the grounds of efficiency. This work addresses this situation by introducing an intermediate iteration for treating the active gap constraint and at the same time exactly (kinematically) enforcing the linearized gap rate constraint for both frictionless and frictional response.

The aim of this project was to develop the capabilities for Sandia to fabricate self assembled Langmuir-Blodgett (LB) films of various materials and to exploit their two-dimensional crystalline structure to promote the growth of oriented thin films of inorganic materials at room temperature. This includes the design and synthesis of Langmuir-active (amphiphilic) organic molecules with end groups offering high nucleation potential for various ceramics. A longer range goal is that of understanding the underlying principles, making it feasible to use the techniques presented in this report to fabricate unique oriented films of various materials for electronic, sensor, and membrane applications. Therefore, whenever possible, work completed in this report was completed with the intention of addressing the fundamental phenomena underlying the growth of crystalline, inorganic films on template layers of highly organized organic molecules. This problem was inspired by biological processes, which often produce exquisitely engineered structures via templated growth on polymeric layers. Seashells, for example, exhibit great toughness owing to their fine brick-and-mortar structure that results from templated growth of calcium carbonate on top of layers of ordered organic proteins. A key goal in this work, therefore, is to demonstrate a positive correlation between the order and orientation of the template layer and that of the crystalline ceramic material grown upon it. The work completed was comprised of several parallel efforts that encompassed the entire spectrum of biomimetic growth from solution. Studies were completed on seashells and the mechanisms of growth for calcium carbonate. Studies were completed on the characterization of LB films and the capability developed for the in-house fabrication of these films. Standard films of fatty acids were studied as well as novel polypeptides and porphyrins that were synthesized.

Three relatively simple mathematical models have been developed to estimate minimum reactor and radiation shield masses for liquid-metal-cooled reactors (LMRs), in-core thermionic fuel element (TFE) reactors, and out-of-core thermionic reactors (OTRs). The approach was based on much of the methodology developed for the Reactor/Shield Mass (RSMASS) model. Like the original RSMASS models, the new RSMASS-derivative (RSMASS-D) models use a combination of simple equations derived from reactor physics and other fundamental considerations, along with tabulations of data from more detailed neutron and gamma transport theory computations. All three models vary basic design parameters within a range specified by the user to achieve a parameter choice that yields a minimum mass for the power level and operational time of interest. The impact of critical mass, fuel damage, and thermal limitations are accounted for to determine the required fuel mass. The effect of thermionic limitations are also taken into account for the thermionic reactor models. All major reactor component masses are estimated, as well as instrumentation and control (I&C), boom, and safety system masses. A new shield model was developed and incorporated into all three reactor concept models. The new shield model is more accurate and simpler to use than the approach used in the original RSMASS model. The estimated reactor and shield masses agree with the mass predictions from separate detailed calculations within 15 percent for all three models.

In 1967, Sandia National Laboratories published empirical equations to predict penetration into natural earth materials and concrete. Since that time there have been several small changes to the basic equations, and several more additions to the overall technique for predicting penetration into soil, rock, concrete, ice, and frozen soil. The most recent update to the equations was published in 1988, and since that time there have been changes in the equations to better match the expanding data base, especially in concrete penetration. This is a standalone report documenting the latest version of the Young/Sandia penetration equations and related analytical techniques to predict penetration into natural earth materials and concrete. 11 refs., 6 tabs.

This technical report describes some lessons learned from implementing the Message Passing Interface (MPI) standard, and some proposed extentions to MPI, at Sandia. The implementations were developed using Sandia-developed lightweight kernels running on the Intel Paragon and Intel TeraFLOPS platforms. The motivations for this research are discussed, and a detailed analysis of several implementation issues is presented.

The initial National Emission Standards for Hazardous Air Pollutants (NESHAP - 40 CFR 61, Subpart H) Program at Sandia National Laboratories, New Mexico (SNL/NM) required: (1) continuous air monitoring of sources if the calculated effective dose equivalent (EDE) to the maximum exposed individual (MEI) was > 0.1 mrem/yr; (2) the determination of emissions based on measurements or measured parameters if the EDE to the MEI was < 0.1 mrem/yr; and (3) the calculation of worst case releases when the expected air concentrations were below detection limits using standard monitoring equipment. This conservative interpretation of the regulation guided SNL/NM to model, track, and trend virtually all emission sources with the potential to include any radionuclides. The level of effort required to implement these activities was independent of the EDE contributing from individual sources. A recent programmatic review found the NESHAP program to be in excess of the legal requirements. A further review found that, in summation, 13 of 16 radionuclide sources had a negligible impact on the final calculated EDE to the MEI used to demonstrate compliance at 20 separate on-site receptor locations. A reevaluation was performed to meet the legal requirements of 40 CFR 61, Subpart H, and still be reasonable and appropriate under the existing circumstances.

Questions have arisen regarding the applicability of seismic sensors to detect mining (re-entry) with a tunnel boring machine (TBM). Unlike cut and blast techniques of mining which produce impulsive seismic signals, the TBM produces seismic signals which are of long duration. (There are well established techniques available for detecting and locating the sources of the impulsive signals.) The Yucca Mountain repository offered an opportunity to perform field evaluations of the capabilities of seismic sensors because during much of 1996, mining there was progressing with the use of a TBM. During the mining of the repository`s southern branch, an effort was designed to evaluate whether the TBM could be detected, identified and located using seismic sensors. Three data acquisition stations were established in the Yucca Mountain area to monitor the TBM activity. A ratio of short term average to long term average algorithm was developed for use in detection based on the characteristics shown in the time series. For location of the source of detected signals, FK analysis was used on the array data to estimate back azimuths. The back azimuth from the 3 component system was estimated from the horizontal components. Unique features in the timing of the seismic signal were used to identify the source as the TBM.

In this paper, the major elements of the site selection and characterization processes used in the US high level waste program are discussed. While much of the evolution of the site selection and characterization processes have been driven by the unique nature of the US program, these processes, which are well defined and documented, could be used as an initial basis for developing site screening, selection, and characterization programs in other countries. Thus, this paper focuses more on the process elements than the specific details of the US program.

In this paper the authors report on the direct bonding of compound semiconductors and silicon annealed at low temperatures (400 C) using hydrogen and nitrogen. Pressure and temperature relationships on interface characteristics were investigated with high resolution transmission electron microscopy and energy dispersive x-ray spectroscopy. It was found that no morphology differences existed between hydrogen and nitrogen annealed samples. applying the N{sub 2} bonding process, 850nm bottom emitting vertical cavity surface emitting lasers (VCSELs), were bonded to a transparent AlGaAs substrate. Finally, high anneal temperatures (up to 450 C) and shear stress values (> 1.6 MPa) were obtained for GaAs bonded to Si using a dry (plasma) activation technique.

CONTAIN is a reactor accident simulation code developed by Sandia National Laboratories under US Nuclear Regulatory Commission (USNRC) sponsorship to provide integrated analysis of containment phenomena, including those related to nuclear reactor containment loads and radiological source terms. The recently released CONTAIN 2.0 code version represents a significant advance in CONTAIN modeling capabilities over the last major code release (CONTAIN 1.12V). The new modeling capabilities are discussed here. The principal motivation for many of the recent model improvements has been to allow CONTAIN to model the special features in advanced light water reactor (ALWR) designs. The work done in this area is also summarized. In addition to the ALWR work, the USNRC is currently engaged in an effort to qualify CONTAIN for more general use in licensing, with the intent of supplementing or possibly replacing traditional licensing codes. To qualify the CONTAIN code for licensing applications, studies utilizing CONTAIN 2.0 are in progress. A number of results from this effort are presented in this paper to illustrate the code capabilities. In particular, CONTAIN calculations of the NUPEC M-8-1 and ISP-23 experiments and CVTR test {number_sign}3 are presented to illustrate (1) the ability of CONTAIN to model non-uniform gas density and/or temperature distributions, and (2) the relationship between such gas distributions and containment loads. CONTAIN and CONTEMPT predictions for a large break loss of coolant accident scenario in the San Onofre plant are also compared.

Radiation and Nuclear Safety Authority (STUK), Helsinki, Finland and Sandia National Laboratories (SNL), working under the Finnish Support Program to IAEA Safeguards and the United States Department of Energy (DOE) funded International Remote Monitoring Program (Task FIN E 935), have undertaken a joint effort to demonstrate the use of remote monitoring for environmental air sampling and safeguards applications. The results of the task will be used by the IAEA to identify the feasibility, cost-effectiveness, reliability, advantages, and problems associated with remote environmental monitoring. An essential prerequisite for a reliable remote air sampling system is the protection of samples against tampering. Means must be developed to guarantee that the sampling itself has been performed as designed and the original samples are not substituted with samples produced with other equipment at another site. One such method is to label the samples with an unequivocal tag. In addition, the inspection personnel must have the capability to remotely monitor and access the automated environmental air sampling system through the use of various sensors and video imagery equipment. A unique aspect to this project is the network integration of remote monitoring equipment with a STUK radiation monitoring system. This integration will allow inspectors to remotely view air sampler radiation data and sensor/image data through separate software applications on the same review station. A sensor network and video system will be integrated with the SNL developed Modular Integrated Monitoring System (MIMS) to provide a comprehensive remote monitoring approach for safeguards purposes. This field trial system is being implemented through a multiphase approach for use by STUK, SNL, and for possible future use by the IAEA.

The present paper addresses the question: ``What are the general classes of uncertainty and error sources in complex, computational simulations?`` This is the first step of a two step process to develop a general methodology for quantitatively estimating the global modeling and simulation uncertainty in computational modeling and simulation. The second step is to develop a general mathematical procedure for representing, combining and propagating all of the individual sources through the simulation. The authors develop a comprehensive view of the general phases of modeling and simulation. The phases proposed are: conceptual modeling of the physical system, mathematical modeling of the system, discretization of the mathematical model, computer programming of the discrete model, numerical solution of the model, and interpretation of the results. This new view is built upon combining phases recognized in the disciplines of operations research and numerical solution methods for partial differential equations. The characteristics and activities of each of these phases is discussed in general, but examples are given for the fields of computational fluid dynamics and heat transfer. They argue that a clear distinction should be made between uncertainty and error that can arise in each of these phases. The present definitions for uncertainty and error are inadequate and. therefore, they propose comprehensive definitions for these terms. Specific classes of uncertainty and error sources are then defined that can occur in each phase of modeling and simulation. The numerical sources of error considered apply regardless of whether the discretization procedure is based on finite elements, finite volumes, or finite differences. To better explain the broad types of sources of uncertainty and error, and the utility of their categorization, they discuss a coupled-physics example simulation.

Tritium retention and removal are critical issues for the success of ITER or any DT fusion reactor. The Tokamak Fusion Test Reactor, TFTR, is the first fusion facility to afford the opportunity to study the tritium retention and removal over an extended period. In TFTR, tritium accumulates on all surfaces with line of sight to the plasma by codeposition of tritium with carbon. Measurements of both deuterium and tritium retention fractions have yielded retention between 0.2 and 0.6 of the injected fuel in the torus. Tritium has been successfully removed from TFTR by glow discharge cleaning and by air purges. The in-vessel inventory was reduced by a factor of 2, facilitating machine maintenance. In TFTR, the amount of dust recovered from the TFTR vacuum vessel has varied from several grams to a few kilograms.

The primary purpose of this LDRD was to identify and optimize materials as solid acid catalysts for the replacement of environmentally hazardous liquid acids such as H{sub 2}SO{sub 4} and HF which are used as catalysts in both the petroleum and chemical industries. Liquid acids have significant safety, environmental and engineering difficulties associated with their use in process chemistry. Special equipment/materials need to be used with liquid acids. Hydrofluoric acid poses unique safety problems due to it insipid attack on skin and tissue as well as its tendency to plume and travel long distances as a plume when it is released in the atmosphere. Therefore, any time a solid acid catalyst can be used to replace a liquid acid in a processes step, significant environmental, safety, and financial gains can be realized. The majority of work in this LDRD was performed on novel mixed metal phosphates which are a new solid acid catalyst material. Primarily the model reaction, 2-methyl-2-pentene isomerization, was used to determine acidity. These materials were tested for their activity, their deactivation and their stability. In addition, some of the phosphate materials were synthesized using templates in order to try to form a three dimensional network material from these phosphates. The amorphous sulfated zirconium-titanium phosphates were more acidic, as measured by olefin isomerization, than sulfated zirconia. However, they showed some of the same failings as sulfated zirconia in that they deactivated quickly and lost sulfur in a reducing atmosphere. Certain of the mixed metal phosphates, particularly tantalum-containing phosphates, showed strong acidity compared to sulfated zirconia as measured by olefin isomerization reaction.

No abstract available.

Two field tests of the surface area modulation (SAM) downhole wireless telemetry system were performed at the DOE Rocky Mountain Oilfield Testing Center near Casper, Wyoming in November, 1995 and September, 1996. SAM telemetry involves the introduction of a gap of electrically insulating material in the tubular conductors in the well. The electrical resistance of a switch in this gap can then be modulated to alter the electrical characteristics of a circuit involving the well tubulars. These changes affect the current in the circuit, which is monitored with a surface ammeter. Downhole data are encoded and transmitted to the surface as a pattern of current oscillations. The tests successfully demonstrated the ability of the system to transmit information from depths exceeding 2,000 feet to the surface at up to 2,400 baud.

No abstract available.

The goal of the 6th International Meshing Roundtable is to bring together researchers and developers from industry, academia, and government labs in a stimulating, open environment for the exchange of technical information related to the meshing process. In the pas~ the Roundtable has enjoyed significant participation born each of these groups from a wide variety of countries. The Roundtable will consist of technical presentations from contributed papers and abstracts, two invited speakers, and two invited panels of experts discussing topics related to the development and use of automatic mesh generation tools. In addition, this year we will feature a "Bring Your Best Mesh" competition and poster session to encourage discussion and participation from a wide variety of mesh generation tool users. The schedule and evening social events are designed to provide numerous opportunities for informal dialog. A proceedings will be published by Sandia National Laboratories and distributed at the Roundtable. In addition, papers of exceptionally high quaIity will be submitted to a special issue of the International Journal of Computational Geometry and Applications. Papers and one page abstracts were sought that present original results on the meshing process. Potential topics include but are got limited to: Unstructured triangular and tetrahedral mesh generation Unstructured quadrilateral and hexahedral mesh generation Automated blocking and structured mesh generation Mixed element meshing Surface mesh generation Geometry decomposition and clean-up techniques Geometry modification techniques related to meshing Adaptive mesh refinement and mesh quality control Mesh visualization Special purpose meshing algorithms for particular applications Theoretical or novel ideas with practical potential Technical presentations from industrial researchers.

Applications where O-rings are used to isolate atmospheric environments within a structure are critical to weapon reliability. Failure occurs when gases are able to travel from one side of the O-ring to the other. The anticipated cause of failure is the relaxation of the rubber over decades, the reduction in closure force, and the O-ring`s consequent inability to offer a barrier to gas transport. A predictive model with tractable complexity has been developed to predict the time over which an O-ring is able to maintain an acceptable value of closure force.

Sandia National Laboratories is developing a new technology to fabricate three-dimensional metallic components directly from CAD solid models. This process, called Laser Engineered Net Shaping (LENS{trademark}), exhibits enormous potential to revolutionize the way in which metal parts, such as complex prototypes, tooling, and small lot production parts, are produced. To perform the process, metal powder is injected into a molten pool created by a focused, high powered laser beam. Simultaneously, the substrate on which the deposition is occurring is scanned under the beam/powder interaction zone to fabricate the desired cross-sectional geometry. Consecutive layers are sequentially deposited, thereby producing a three-dimensional metal component.

Present and future space-based applications such as sensors, low-weight and low-power data links for satellites, communication between electromagnetically-shielded modules, and short-distance cross-links within satellite constellations may benefit from the inclusion of small, low-power, and high-efficiency lasers such as the recently-developed Vertical Cavity Surface-Emitting Laser (VCSEL). Many factors influence the application of these devices to space. Temperature response, operational lifetime and reliability, and power consumption are all important considerations for space applications. In addition, the space radiation environments must be considered. In this work, the effects of ionizing radiation on VCSELs are studied with an emphasis on proton damage, and with comparisons to related neutron and gamma-induced phenomena. The influence of proton irradiation is studied in-depth for selected VCSEL structures by the use of an ion microbeam. The experiments indicate that VCSELs exhibit much less threshold current shift for a given radiation dose, compared to the more traditional edge-emitting semiconductor lasers, but that self-heating is a more important consideration for VCSELs. The high current densities associated with VCSELs also lead to a strong influence from forward-bias annealing. These effects are common to various VCSEL types (780 nm and 850 nm) and their magnitude at a given dose is strongly dependent on device size. This indicates that, while VCSELs appear to be very insensitive to ionizing radiation when compared with alternative technologies, there are a number of factors that must be taken into account when optimizing for the space environment.

The number of commercial airframes exceeding twenty years of service continues to grow. In addition, Service Life Extension Programs are attempting to extend the {open_quotes}economic{close_quotes} service life of commercial airframes to thirty years. The use of bonded composites may offer the airframe manufacturers and aircraft maintenance facilities a cost effective method to extend the lives of their aircraft. The Federal Aviation Administration Assurance NDI Validation Center (AANC) to validate the use of bonded composite doublers on commercial aircraft.

For elastomers that will be used in applications involving long lifetimes, it is often necessary to first carry out and model accelerated aging experiments at higher than ambient temperatures, and then extrapolate the results in order to make lifetime predictions at the use temperature. Continuing goals in such endeavors are to better understand potential problems with such modeling approaches and to find ways of improving confidence in the predictions when the data are extrapolated. In this paper we will address several important issues involved in these procedures for elastomers exposed to air (oxygen), and discuss some potentially useful techniques and approaches which can increase confidence in lifetime predictions.

The technology developed in this project uses biometric information printed on the document and public key cryptography to ensure that an adversary cannot issue identification documents to unauthorized individuals or alter existing documents to allow their use by unauthorized individuals. This process can be used to produce many types of identification documents with much higher security than any currently in use. The system is demonstrated using a security badge as an example. This project focused on the technologies requiring development in order to make the approach viable with existing badge printing and laminating technologies. By far the most difficult was the image processing required to verify that the picture on the badge had not been altered. Another area that required considerable work was the high density printed data storage required to get sufficient data on the badge for verification of the picture. The image processing process was successfully tested, and recommendations are included to refine the badge system to ensure high reliability. A two dimensional data array suitable for printing the required data on the badge was proposed, but testing of the readability of the array had to be abandoned due to reallocation of the budgeted funds by the LDRD office.

The very general problem of model reduction of nonlinear systems was made tractable by focusing on the very large subclass consisting of linear subsystems connected by nonlinear interfaces. Such problems constitute a large part of the nonlinear structural problems encountered in addressing the Sandia missions. A synthesis approach to this class of problems was developed consisting of: detailed modeling of the interface mechanics; collapsing the interface simulation results into simple nonlinear interface models; constructing system models by assembling model approximations of the linear subsystems and the nonlinear interface models. These system models, though nonlinear, would have very few degrees of freedom. A paradigm problem, that of machine tool vibration, was selected for application of the reduction approach outlined above. Research results achieved along the way as well as the overall modeling of a specific machine tool have been very encouraging. In order to confirm the interface models resulting from simulation, it was necessary to develop techniques to deduce interface mechanics from experimental data collected from the overall nonlinear structure. A program to develop such techniques was also pursued with good success.

Multivariate calibration methods have been applied extensively to the quantitative analysis of Fourier transform infrared (FT-IR) spectral data. Partial least squares (PLS) methods have become the most widely used multivariate method for quantitative spectroscopic analyses. Most often these methods are limited by model error or the accuracy or precision of the reference methods. However, in some cases, the precision of the quantitative analysis is limited by the noise in the spectroscopic signal. In these situations, the precision of the PLS calibrations and predictions can be improved by the incorporation of weighting in the PLS algorithm. If the spectral noise of the system is known (e.g., in the case of detector-noise-limited cases), then appropriate weighting can be incorporated into the multivariate spectral calibrations and predictions. A weighted PLS (WPLS) algorithm was developed to improve the precision of the analysis in the case of spectral-noise-limited data. This new PLS algorithm was then tested with real and simulated data, and the results compared with the unweighted PLS algorithm. Using near-infrared (NIR) calibration precision when the WPLS algorithm was applied. The best WPLS method improved prediction precision for the analysis of one of the minor components by a factor of nearly 9 relative to the unweighted PLS algorithm.

A laboratory-scale experimental test system for small-scale of shock phenomena has been assembled. This system uses a variety of miniature test platforms in which shock loading is provided by laser-driven flyer impact. Acceptor materials include thin-film explosives and high-density metal foils. Optical access is provided for high-speed optical diagnostics such as optically recording velocity interferometry and single-pulse Raman spectroscopy. The experimental assembly for Raman studies features a common laser source for both flyer generation and excitation of Raman scattering (to achieve high timing precision) and a detection scheme that uses the coupling fiber for the excitation source to collect with high efficiency backscattered Raman light. Preliminary system evaluation experiments indicate that detailed particle velocity studies of the dynamic material properties of high-density metals under short-pulse, high-strain-rate loading can be performed in a miniaturized test configuration. Single-pulse Raman studies on shock compressed thin film explosives also appear feasible if the thickness and grain structure of these films can be tailored to enhance the Raman scattering signal sufficiently. Possible improvements in the experimental design and a number of likely applications of these techniques are also discussed.

The wide gap materials SiC, GaN and to a lesser extent diamond are attracting great interest for high power/high temperature electronics. There are a host of device processing challenges presented by these materials because of their physical and chemical stability, including difficulty in achieving stable, low contact resistances, especially for one conductivity type, absence of convenient wet etch recipes, generally slow dry etch rates, the high temperatures needed for implant activation, control of suitable gate dielectrics and the lack of cheap, large diameter conducting and semi-insulating substrates. The relatively deep ionization levels of some of the common dopants (Mg in GaN; B, Al in SiC; P in diamond) means that carrier densities may be low at room temperature, and thus contact resistances will be greatly improved provided the metallization is stable and reliable. Some recent work with CoSi{sub x} on SiC and W-alloys on GaN show promise for improved ohmic contacts. The issue of unintentional hydrogen passivation of dopants will also be covered - this leads to strong increases in resistivity of p-SiC and GaN, but to large decreases in resistivity of diamond. Recent work on development of wet etches has found recipes for AlN (KOH), while photochemical etching of SiC and GaN has been reported. In the latter cases p-type materials is not etched, which can be a major liability in some devices. The dry etch results obtained with various novel reactors, including ICP, ECR and LE4 will be compared - the high ion densities in the former techniques produce the highest etch rates for strongly-bonded materials, but can lead to preferential loss of N from the nitrides and therefore to a highly conducting surface. This is potentially a major problem for fabrication of dry etched, recessed gate FET structures.

This document is a reference guide for GAETR, Graphical Analysis of Event Trees, a software package developed at Sandia National Laboratories. GAETR may be used as a stand-alone code or as a module in the ARRAMIS{trademark} risk and reliability code suite. GAETR is designed to graphically create event trees and plot SETAC (Sandia Event Tree Analysis Code) output on IBM-compatible personal computers using the Microsoft{reg_sign} Windows{trademark} 95/NT operating environment. This manual explains the fundamentals of creating an event tree, including formatting, saving sequence information, printing, editing, and importing graphics to other software packages.

Experimental results are presented for seven creep experiments on welded specimens of the Paintbrush tuff recovered from borehole USW NRG-7/7A at Yucca Mountain, Nevada. The measurements were performed at differential stresses of 40, 70, 100, and 130 MPa. The confining pressure and temperature for each of the experiments was 10 MPa and 225 {degrees}C respectively. All of the specimens were tested drained, in a room dry condition. All of the experiments were terminated prior to failure. The duration of the experiments range from 2.6 x 10{sup 6} seconds to 5.9 x 10{sup 6} seconds. Creep strain is observed for those specimens tested at a stress difference. The strain rate is not constant. A primary creep stage is observed. Secondary creep does not exhibit a constant strain rate, but decreases with increasing time.

A system for automatic tool path generation was developed at Sandia National Laboratories for finish machining operations. The system consists of a commercially available 5-axis milling machine controlled by Sandia developed software. This system was used to remove overspray on cast turbine blades. A laser-based, structured-light sensor, mounted on a tool holder, is used to collect 3D data points around the surface of the turbine blade. Using the digitized model of the blade, a tool path is generated which will drive a 0.375 inch grinding pin around the tip of the blade. A fuzzified digital filter was developed to properly eliminate false sensor readings caused by burrs, holes and overspray. The digital filter was found to successfully generate the correct tool path for a blade with intentionally scanned holes and defects. The fuzzified filter improved the computation efficiency by a factor of 25. For application to general parts, an adaptive scanning algorithm was developed and presented with simulation and experimental results. A right pyramid and an ellipsoid were scanned successfully with the adaptive algorithm in simulation studies. In actual experiments, a nose cone and a turbine blade were successfully scanned. A complex shaped turbine blade was successfully scanned and finished machined using these algorithms.

This report presents a strategy for delineating the location of residual dense non-aqueous phase liquids (DNAPL) that combines probabilistic simulations of DNAPL spill location and volume, geologic texture constraining migration pathways, migration physics through percolation modeling, and a decision analysis model to pick optimal locations for sampling wells. The authors` strategy is an iterative process of simulating the residual DNAPL location, selecting new locations for data collection, gathering data, and then using the data to condition further simulations of DNAPL migration. As they iterate through this process, data worth analysis is used to determine an appropriate stopping point. The authors present the results from a preliminary version of their model, showing how the process was used to delineate hypothetical DNAPL spills.

Data visualization is an emerging technology with high potential for addressing the information overload problem. This project extends the data visualization work of the Navigating Science project by coupling it with more traditional information retrieval methods. A citation-derived landscape was augmented with documents using a text-based similarity measure to show viability of extension into datasets where citation lists do not exist. Landscapes, showing hills where clusters of similar documents occur, can be navigated, manipulated and queried in this environment. The capabilities of this tool provide users with an intuitive explore-by-navigation method not currently available in today`s retrieval systems.

This report describes the responses of three energetic materials (TNT, RDX, and PETN) to varying reactant ion chemistries and IMS cell temperatures. The following reactant ion chemistries were evaluated; air-dry; air-wet; methylene chloride-dry; methylene chloride-wet; methylene bromide-dry; nitrogen dioxide-wet; sulfur dioxide-wet. The temperature was varied between 160 - 220{degrees}C.

A new approach to the fabrication of porous, amorphous inorganic membranes using organic pore templates was investigated. The pore templates were a new family of hybrid organic-inorganic monomers. As background for membrane work, the monomers were polymerized by sol-gel techniques to make crosslinked polymers. Molecular modeling was used to create computer simulations of the materials and provide insight into their composites, were then converted into porous silicas using low temperature oxygen plasma techniques. A select few of the monomers were copolymerized with silica monomers to form non-porous thin films on mesoporous substrates. The films were converted into porous silica thin films with thermal oxidations and the resulting membranes were tested for gas selectivities and flux.

Sandia National Laboratories is developing a system that uses robots to package pits at Pantex in the AT-400A pit storage and transportation container. This report will give an overview of the AT-400A packaging process, and the parts of the overall AT-400A packaging operation that will be performed robotically. The process employed to move from development in the laboratory at Sandia to production use at Pantex will be described. Finally, important technology components being developed for and incorporated into the robotic system will be described. 7 refs., 9 figs.

In 1973 Mr. W. Athey of the Environmental Protection Agency wrote a computer program called SECPOP which calculated population estimates. Since that time, two things have changed which suggested the need for updating the original program - more recent population censuses and the widespread use of personal computers (PCs). The revised computer program uses the 1990 and 1992 Population Census information and runs on current PCs as {open_quotes}SECPOP90.{close_quotes} SECPOP90 consists of two parts: site and regional. The site provides population and economic data estimates for any location within the continental United States. Siting analysis is relatively fast running. The regional portion assesses site availability for different siting policy decisions; i.e., the impact of available sites given specific population density criteria within the continental United States. Regional analysis is slow. This report compares the SECPOP90 population estimates and the nuclear power reactor licensee-provided information. Although the source, and therefore the accuracy, of the licensee information is unknown, this comparison suggests SECPOP90 makes reasonable estimates. Given the total uncertainty in any current calculation of severe accidents, including the potential offsite consequences, the uncertainty within SECPOP90 population estimates is expected to be insignificant. 12 refs., 55 figs., 7 tabs.

Experimental results are presented for bulk and mechanical properties measurements on specimens of the Paintbrush tuff recovered from the USW NRG-6 and USW NRG-7/7A borehole at Yucca Mountain, Nevada. Measurements have been performed on five thermal/mechanical units: TCw, PTn, TSw2, and TSw3. The following bulk properties are reported for each specimen: dry bulk density, saturated bulk density, average grain density and porosity. Confined compression to failure tests were performed on selected specimens recovered from the boreholes at confining pressures of 5 and 10 MPa. In addition, compressional and shear wave velocities were measured on the specimens prior to testing. Measurements were conducted under drained conditions at room temperature on nominally water saturated specimens. The nominal strain rate for the experiments was 10{sup -5} s{sup -1}.

The major results from SNL`s Conceptual Model Development and Validation Task (WBS 1.2.5.4.6) as developed through exploration of small scale processes were synthesized in Glass et al. to give guidance to Performance Assessment on improving conceptual models for isothermal flow in unsaturated, fractured rock. There, pressure saturation and relative permeability curves for single fractures were proposed to be a function of both fracture orientation within the gravity field and initial conditions. We refer the reader to Glass et al. for a discussion of the implications of this behavior for Performance Assessment. The scientific research we report here substantiates this proposed behavior. We address the modeling of phase structure within fractures under natural gradient conditions relevant to unsaturated flow through fractures. This phase structure underlies the calculation of effective properties for individual fractures and hence fracture networks as required for Performance Assessment. Standard Percolation (SP) and Invasion Percolation (IP) approaches have been recently proposed to model the underlying phase saturation structures within the individual fractures during conditions of two-phase flow. Subsequent analysis of these structures yields effective two-phase pressure-saturation and relative permeability relations for the fracture. However, both of these approaches yield structures that are at odds with physical reality as we see in experiments and thus effective properties calculated from these structures are in error. Here we develop and evaluate a Modified Invasion Percolation (MIP) approach to better model quasi-static immiscible displacement in fractures. The effects of gravity, contact angle, local aperature field geometry, and local in-plane interfacial curvature between phases are included in the calculation of invasion pressure for individual sites in a discretized aperture field.

The purpose of this laboratory-directed research and development (LDRD) project was to develop and assess novel low-permittivity dielectric materials for applications as interlevel dielectrics (ILDs) in Si-based microelectronics. There were three classes of materials investigated: (1) novel covalently-bonded ceramics containing carbon, boron, and/or nitrogen, (2) fluorinated SiO{sub 2} (SiOF), and (3) plasma polymerized fluorocarbon (PPFC). The specific advantages and disadvantages for each potential low k ILD material were evaluated. It was discovered that highly energetic deposition processes are required for the formation of thermally and environmentally stable carbon or boron nitride ceramics, and the resulting films may have many potentially valuable applications, such as diffusion barriers, tribological coatings, micro-sensor materials, etc. The films are not suitable as low k ILDs, however, because the highly energetic deposition process leads to films with high atomic density, and this leads to high dielectric constants. SiOF shows a promise as low k ILD material for near-term applications, but special passivation or encapsulation strategies may be required in order to reduce two instability problems that the authors have discovered: moisture absorption and thermal instability of the SiOF/Al interface. PPFC films offer promise for even lower dielectric constant ILDs than SiOF, but it will be necessary to develop new strategies to passivate the free radicals in the films generated during deposition. These free radicals lead to increase in dielectric loss over time when the films are exposed to room ambient conditions.

The Virtual Collaborative Environment (VCE) and Distributed Collaborative Workbench (DCW) are new technologies that make it possible for diverse users to synthesize and share mechatronic, sensor, and information resources. Using these technologies, university researchers, manufacturers, design firms, and others can directly access and reconfigure systems located throughout the world. The architecture for implementing VCE and DCW has been developed based on the proposed National Information Infrastructure or Information Highway and a tool kit of Sandia-developed software. Further enhancements to the VCE and DCW technologies will facilitate access to other mechatronic resources. This report describes characteristics of VCE and DCW and also includes background information about the evolution of these technologies.

The authors developed and implemented a highly parallel computational algorithm for solution of the inverse scattering problem generated when an integrated circuit is illuminated by laser. The method was used as part of a system to measure diffraction grating line widths on specially fabricated test wafers and the results of the computational analysis were compared with more traditional line-width measurement techniques. The authors found they were able to measure the line width of singly periodic and doubly periodic diffraction gratings (i.e. 2D and 3D gratings respectively) with accuracy comparable to the best available experimental techniques. They demonstrated that their parallel code is highly scalable, achieving a scaled parallel efficiency of 90% or more on typical problems running on 1024 processors. They also made substantial improvements to the algorithmics and their original implementation of Rigorous Coupled Waveform Analysis, the underlying computational technique. These resulted in computational speed-ups of two orders of magnitude in some test problems. By combining these algorithmic improvements with parallelism the authors achieve speedups of between a few thousand and hundreds of thousands over the original engineering code. This made the laser diffraction measurement technique practical.

This report presents a microsimulation model of a transition economy. Transition is defined as the process of moving from a state-enterprise economy to a market economy. The emphasis is on growing a market economy starting from basic microprinciples. The model described in this report extends and modifies the capabilities of Aspen, a new agent-based model that is being developed at Sandia National Laboratories on a massively parallel Paragon computer. Aspen is significantly different from traditional models of the economy. Aspen`s emphasis on disequilibrium growth paths, its analysis based on evolution and emergent behavior rather than on a mechanistic view of society, and its use of learning algorithms to simulate the behavior of some agents rather than an assumption of perfect rationality make this model well-suited for analyzing economic variables of interest from transition economies. Preliminary results from several runs of the model are included.

A Monte Carlo algorithm is used to determine the apparent spatial blurring of a terrestrial 1.07 micron optical point source due to cloud scattering as seen from space. The virtual image of a point source over a virtual source plane area 22.4 x 22.4 square kilometers arising from cloud scattering was determined for stratus clouds (NASA cloud number 5) and altostratus clouds optical source arises from photon scattering by cloud water droplets. Displacement of the virtual source is due to the apparent illumination of the cloud top region directly about the actual source which when viewed at a nonzero look angle gives a projected displacement of the apparent source relative to the actual source. These features are quantified by an analysis of the Monte Carlo computational results.

Unlike silicon microelectronics, photonics packaging has proven to be low yield and expensive. One approach to make photonics packaging practical for low cost applications is the use of {open_quotes}smart{close_quotes} packages. {open_quotes}Smart{close_quotes} in this context means the ability of the package to actuate a mechanical change based on either a measurement taken by the package itself or by an input signal based on an external measurement. One avenue of smart photonics packaging, the use of polysilicon micromechanical devices integrated with photonic waveguides, was investigated in this research (LDRD 3505.340). The integration of optical components with polysilicon surface micromechanical actuation mechanisms shows significant promise for signal switching, fiber alignment, and optical sensing applications. The optical and stress properties of the oxides and nitrides considered for optical waveguides and how they are integrated with micromechanical devices were investigated.

This report describes the design features of series connected photovoltaic arrays which will be required to charge capacitors to relatively high (400V) voltages in time periods on the order of 1 microsecond. The factors which determine the array voltage and the capacitor charge time are given. Individual element junction designs, along with an interconnect scheme, and a semiconductor process to realize them are presented. Finally, the input laser optical required to meet the requirements is determined.

The response of a variety of sucker rod couplings to an applied axial load was simulated using axisymmetric finite element models. The calculations investigated three sucker rod sizes and various combinations of the slimhole, Spiralock, and Flexbar modifications to the coupling. In addition, the effect of various make-ups (assembly tightness) on the performance of coupling was investigated. An axial load was applied to the sucker rod ranging from {minus}5 ksi to 40 ksi, encompassing three load cycles identified on a modified Goodman diagram as acceptable for indefinite service life of the sucker rods. The simulations of the various coupling geometries and make-ups were evaluated with respect to how well they accomplish the two primary objectives of preloading threaded couplings: (1) to lock the threaded coupling together so that it will not loosen and eventually uncouple, and (2) to improve the fatigue resistance of the threaded connection by reducing the stress amplitude in the coupling when subjected to cyclic loading. Perhaps the most significant finding in this study was the characterization of the coupling parameters which affect two stress measures. The mean hydrostatic stress, which determines the permissible effective alternating stress, is a function of the coupling make-up. Whereas, the alternating effective stress is a function of the relative stiffnesses of the pin and box sections of the coupling and, as long as the coupling does not separate, is unaffected by the amount of circumferential displacement applied during make-up. The results of this study suggest approaches for improving the fatigue resistance of sucker rod couplings.

Experimental results are presented for 24 thermal expansion experiments performed on 5 welded specimens of the Paintbrush tuff recovered from borehole USW SD-12 at Yucca Mountain, Nevada. The thermal expansion experiments were performed at constant confining pressures between 1 and 30 MPa. On three specimens, the highest confining pressure measurements were performed first to inhibit thermally induced damage which might occur at lower confining pressures. At each confining pressure two complete thermal cycles were performed. The specimens were heated (to a nominal temperature of 250 C) and cooled at the nominal rate of 0.319 C per minute. The change in specimen length as a function of temperature was measured with two linear variable displacement transducers mounted on endcaps secured to the specimen. The strain increases with increasing temperature and the strain vs temperature curves are concave upward. On cooling, there is hysteresis at the higher temperatures at all confining pressures. The first heating/cooling cycle is anomalous; hysteresis is pronounced, and a permanent shortening of the specimen is observed at the termination of the cycle. The magnitude of the effect was similar for all five specimens regardless of whether the first cycle was carried out at the highest or lowest confining pressure. For subsequent cycles at all confining pressures, no permanent strain develops, and the strain versus temperature curves re very similar. The mean coefficients of thermal expansion ({alpha}) range from 7.9 to 10.8{sup {minus}6} C{sup {minus}1} at temperatures below 100 C, to 14.2 to 20.6 x 10{sup {minus}6} C{sup {minus}1} at temperatures approaching 250 C. The effect of confining pressure on thermal expansion is small. For temperatures above 175 C, the mean coefficients of thermal expansion decreases by 10--12% as the pressure increases from 1 to 30 MPa.

Shipboard fires both in the same ship hold and in an adjacent hold aboard a break-bulk cargo ship are simulated with a commercial finite-volume computational fluid mechanics code. The fire models and modeling techniques are described and discussed. Temperatures and heat fluxes to a simulated materials package are calculated and compared to experimental values. The overall accuracy of the calculations is assessed.

This report documents a preliminary evaluation of the ability of the greater confinement disposal boreholes at the Nevada Test Site to provide long-term isolation of radionuclides from the disposal of vitrified byproduct material. The byproduct material is essentially concentrated residue from processing uranium ore that contains a complex mixture of radionuclides, many of which are long-lived and present in concentrations greater than 100,000 picoCuries per gram. This material has been stored in three silos at the fernald Environmental Management Project since the early 1950s and will be vitrified into 6,000 yd{sup 3} (4,580 m{sup 3}) of glass gems prior to disposal. This report documents Sandia National Laboratories` preliminary evaluation for disposal of the byproduct material and includes: the selection of quantitative performance objectives; a conceptual model of the disposal system and the waste; results of the modeling; identified issues, and activities necessary to complete a full performance assessment.

The Alternative Landfill Cover Demonstration is a large scale field test that compares the performance of various landfill cover designs in dry environments. An important component of the comparison is the change in the moisture content of the soils throughout the different cover test plots. Time Domain Reflectometry (TDR) is the primary method for the measurement of the volumetric moisture content. Each of the covers is composed of layers of varying types and densities of soils. The probes are therefore calibrated to calculate the volumetric moisture content in each of the different soils in order to gain the optimum performance of the TDR system. The demonstration plots are constructed in two phases; a different probe is used in each phase. The probe that is used in Phase 1 is calibrated for the following soils: compacted native soil, uncompacted native soil, compacted native soil mixed with 6% sodium bentonite by weight, and sand. The probe that is used in Phase 2 is calibrated for the following soils: compacted native soil, uncompacted native soil, and sand. In addition, the probes are calibrated for the varying cable lengths of the TDR probes. The resulting empirically derived equations allow for the calculation of in-situ volumetric moisture content of all of the varying soils throughout the cover test plots in the demonstration.

The state-of-the-art in Lagrangian methods for the grid-free simulation of three-dimensional, incompressible, high Reynolds number, internal and/or external flows is surveyed. Specifically, vortex and velicity (or impulse) element methods are introduced. The relative merits of various available techniques and the outstanding challenges in simulating the processes of convection and diffusion, as well as in satisfying the wall boundary conditions are discussed individually. Issues regarding the stretch and solenoidality of vorticity are also discussed. A potentially successful algorithm for simulating the flow around a parachute is proposed as well.

A methodology for the evaluation of complex electromagnetics problems is presented. The methodology reduces the computational requirements for the analysis of large scale computational electromagnetics problems by hybridizing the method of moments and physical optics techniques. The target model is based on triangular facets and the incident field source by its system response function. Data which can be obtained from the analysis are radar cross section, power spectral density, and range profiles.

Surface-micromachined silicon inertial sensors are limited to relatively high-G applications in part because of the fundamental limitations on proof mass imposed by the manufacturing technology. At the same time, traditional micromolding technologies such as LIGA do not lend themselves to integration with electronics, a capability which is equally necessary for high-performance inertial sensors. The silicon micromolding processes described in this report promise to offer both larger proof masses and integrability with on-chip electronics. In Sandia`s silicon micromolding process, the proof mass is formed using a mold which is first recessed into the substrate using a deep silicon trench etch, then lined with a sacrificial or etch-stop layer, and filled with mechanical polysilicon. Since the mold is recessed into the substrate, the whole micromechanical structure can be formed, planarized, and integrated with standard silicon microelectronic circuits before the release etch. In addition, unlike surface-micromachined parts, the thickness of the molded parts is limited by the depth of the trench etch (typically 10--50 {micro}m) rather than the thickness of deposited polysilicon (typically 2 {micro}m). 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. The authors 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 including high-performance inertial sensing systems.

Discharge capacitors were designed based on materials with antiferroelectric (AFE) to ferroelectric (FE) field enforced transitions that had 10 times the capacitance of relaxor ferroelectric or state of the art BaTiO{sub 3} materials in the voltage range of interest. Nonlinear RLC circuit analysis was used to show that the AFE to FE materials have potentially more than 2 times the peak discharge current density capability of the BaTiO{sub 3} or lead magnesium niobate (PMN) based relaxor materials. Both lead lanthanum zirconium tin titanate (PLZST) AFE to FE field enforced phase transition materials and PMN based relaxor materials were fabricated and characterized for Sandia`s pulse discharge capacitor applications. An outstanding feature of the PLZST materials is that there are high field regimes where the dielectric constant increases substantially, by a factor of 20 or more, with applied field. Specifically, these materials have a low field dielectric constant of 1,000, but an effective dielectric constant of 23,000 in the electric field range corresponding to the FE to AFE transition during discharge. Lead magnesium niobate (PMN) based relaxor materials were also investigated in this project because of their high dielectric constants. While the PMN based ceramics had a low field dielectric constant of 25,000, at a field corresponding to half the charging voltage, approximately 13 kV/cm, the dielectric constant decreases to approximately 7,500.

The flow behavior of liquid metals at solid interfaces is critically important to successful welding, brazing, soldering and the synthesis of metal/ceramic composites. Continuum flow models frequently fail to reliably predict wetting behavior because they are based upon bulk fluid properties, rather than microscopic flow processes at the actual solid/liquid interface. Improved understanding of interfacial liquid flow is hindered by the paucity of experimental measurements at this microscopic level. This report describes a new approach, Acoustic Wave Damping (AWD), to measuring viscoelastic properties of liquid metal layers in the nanometer thickness regime. The AWD experiment measures the frequency response of a quartz crystal microbalance in contact with a viscoelastic layer. An equivalent circuit model and continuum acoustic theory relate this electrical response to mechanical energy storage and dissipative loss. For viscoelastic layers of known thickness and density, a quantitative complex shear modulus can be determined from the AWD data. Studies of self-assembled monolayers (SAMs) demonstrate sensitivity to monolayer structure and bonding. Molecular dynamics simulations relate these atomistic properties to the ensemble response. AWD measurements of ultra-thin liquid indium layers reveal metastable undercooling for 10--50 nm thick indium layers. Continued refinement of the AWD technique and the addition of complementary interface characterization techniques will enable definitive studies of ultra-thin molten metals.

The on-site inspection provisions in many current and proposed arms control agreements require extensive preparation and training on the part of both the Inspection Teams (inspectors) and Inspected Parties (host). Current training techniques include table-top inspections and practice inspections. The Augmented Computer Exercise for Inspection Training (ACE-IT), an interactive computer training tool, increases the utility of table-top inspections. ACE-IT has been designed to provide training for challenge inspections under the Chemical Weapons Convention (CWC); however, this training tool can be modified for other inspection regimes. Although ACE-IT provides training from notification of an inspection through post-inspection activities, the primary emphasis of ACE-IT is in the inspection itself--particularly with the concept of managed access. ACE-IT also demonstrates how inspection provisions impact compliance determination and the protection of sensitive information. This User`s Guide describes the use of the ACE-IT training software.

The on-site inspection provisions in many current and proposed arms control agreements require extensive preparation and training on the part of both the Inspection Teams (inspectors) and Inspected Parties (host). Current training techniques include table-top inspections and practice inspections. The Augmented Computer Exercise for Inspection Training (ACE-IT), an interactive computer training tool, increases the utility of table-top inspections. ACE-IT has been designed to provide training for challenge inspections under the Chemical Weapons Convention (CWC); however, this training tool can be modified for other inspection regimes. Although ACE-IT provides training from notification of an inspection through post-inspection activities, the primary emphasis of ACE-IT is in the inspection itself--particularly with the concept of managed access. ACE-IT also demonstrates how inspection provisions impact compliance determination and the protection of sensitive information. This Technical Manual describes many of the technical aspects of the ACE-IT training software.

The on-site inspection provisions in many current and proposed arms control agreements require extensive preparation and training on the part of both the Inspected Party and the Inspection Team. Current training techniques include table-top inspections and practice inspections. The Augmented Computer Exercise for Inspection Training (ACE-IT), an interactive computer training tool, increases the utility of table-top inspections. ACE-IT has been designed to provide training for a hypothetical challenge inspection under the Chemical Weapons Convention (CWC); however, this training tool can be modified for other inspection regimes. Although ACE-IT provides training from notification of an inspection through post-inspection activities, the primary emphasis of ACE-IT is in the inspection itself--particularly with the concept of managed access. ACE-IT also demonstrates how inspection provisions impact compliance determination and the protection of sensitive information. The Exercise Manual supplements the ACE-IT software by providing general information on on-site inspections and detailed information for the CWC challenge inspection exercise. The detailed information includes the pre-inspection briefing, maps, list of sensitive items, medical records, and shipping records.