Sandia National Laboratories, New Mexico, conducts the Energy Storage Systems Program, which is sponsored by the US Department of Energy`s Office of Utility Technologies. The goal of this program is to collaborate with industry in developing cost-effective electric energy storage systems for many high-value stationary applications. Sandia National Laboratories is responsible for the engineering analyses, contracted development, and testing of energy storage components and systems. This report details the technical achievements realized during fiscal year 1997. 46 figs., 20 tabs.
This is the third report in a series of studies to examine how US attitudes about nuclear security are evolving in the post-Cold War era and to identify trends in public perceptions and preferences relevant to the evolution of US nuclear security policy. It presents findings from three surveys: a nationwide telephone survey of randomly selected members of the US general public; a written survey of randomly selected members of American Men and Women of Science; and a written survey of randomly selected state legislators from all fifty US states. Key areas of investigation included nuclear security, cooperation between US and Russian scientists about nuclear issues, vulnerabilities of critical US infrastructures and responsibilities for their protection, and broad areas of US national science policy. While international and US national security were seen to be slowly improving, the primary nuclear threat to the US was perceived to have shifted from Russia to China. Support was found for nuclear arms control measures, including mutual reductions in stockpiles. However, respondents were pessimistic about eliminating nuclear armaments, and nuclear deterrence continued to be highly values. Participants favored decreasing funding f/or developing and testing new nuclear weapons, but supported increased investments in nuclear weapons infrastructure. Strong concerns were expressed about nuclear proliferation and the potential for nuclear terrorism. Support was evident for US scientific cooperation with Russia to strengthen security of Russian nuclear assets. Elite and general public perceptions of external and domestic nuclear weapons risks and external and domestic nuclear weapons benefits were statistically significantly related to nuclear weapons policy options and investment preferences. Demographic variables and individual belief systems were systematically related both to risk and benefit perceptions and to policy and spending preferences.
Classified designs usually include lesser classified (including unclassified) components. An engineer working on such a design needs access to the various sub-designs at lower classification levels. For simplicity, the problem is presented with only two levels: high and low. If the low-classification component designs are stored in the high network, they become inaccessible to persons working on a low network. In order to keep the networks separate, the component designs may be duplicated in all networks, resulting in a synchronization problem. Alternatively, they may be stored in the low network and brought into the high network when needed. The latter solution results in the use of sneaker-net (copying the files from the low system to a tape and carrying the tape to a high system) or a file transfer guard. This paper shows how an FTP Guard was constructed and implemented without degrading the security of the underlying B3 platform. The paper then shows how the guard can be extended to an FTP proxy server or an HTTP proxy server. The extension is accomplished by allowing the high-side user to select among items that already exist on the low-side. No high-side data can be directly compromised by the extension, but a mechanism must be developed to handle the low-bandwidth covert channel that would be introduced by the application.
In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards white building much smaller lot sizes remains. To meet this challenge, specific areas need more attention, including fast and on-target process start-up, low volume statistical process control, process characterization with small experiments, and estimating reliability given few actual performance tests of the product. In this paper the authors address the issue of low volume statistical process control. They investigate an adaptive filtering approach to process monitoring with a relatively short time series of autocorrelated data. The emphasis is on estimation and minimization of mean squared error rather than the traditional hypothesis testing and run length analyses associated with process control charting. The authors develop an adaptive filtering technique that assumes initial process parameters are unknown, and updates the parameters as more data become available. Using simulation techniques, they study the data requirements (the length of a time series of autocorrelated data) necessary to adequately estimate process parameters. They show that far fewer data values are needed than is typically recommended for process control applications. And they demonstrate the techniques with a case study from the nuclear weapons manufacturing complex.
Risk assessment methodologies are ready to enter their third generation. In this next generation, assessment will be based on a whole system understanding of the system to be assessed. To realize this vision of risk management, the authors have begun development of an extensible software tool kit. This tool kit breaks with the traditional approach to assessment by having the analyst spend the majority of the assessment time building an explicit model that documents in a single framework the various facets of the system, such as the system`s behavior, structure, and history. Given this explicit model of the system, a computer is able to automatically produce a standard assessment products, such as fault trees and event trees. This brings with it a number of advantages relative to current risk management tools. Among these are a greater sense of completeness and correctness in assessment results and the ability to preserve and later employ lessons learned.
The sol-gel chemistry of a variety of trialkoxysilanes with different organic substituents, with methoxide or ethoxide substituents on silicon was examined at varying monomer concentrations ranging up to neat monomer and with different catalysts. Gels were prepared from tetramethoxysilane and tetraethoxysilane at identical concentrations for purposes of comparison. The polymerization reactions were monitored for the formation of gels, insoluble precipitates, soluble polymers, or polyhedral oligosilsesquioxanes.
A comprehensive critical infrastructure analysis of the People`s Republic of China was performed to address questions about China`s ability to meet its long-term grain requirements and energy needs and to estimate greenhouse gas emissions in China likely to result from increased agricultural production and energy use. Four dynamic computer simulation models of China`s infrastructures--water, agriculture, energy and greenhouse gas--were developed to simulate, respectively, the hydrologic budgetary processes, grain production and consumption, energy demand, and greenhouse gas emissions in China through 2025. The four models were integrated into a state-of-the-art comprehensive critical infrastructure model for all of China. This integrated model simulates diverse flows of commodities, such as water and greenhouse gas, between the separate models to capture the overall dynamics of the integrated system. The model was used to generate projections of China`s available water resources and expected water use for 10 river drainage regions representing 100% of China`s mean annual runoff and comprising 37 major river basins. These projections were used to develop estimates of the water surpluses and/or deficits in the three end-use sectors--urban, industrial, and agricultural--through the year 2025. Projections of the all-China demand for the three major grains (corn, wheat, and rice), meat, and other (other grains and fruits and vegetables) were also generated. Each geographic region`s share of the all-China grain demand (allocated on the basis of each region`s share of historic grain production) was calculated in order to assess the land and water resources in each region required to meet that demand. Growth in energy use in six historically significant sectors and growth in greenhouse gas loading were projected for all of China.
This paper explores the use of discrete-event simulation for the design and control of physical protection systems for fixed-site facilities housing items of significant value. It begins by discussing several modeling and simulation activities currently performed in designing and analyzing these protection systems and then discusses capabilities that design/analysis tools should have. The remainder of the article then discusses in detail how some of these new capabilities have been implemented in software to achieve a prototype design and analysis tool. The simulation software technology provides a communications mechanism between a running simulation and one or more external programs. In the prototype security analysis tool, these capabilities are used to facilitate human-in-the-loop interaction and to support a real-time connection to a virtual reality (VR) model of the facility being analyzed. This simulation tool can be used for both training (in real-time mode) and facility analysis and design (in fast mode).
Mixed arsenide/antimonide materials have unique properties which make them potentially valuable for use in VCSELs operating at wavelengths longer than 1 {micro}m. The authors present their progress in applying these materials to VCSEL designs for 1--1.55 {micro}m.
This report describes the results of an analysis to determine the economic and operational value of battery storage to wind and photovoltaic (PV) generation technologies to the Sacramento Municipal Utility District (SMUD) system. The analysis approach consisted of performing a benefit-cost economic assessment using established SMUD financial parameters, system expansion plans, and current system operating procedures. This report presents the results of the analysis. Section 2 describes expected wind and PV plant performance. Section 3 describes expected benefits to SMUD associated with employing battery storage. Section 4 presents preliminary benefit-cost results for battery storage added at the Solano wind plant and the Hedge PV plant. Section 5 presents conclusions and recommendations resulting from this analysis. The results of this analysis should be reviewed subject to the following caveat. The assumptions and data used in developing these results were based on reports available from and interaction with appropriate SMUD operating, planning, and design personnel in 1994 and early 1995 and are compatible with financial assumptions and system expansion plans as of that time. Assumptions and SMUD expansion plans have changed since then. In particular, SMUD did not install the additional 45 MW of wind that was planned for 1996. Current SMUD expansion plans and assumptions should be obtained from appropriate SMUD personnel.
Single event gate rupture (SEGR) is a catastrophic failure mode that occurs in dielectric materials that are struck by energetic heavy ions while biased under a high electric field condition. SEGR can reduce the critical electric field to breakdown to less than half the value observed in normal voltage ramp reliability tests. As electric fields in gate oxides increase to greater than 5 MV/cm in advanced MOS technologies, the impact of SEGR on the reliability of space based electronics must be assessed. In this summary, the authors explore the nature of SEGR in oxides with thickness from 7 nm to less than 5 nm, where soft breakdown is often observed during traditional reliability tests. They discuss the possible connection between the present understanding of SEGR and voltage stress breakdown models.
The Waste Isolation Pilot Plant (WIPP) is under development by the US Department of Energy (DOE) for the geologic disposal of transuranic waste. The primary regulatory requirements (i.e., 40 CFR 191 and 40 CFR 194) placed on the WIPP by the US Environmental Protection Agency (EPA) involve a complementary cumulative distribution function (CCDF) for normalized radionuclide releases to the accessible environment. The interpretation and use of this CCDF from a decision analysis perspective is discussed and illustrated with results from the 1996 performance assessment for the WIPP, which was carried out to support a compliance certification application by the DOE to the EPA for the WIPP.
Non-shrinking polymers are desirable as encapsulants for strain-free packaging for electronics. Ring-opening polymerizations of cyclic monomers such as lactams, cyclic ethers, and cyclic oligosiloxanes have proven an effective strategy for reducing shrinkage. In this report the authors examined the loss of volume during the ring-opening polymerization of neat 2,2,5,5-tetramethyl-l-oxa-2,5-disilacyclopentane to give poly(1,2-ethylene-bis(dimethyl-siloxane)). Monomer 1 is under sufficient strain (8--12 kcal/mole) to permit its facile base-catalyzed polymerization to afford high molecular polymer. Monomer 1 was prepared by hydrolyzing and condensing either 1,2-bis(chlorodimethylsilyl)ethane or 1,m2-bis(dimethylethoxysilyl)ethane to give a low molecular weight oligomer. Pyrolysis of this oligomer with potassium hydroxide at 280 C afforded the cyclic monomer in good yield (60--70%). The ease with which the oligomer can be converted to monomer also led the authors to investigate the potential for recycling the high molecular weight polymer.
A backfill system has been designed for the Waste Isolation Pilot Plant (WIPP) which will control the chemical environment of the post-closure repository to a domain where the actinide solubility is within its lowest region. The actinide solubility is highly dependent on the chemical species which constitute the fluid, the resulting pH of the fluid, and the oxidation state of the actinide which is stable under the specific conditions. The use of magnesium oxide (MgO) has the backfill material not only controls the pH of the expected fluids, but also effectively removes carbonate from the system, which has a significant impact on actinide solubility. The backfill selection process, emplacement system design, and confirmatory experimental results are presented.
In this paper the authors discuss the leveling process by which a business process ontology is formed in a distributed, multi-lingual, multi-stakeholder environment, with attention to realizing elicitation mechanisms that maintain registration of users` terms with the common ontology. Business processes are recognized from use-case analysis, specified in terms of the common ontology, and realized as operations on the components of a transaction: a temporally extended, complex, distributed object. A primary advantage of this approach is that users see private terminologies while the transaction object is specified in terms of the common ontology, and registration between the two is automatic and continuous. Ready realization of multiple interfaces to stakeholders, independently constructed validation and verification mechanisms, distributed data, and a standard elicitation mechanism and process are other advantages. The language formation process was used successfully during the development of the Border Trade Facilitation System, an agent-oriented mechanism that conducts international border-crossing transactions. In this implementation, agents operating within a federated architecture construct, populate, verify, certify, and manipulate a distributed composite transaction object to effect transport of goods over the US/Mexico border.
In order to promote internatinal confidence that the US and Russia are disarming per their commitments under Article 6 of the Non-Proliferation Treaty, an international verification regime may be applied to US and Russian excess fissile materials. Initially, it is envisioned that this verification regime would be applied at storage facilities; however, it should be anticipated that the verificatino regime would continue throughout any material disposition activities, should such activities be pursued. once the materials are accepted into the verification regime, it is assumed that long term monitoring will be used to maintain continuity of knowledge. The requirements for long term storage monitoring include unattended operation for extended periods of time, minimal intrusiveness on the host nation`s safety and security activities, data collection incorporating data authentication, and monitoring redundancy to allow resolution of anomalies and to continue coverage in the event of equipment failures. Additional requirements include effective data review and analysis processes, operation during storage facility loading, procedure for removal of inventory items for safety-related surveillance, and low cost, reliable equipment. A monitoring system might include both continuous monitoring of storagecontainers and continuous area monitoring. These would be complemented with periodic on-site inspections. A fissile material storage facility is not a static operation. The initial studies have shown there are a number of volid reasions why a host nation may need them to remove material from the storage facility. A practical monitoring system must be able to accommodate necessary material movements.
Deep-reactive ion etching (DRIE) of silicon, also known as high-aspect-ratio silicon etching (HARSE), is distinguished by fast etch rates ({approximately}3 {micro}m/min), crystal orientation independence, anisotropy, vertical sidewall profiles and CMOS compatibility. By using through-wafer HARSE and stopping on a dielectric film placed on the opposite side of the wafer, freestanding dielectric membranes were produced. Dielectric membrane-based sensors and actuators fabricated in this way include microhotplates, flow sensors, valves and magnetically-actuated flexural plate wave (FPW) devices. Unfortunately, low-stress silicon nitride, a common membrane material, has an appreciable DRI etch rate. To overcome this problem HARSE can be followed by a brief wet chemical etch. This approach has been demonstrated using KOH or HF/Nitric/Acetic etchants, both of which have significantly smaller etch rates on silicon nitride than does DRIE. Composite membranes consisting of silicon dioxide and silicon nitride layers are also under evaluation due to the higher DRIE selectivity to silicon dioxide.
For more than two decades, risk analysts have relied on powerful logic-based models to perform their analyses. However, the applicability of these models has been limited because they can be complex and expensive to develop. Analysts must frequently start from scratch when analyzing a new (but similar) system because the understanding of how the system works exists only in the mind of the analyst and is only incompletely instantiated in the actual logic model. This paper introduces the notion of using explicit object-oriented system models, such as those embodied in computer-aided software engineering (CASE) tools, to document the analyst`s understanding of the system and appropriately capture how the system works. It also shows that from these models, standard assessment products, such as fault trees and event trees, can be automatically derived.
The authors describe the design, modeling, fabrication and initial testing of a new test structure for friction measurement in MEMS. The device consists of a cantilevered forked beam and a friction pad attached via a hinge. Compared to previous test structures, the proposed structure can measure friction over much larger pressure ranges, yet occupies one hundred times less area. The placement of the hinge is crucial to obtaining a well-known and constant pressure distribution in the device. Static deflections on the device were measured and modeled numerically, Preliminary results indicate that friction pad slip is sensitive to friction pad normal force.
In this paper a hybrid, finite element/boundary element method which can be used to solve for particle diffusion in semi-infinite domains containing geometric obstructions and a variable advective field is presented. In previous work either boundary element or finite element/difference methods were used to solve for particle concentrations in an advective domain. These methods of solution had a number of limitations. Due to limitations in computing spatially dependent Green`s functions, the boundary element method of solution was limited to domains containing only constant advective fields, and due to its inherent formulation, finite element/difference methods were limited to only domains of finite spatial extent. Thus, where the finite element solution was limited, the boundary element solution was not, and where the boundary element solution was limited, the finite element solution was not. In this paper it is proposed to split the total domain into two sub-domains where each method of solution is applicable. For each of these sub-domains, the appropriate solution method is used; thereby, producing a general method of solution for the total semi-infinite domain.
Recent developments in pulsed power technology demonstrate use of intense radiation sources (Z pinches) for driving planar shock waves in samples with spatial dimensions larger than possible with other radiation sources. Initial indications are that the use of Z pinch sources can be used to produce planar shock waves in samples with diameters of a few millimeters and thicknesses approaching one half millimeter. These dimensions allow increased accuracy of both shock velocity and particle velocity measurements. The Z pinch radiation source uses imploding metal plasma induced by self-magnetic fields applied to wire arrays to produce high temperature x-ray environments in vacuum hohlraum enclosures. Previous experiments have demonstrated that planar shock waves can be produced with this approach. A photograph of a wire array located inside the vacuum hohlraum is shown here. Typically, a few hundred individual wires are used to produce the Z pinch source. For the shock wave experiments being designed, arrays of 120 to 240 tungsten wires with a diameter of 40 mm and with individual diameters of about 10 {micro}m are used. Preliminary experiments have been performed on the Z pulsed radiation source to demonstrate the ability to obtain VISAR measurements in the Z accelerator environment. Analysis of these results indicate that another effect, not initially anticipated, is an apparent change in refractive index that occurs in the various optical components used in the system. This effect results in an apparent shift in the frequency of reflected laser light, and causes an error in the measured particle velocity. Experiments are in progress to understand and minimize this effect.
Chemical sensor arrays are an alternative to the tedious development of highly specific single-analyte detectors. Recent efforts have focused on the chemical and physical diversity of interface materials for SAW sensor arrays. However, the issues of wide dynamic range and high sensitivity must also be addressed for sensor arrays to compete in applications requiring low detection limits. Because SAW devices respond in proportion to change in mass per nominal unit area of the device surface, sensitivity is enhanced by surface modification with high-area, thin-film coating materials: a greater mass of analyte is adsorbed at a given ambient concentration. The authors are exploring several classes of electrochemically prepared high-area films, materials whose formulations and processing are well documented for applications other than chemical sensors. They present results from films formed by anodization, chemical conversion, and electroplating, yielding surface area enhancements as high as 170x.
The development and application of energy technologies for all aspects from generation to storage have improved dramatically with the advent of advanced computational tools, particularly modeling and simulation. Modeling and simulation are not new to energy technology development, and have been used extensively ever since the first commercial computers were available. However, recent advances in computing power and access have broadened the extent and use, and, through increased fidelity (i.e., accuracy) of the models due to greatly enhanced computing power, the increased reliance on modeling and simulation has shifted the balance point between modeling and experimentation. The complex nature of energy technologies has motivated researchers to use these tools to understand better performance, reliability and cost issues related to energy. The tools originated in sciences such as the strength of materials (nuclear reactor containment vessels); physics, heat transfer and fluid flow (oil production); chemistry, physics, and electronics (photovoltaics); and geosciences and fluid flow (oil exploration and reservoir storage). Other tools include mathematics, such as statistics, for assessing project risks. This paper describes a few advancements made possible by these tools and explores the benefits and costs of their use, particularly as they relate to the acceleration of energy technology development. The computational complexity ranges from basic spreadsheets to complex numerical simulations using hardware ranging from personal computers (PCs) to Cray computers. In all cases, the benefits of using modeling and simulation relate to lower risks, accelerated technology development, or lower cost projects.
The author presents a novel method for calculating the penetration of soft targets by hard projectiles by using a combination of ALE and contact surface techniques. This method allows the bifurcation in the softer material (at the point of the projectile) to be represented without sacrificing the Lagrangian representation of either the harder material or the contact interface. A series of calculations using this method show good agreement with the experimental data of Forrestal et al. This method may prove useful for a range of semi-fluid/structure interactions with friction, including simulations of manufacturing processes.
The Integrated Safety Management System (ISMS) was established to define a framework for the essential functions of managing work safely. There are five Safety Management Functions in the model of the ISMS process: (1) work planning, (2) hazards analysis, (3) hazards control, (4) work performance, and (5) feedback and improve. Recent activities at the Radioactive and Mixed Waste Management Facility underscored the importance and effectiveness of integrating the ISMS process to safely manage high-hazard work with a minimum of personnel in a timely and efficient manner. This report describes how project personnel followed the framework of the ISMS process to successfully repackage tritium-contaminated oils. The main objective was to open the boxes without allowing the gaseous tritium oxide, which had built up inside the boxes, to release into the sorting room. The boxes would be vented out the building stack until tritium concentration levels were acceptable. The carboys would be repackaged into 30-gallon drums and caulked shut. Sealing the drums would decrease the tritium off-gassing into the RMWMF.
Sandia has used flyback transformers for many years, primarily to charge capacitors for capacitive discharge units. Important characteristics of the transformer design are to meet inductance, turns ratio, and high voltage breakdown requirements as well as not magnetically saturating during each energy transfer cycle. Sandia has taken over production responsibility for magnetic components from a previous GE/LM, General Electric/Lockheed Martin, facility in Florida that produced {approximately} 50 K units per year. Vanguard Electronics is working with Sandia to transfer many of these designs to Vanguard`s small manufacturing facility in Gardena, CA. The challenge is to achieve the required high reliability and meet all the other electrical requirements with such small quantities of parts, {approximately} 100 per year. DOE requirements include high reliability {le} 3 failures per 10,000 components per 20 years while meeting numerous other environmental requirements. The basic design and prove-in required four lots of preproduction parts, extensive environmental testing, and numerous design changes. The manufacturing problems that affected performance of the transformer will be presented. These include encapsulation voids and core alignment. Also, some extended life test data that predicts long term reliability of newly produced transformers versus older designs will be compared.
This paper presents a Generalized Logistic (gLG) distribution as a unified model for Log-domain synthetic aperture Radar (SAR) data. This model stems from a special case of the G-distribution known as the G{sup 0}-distribution. The G-distribution arises from a multiplicative SAR model and has the classical K-distribution as another special case. The G{sup 0}-distribution, however, can model extremely heterogeneous clutter regions that the k-distribution cannot model. This flexibility is preserved in the unified gLG model, which is capable of modeling non-polarimetric SAR returns from clutter as well as man-made objects. Histograms of these two types of SAR returns have opposite skewness. The flexibility of the gLG model lies in its shape and shift parameters. The shape parameter describes the differing skewness between target and clutter data while the shift parameter compensates for movements in the mean as the shape parameter changes. A Maximum Likelihood (ML) estimate of the shape parameter gives an optimal measure of the skewness of the SAR data. This measure provides a basis for an optimal target detection algorithm.
In August 1995, the Nuclear Regulatory Commission (NRC) issued a policy statement proposing improved regulatory decisionmaking by increasing the use of PRA [probabilistic risk assessment] in all regulatory matters to the extent supported by the state-of-the-art in PRA methods and data. A key aspect in using PRA in risk-informed regulatory activities is establishing the appropriate scope and attributes of the PRA. In this regard, ASME decided to develop a consensus PRA Standard. The objective is to develop a PRA Standard such that the technical quality of nuclear plant PRAs will be sufficient to support risk-informed regulatory applications. This paper presents examples recommendations for the systems analysis element of a PRA for incorporation into the ASME PRA Standard.
Deep reactive ion etching (DRIE) of silicon was utilized to fabricate dielectric membrane-based devices such as microhotplates, valves and flexural plate wave (FPW) devices. Through-wafer DRIE is characterized by fast etch rates ({approximately} 3 {micro}m/min), crystal orientation independence, vertical sidewall profiles and CMOS compatibility. Low-stress silicon nitride, a popular membrane material, has an appreciable DRIE etch rate. To overcome this limitations DRIE can be accompanied by a brief wet chemical etch. This approach has been demonstrated using KOH or HF/Nitric/Acetic etchants, both of which have significantly lower etch rates on silicon nitride than does DRIE. The DRIE etch properties of composite membranes consisting of silicon dioxide and silicon nitride layers are also under evaluation due to the higher DRIE selectivity to silicon dioxide.
Molecular recognition is an important topic when searching for new, selective coating materials for chemical sensing. Recently, the general idea of molecular recognition in the gas phase was challenged by Grate et al. However, in earlier thickness-shear mode resonator (TSMR) investigations, convincing evidence was presented for specific recognition of particular analyte target molecules. In this study, the authors systematically investigated coatings previously shown to be highly selective, such as the bucket-like cyclodextrins for chiral recognition, Ni-camphorates for the specific detection of the bases pyridine and DMMP (dimethylmethylphosphonate), and phthalocyanines to specifically detect benzene, toluene, and xylene (BTX).
chemical sensor arrays eliminate the need to develop a high-selectivity material for every analyte. The application of pattern recognition to the simultaneous responses of different microsensors enables the identification and quantification of multiple analytes with a small array. Maximum materials diversity is the surest means to create an effective array for many analytes, but using a single material family simplifies coating development. Here the authors report the successful combination of an array of six dendrimer films with mass-sensitive SAW (surface acoustic wave) sensors to correctly identify 18 organic analytes over wide concentration ranges, with 99.5% accuracy. The set of materials for the array is selected and the results evaluated using Sandia`s Visual-Empirical Region of Influence (VERI) pattern recognition (PR) technique. The authors evaluated eight dendrimer films and one self-assembled monolayer (SAM) as potential SAW array coatings. The 18 organic analytes they examined were: cyclohexane, n-hexane, i-octane, kerosene, benzene, toluene, chlorobenzene, carbon tetrachloride, trichloroethylene, methanol, n-propanol, pinacolyl alcohol, acetone, methyl isobutyl ketone, dimethylmethylphosphate, diisopropylmethylphosphonate, tributylphosphate, and water.
Chemical-Mechanical-Polishing (CMP), first used as a planarization technology in the manufacture of multi-level metal interconnects for high-density Integrated Circuits (IC), is readily adapted as an enabling technology in MicroElectroMechanical Systems (MEMS) fabrication, particularly polysilicon surface micromachining. The authors have demonstrated that CMP enhances the design and manufacturability of MEMS devices by eliminating several photolithographic definition and film etch issues generated by severe topography. In addition, CMP planarization readily allows multi-level polysilicon structures comprised of 4- or more levels of polysilicon, eliminates design compromise generated by non-planar topography, and provides an avenue for integrating different process technologies. A recent investigation has also shown that CMP is a valuable tool for assuring acceptable optical flatness of micro-optical components such as micromirrors. Examples of these enhancements include: an extension of polysilicon surface-micromachining fabrication to a 5-level technology, a method of monolithic integration of electronics and MEMS, and optically flat micromirrors.
The declining state of the Russian military and precarious Russian economic condition will give the US considerable advantages at the START III bargaining table. Taking the US-RF asymmetries into account, this paper discusses a menu of START III measures the US could ask for, and measures it could offer in return, in attempting to negotiate an equitable treaty. Measures the US might seek in a START III treaty include: further reductions in deployed strategic nuclear warheads, irreversibility of reductions through warhead dismantlement; beginning to bring theater nuclear weapons under mutual control, and increased transparency into the Russian nuclear weapons complex. The US may, however, wish to apply its bargaining advantages to attempting to achieve the first steps toward two long-range goals that would enhance US security: bringing theater nuclear weapons into the US-RF arms control arena, and increasing transparency into the Russian nuclear weapons complex. In exchange for measures relating to these objectives, the US might consider offering to Russia: Further strategic weapons reductions approaching levels at which the Russians believe they could maintain a degree of parity with the US; Measures to decrease the large disparities in potential deliver-system uploading capabilities that appear likely under current START II/START III scenarios; and Financial assistance in achieving START II/START III reductions as rapidly as is technically possible.
This paper presents an overview of the issues associated with applying a domain-decomposition message-passing paradigm to the parallel implementation of both explicit and semi-implicit projection algorithms. The use of an element-based domain decomposition with an efficient solution strategy for the pressure field is shown to yield a scalable, parallel solution method capable of treating complex flow problems where high-resolution grids are required. In addition, the use of an SSOR or Jacobi preconditioned conjugate gradient solver with an A-conjugate projection reduces the computational time for the solution of the pressure field, and yields parallel efficiencies above 80% for computations with O(250) elements per processor. The parallel projection solver is verified using a series of 2-D and 3-D benchmarks designed to evaluate time-accurate flow solution methods. Finally, the extension of the projection algorithm to reacting flows is demonstrated for a time-dependent vortex-shedding problem.
The ability to make in-situ performance measurements of MEMS operating at high speeds has been demonstrated using a new image analysis system. Significant improvements in performance and reliability have directly resulted from the use of this system.
Despite evidence of significant management contributions to the causes of major accidents, recent events at Millstone Nuclear Power Station in the US and Ontario Hydro in Canada might lead one to conclude that the significance of safety culture, and the role of management in developing and maintaining an appropriate safety culture, is either not being understood or not being taken serious as integral to the safe operation of some complex, high-reliability operations. It is the purpose of this paper to address four aspects of management that are particularly important to safety culture, and to illustrate how development of an appropriate safety culture is more a matter of common sense than rocket science.
Emergent technologies often suffer from a lack of an installed manufacturing base and an obvious dominant manufacturing technique. Firms which base their search for competitive advantage on emergent disruptive technologies must make hard production choices and endure major manufacturing discontinuities. The authors as well as many other firms, are now facing these challenges with the embrace of microsystems technologies. They add to the literature by providing a set of criteria for firms investing in emergent disruptive technologies. Sandia has long been associated as a pioneer in the development of new manufacturing techniques. Microsystems is just the current in a long line of manufacturing technologies that have been considered for mission critical system applications. The authors as well as others, have had to make the hard choice of investing in specific microsystems manufacturing techniques. Important considerations in the technique choice include: the existing internal manufacturing bases, commonality with existing commercial manufacturing infrastructure, current and projected critical performance characteristics, learning curves, the promise to add new but un-thought-of functionally to existing systems, and the anticipated ability to qualify devices built from the technique for mission critical applications.
For many modern day portable electronic applications, low power high speed devices have become very desirable. Very high values of f{sub T} and f{sub MAX} have been reported with InGaAs/InP heterojunction bipolar transistors (HBTs), but only under high bias and high current level operating conditions. An InGaAs/InP ultra-lowpower HBT with f{sub MAX} greater than 10 GHz operating at less than 20 {micro}A has been reported for the first time in this work. The results are obtained on a 2.5 x 5 {micro}m{sup 2} device, corresponding to less than 150 A/cm{sup 2} of current density. These are the lowest current levels at which f{sub MAX} {ge} 10 GHz has been reported.
In the past, most defense microelectronics components were packaged in ceramic, hermetic enclosures. PEMs are not hermetic because the plastic molding compounds are permeable to moisture. This lack of hermeticity creates an unknown liability, especially with respect to corrosion of the metallization features. This potential liability must be addressed to ensure long-term reliability of these systems is maintained under conditions of long-term dormant storage. However, the corrosion process is difficult to monitor because it occurs under the encapsulating plastic and is therefore not visible. The authors have developed techniques that allow them to study corrosion of Al bondpads and traces under relevant atmospheric corrosion conditions. The cornerstone of this capability is the ATC 2.6, a microelectronic test device designed at Sandia National Laboratories. Corrosion tests were performed by exposing test chips to aggressive environments. The electrical response of the ATC indicated an increase in bondpad resistance with exposure time. Note that the change in resistance is not uniform from one bondpad to another. This illustrates the stochastic nature of the corrosion process. The change in resistance correlated with visual observation of corrosion of the bondpads on the unencapsulated test chips.
Multispectral image analysis of magnetic resonance imaging (MRI) data has been performed using an empirically-derived clustering algorithm. This algorithm groups image pixels into distinct classes which exhibit similar response in the T{sub 2} 1st and 2nd-echo, and T{sub 1} (with ad without gadolinium) MRI images. The grouping is performed in an n-dimensional mathematical space; the n-dimensional volumes bounding each class define each specific tissue type. The classification results are rendered again in real-space by colored-coding each grouped class of pixels (associated with differing tissue types). This classification method is especially well suited for class volumes with complex boundary shapes, and is also expected to robustly detect abnormal tissue classes. The classification process is demonstrated using a three dimensional data set of MRI scans of a human brain tumor.
Researchers at the National Wind Technology Center have identified a need to acquire data on the rotor of an operating wind turbine at precisely the same time as other data is acquired on the ground or on a non-rotating part of the wind turbine. The researchers will analyze that combined data with statistical and correlation techniques to clearly establish phase information and loading paths and insights into the structural loading of wind turbines. A data acquisition unit has been developed to acquire the data from the rotating system at precise universal times specified by the user. The unit utilizes commercial data acquisition hardware, spread-spectrum radio modems, and a Global Positioning Satellite receiver as well as a custom-built programmable logic device. A prototype of the system is now operational, and initial field deployment is anticipated this summer.
A specialized hyperspectral imager has been developed that preprocesses the spectra from an image before the light reaches the detectors. This "optical computer" does not allow the flexibility of digital post-processing. However, the processing is done in real time and the system can examine = 2 x 10{sup 6} scene pixels/sec. Therefore, outdoors it could search for pollutants, vegetation types, minerals, or man-made objects. On a high- speed production line it could identify defects in sheet products like plastic wrap or film, or on painted or plastic parts. ISIS is a line scan imager. A spectrally dispersed slit image is projected on a Spatial Light Modulator. The SLM is programmed to take the inner product of the spectral intensity vector and a spectral basis vector. The SLM directs the positive and negative parts of the inner product to different linear detector arrays so the signal difference equals the inner product. We envision a system with one telescope and =4 SLMS.
Engineered Surety Using the Risk Equation (EnSURE) is a new approach being developed by Sandia National Laboratories for determining and mitigating risk. The EnSURE approach is based on the risk equation, which can be defined by the following equation: R = (Pa)(1-Pe)(C). Where R is risk, Pa is the likelihood of attack, Pe is the system effectiveness and C is the consequence. EnSURE considers each of the components of risk to help in assessing surety (e.g. security, safety, environmental) and providing for the most cost-effective ways to reduce risk. EnSURE is intended to help in evaluating and reducing the risk from either man-caused or natural events. It will help the decision-makers identify possible targets, evaluate the consequences of an event, assess the risk based on the threat and the existing conditions and then help in the application of mitigating measures. EnSURE is in the development stages. It builds on existing and ongoing development activities at Sandia, as well as the considerable work done in the fields of consequence analysis, risk analysis and intelligence. The components of EnSURE include consequences, constraints, threat, target/goal identification, facility/process characterization, evaluation and analysis, system improvement, and decision making. This paper provides a brief description of EnSURE.
This contribution describes three interoperability scenarios for the ATM Security Message Exchange (SME) protocol. These scenarios include network-wide signaling support for the Security Services Information Element, partial signaling support wherethe SSIE is only supported in private or workgroup ATM networks, and the case where the SSIE is nonsupported by any network elements (exceptthosethat implement security services). Explanatory text is proposed for inclusion infection 2.3 of the ATM Security Specification, Version 1.0.
Department of Energy and Defense Programs systems are becoming increasingly reliant on the use of optical technologies that must perform under a range of ionizing radiation environments. In particular, the radiation response of materials under consideration for applications in direct optical initiation (D.O.I.) schemes must be well characterized. In this report, transient radiation effects observed in a KD*P crystal are characterized. Under gamma exposure with 2 MeV photons in a 20--30 nsec pulse, the authors observe induced absorption at 1.06 {micro}m that causes a peak decrease in overall sample transmittance of only 10%. This induced loss is seen to recover fully within the first 30 {micro}sec.
Department of Energy and Defense Programs systems are becoming increasingly reliant on the use of optical technologies that must perform under a range of ionizing radiation environments. In particular, the radiation response of materials under consideration for applications in direct optical initiation (D.O.I.) schemes must be well characterized. In this report, transient radiation effects observed in Schott filter glass S-7010 are characterized. Under gamma exposure with 2 MeV photons in a 20--30 nsec pulse, the authors observe strong initial induced fluorescence in the red region of the spectrum followed by significant induced absorption over the same spectral region. Peak induced absorption coefficients of 0.113 cm{sup {minus}1} and 0.088 cm{sup {minus}1} were calculated at 800 nm and 660 nm respectively.
From July 29 to 31, 1997, the Surety Assessment Center at Sandia National Laboratories hosted the second international symposium on High Consequence Operations Safety, HCOSSII. The two and one-half day symposium allowed participants to share strategies, methodologies, and experiences in high consequence engineering and system design. The symposium addressed organizational influences on high consequence safety, assessment and analysis processes, lessons-learned from high consequence events, human factors in safety, and software safety. A special session at the end of the symposium featured a presentation by Federal Nuclear Center--All Russian Research Institute of Experimental Physics and Sandia National Laboratories personnel on their joint efforts to establish the International Surety Center for Energy Intensive and High Consequence Systems and Infrastructures.
Often the drilling of an oil well is followed by a logging process to characterize the region immediately surrounding the well bore. The electromagnetic (EM) induction tool, which provides the formation resistivity, is among the most frequently run logs. A preliminary study has been conducted to analyze the feasibility of three dimensional (3D) electromagnetic (EM) imaging from a single borehole. The logging tool consists of a vertical magnetic dipole source and multiple 3 component magnetic field receivers offset at different distances from the source. Synthetic data calculated with a 3D finite difference code demonstrate that the phase of the horizontal magnetic fields provides the critical information on the three dimensionality of the medium. A 3D inversion algorithm is then employed to demonstrate the plausibility of 3D inversion using 3 component magnetic field data. Finally, problems associated with introducing biased noise into the horizontal components of the field through misalignment of the logging tool is discussed.
The United States conducted over 100 atmospheric nuclear tests at the Nevada Test Site from 1951 through 1962. Some of the earliest tests caused unexpected damage, primarily broken glass and cracked plaster, in Las Vegas and other surrounding communities. To address this problem, Sandia initiated a program to monitor and predict the pressure waves around NTS. Infrasound recording systems were developed, then field for all tests beginning with Operation Buster in October 1951. Investigators soon discovered that near-surface temperature inversions and wind profiles caused the damaging pressures in Las Vegas. A typical test was recorded at about a dozen stations from the Control Point on NTS to as far away as Pasadena, CA. In addition, some tests in the South Pacific were monitored, as well as numerous chemical explosions. Strip charts recorded signals in the frequency band from 0.05 to 30 Hz, and the paper tapes were achieved at Sandia in the early 1970s. The NTS events ranged in yield from below 1 ton to 74 kilotons; source altitudes varied from near ground level (including some cratering experiments) to as high as 11 km. The resulting data contain a wealth of information on the source function, yield scaling and regional propagation of infrasound signals from atmospheric explosions. The renewed interest in infrasonic monitoring for CTBT verification has prompted the authors to exhume some of the archived records. The authors plan to digitize the signals from several tests and evaluate their applicability to CTBT issues. In addition, they will collect any existing parametric measurements for these records (arrival times, amplitudes, etc.). All data will be converted to CSS database format and made available to the research community. If appropriate, the resulting information could also be included in the Knowledge Base under development for CTBT monitoring.
The US Department of Energy is funding the development of the Multi-spectral Thermal Imager (MTI), a satellite-based multi-spectral (MS) thermal imaging sensor scheduled for launch in October 1999. MTI is a research and development (R and D) platform to test the applicability of multispectral and thermal imaging technology for detecting and monitoring signs of proliferation of weapons of mass destruction. During its three-year mission, MTI will periodically record images of participating government, industrial and natural sites in fifteen visible and infrared spectral bands to provide a variety of image data associated with weapons production activities. The MTI satellite will have spatial resolution in the visible bands that is five times better than LANDSAT TM in each dimension and will have five thermal bands. In this work, the authors quantify the separability between specific materials and the natural background by applying Receiver Operating Curve (ROC) analysis to the residual errors from a linear unmixing. The authors apply the ROC analysis to quantify performance of the MTI. They describe the MTI imager and simulate its data by filtering HYDICE hyperspectral imagery both spatially and spectrally and by introducing atmospheric effects corresponding to the MTI satellite altitude. They compare and contrast the individual effects on performance of spectral resolution, spatial resolution, atmospheric corrections, and varying atmospheric conditions.