Publications

A telephone survey was conducted to evaluate the quality of service provided to the primary customers of the Corporate Ergonomics Group (CEG). One hundred clients who received services between October 1993 and June 1994 were asked questions on their expectations, implementation of ergonomic recommendations, follow-ups, time required, productivity improvements, symptom alleviation, and satisfaction. Suggestions on how processes could be improved were also solicited. In general, recommendations are being implemented, worksite evaluations are going smoothly, and customers are satisfied with the process. The CEG was pleased to learn that half of the people who implemented recommendations experienced improvements in productivity, and four out of five symptomatic customers experienced partial or complete relief. Through analysis of the data and by studying clients` suggestions for process improvement, the CEG has developed a strategy for changing and improving current procedures and practices. These plans can be found in the last section of this report.

The SERAPBIM (SEgmented RAil PHased Induction Motor) concept is a linear induction motor concept which uses rapidly-pulsed magnetic fields and a segmented reaction rail, as opposed to low-frequency fields and continuous reaction rails found in conventional linear induction motors. These improvements give a high-traction, compact, and efficient linear motor that has potential for advanced high speed rail propulsion. In the SERAPBIM concept, coils on the vehicle push against a segmented aluminum rail, which is mounted on the road bed. Current is pulsed as the coils cross an edge of the segmented rail, inducing surface currents which repel the coil. The coils must be pulsed in synchronization with the movement by reaction rail segments. This is provided by a sense-and-fire circuit that controls the pulsing of the power modulators. Experiments were conducted to demonstrate the feasibility of the pulsed induction motor and to collect data that could be used for scaling calculations. A 14.4 kg aluminum plate was accelerated down a 4 m track to speeds of over 15 m/sec with peak thrust up to 18 kN per coilset. For a trainset capable of 200 mph speed, the SERAPHIM concept design is based on coils which are each capable of producing up to 3.5 kN thrust, and 30 coil pairs are mounted on each power car. Two power cars, one at each end of the train, provide 6 MW from two gas turbine prime power units. The thrust is about 210.000 N and is essentially constant up to 200 km/hr since wheel slippage does not limit thrust as with conventional wheeled propulsion. A key component of the SERAPHIM concept is the use of passive wheel-on-rah support for the high speed vehicle. Standard steel wheels are capable of handling over 200 mph. The SERAPHIM cost is comparable to that for steel-wheel high-speed rail, and about 10% to 25% of the projected costs for a comparable Maglev system.

The Vital Issues Process, developed by the Sandia National Laboratories Strategic Technologies Department, was utilized by the Health Care Task Force Advisory Group to apply structure to their policy deliberations. By convening three expert panels, an overarching goal for the New Mexico health care system, seven desired outcomes, nine policy options, and 17 action items were developed for the New Mexico health care system. Three broadly stated evaluation criteria were articulated and used to produce relative rankings of the desired outcomes and policy options for preventive care and information systems. Reports summarizing the policy deliberations were submitted for consideration by the Health Care Task Force, a Joint Interim Committee of the New Mexico Legislature, charged with facilitating the development and implementation of a comprehensive health care delivery system for New Mexico. The Task Force reported its findings and recommendations to the Second Session of the 41st New Mexico State Legislature in January 1994.

The Automated Assembly Team of the APRIMED Project (abbreviated as A{prime}) consists of two parts: the Archimedes Project, which is an ongoing project developing automated assembly technology, and the A{prime} Robot Team. Archimedes is a second generation assembly planning system that both provides a general high-level assembly sequencing capability and, for a smaller class of products, facilitates automatic programming of a robotic workcell to assemble them. The A{prime} robot team designed, developed, and implemented a flexible robot workcell which served as the automated factory of the A{prime} project. In this document we briefly describe the role of automated assembly planning in agile manufacturing, and specifically describe the contributions of the Archimedes project and the A{prime} robot team to the A{prime} project. We introduce the concepts of the Archimedes automated assembly planning project, and discuss the enhancements to Archimedes which were developed in response to the needs of the A{prime} project. We also present the work of the A{prime} robot team in designing and developing the A{prime} robot workcell, including all tooling and programming to support assembly of the A{prime} discriminator devices. Finally, we discuss the process changes which these technologies have enabled in the A{prime} project.

This is a preliminary report of a multi-year collaboration of the authors addressing the subject: Can a facility be designed for team learning and would it improve the efficiency and effectiveness of team interactions? Team learning in this context is a broad definition that covers all activities where small to large groups of people come together to work, to learn, and to share through team activities. Multimedia, networking, such as World Wide Web and other tools, are greatly enhancing the capability of individual learning. This paper addresses the application of technology and design to facilitate group or team learning. Many organizational meetings need tens of people to come together to do work as a large group and then divide into smaller subgroups of five to ten to work and then to return and report and interact with the larger group. Current facilities were not, in general, designed for this type of meeting. Problems with current facilities are defined and a preliminary design solution to many of the identified problems is presented.

The results of previously completed vertical outcrop sampling transacts are summarized with respect to planning downhole sampling. The summary includes statistical descriptions and descriptions of the spatial variability of the sampled parameters. Descriptions are made on each individual transect, each thermal/mechanical unit and each previously defined geohydrologic unit. Correlations between parameters indicate that saturated hydraulic conductivity is not globally correlated to porosity. The correlation between porosity and saturated hydraulic conductivity is both spatially and lithologically dependent. Currently, there are not enough saturated hydraulic conductivity and sorptivity data to define relationships between these properties and porosity on a unit by unit basis. Also, the Prow Pass member of the Crater Flat Tuff and stratigraphically lower units have gone essentially unsampled in these outcrop transacts. The vertical correlation length for hydrologic properties is not constant across the area of the transacts. The average sample spacing within the transacts ranges from 1.25 to 2.1 meters. It appears that, with the exception of the Topopah Spring member units, a comparable sample spacing will give adequate results in the downhole sampling campaign even with the nonstationarity of the vertical correlation. The properties within the thermal/mechanical units and geohydrologic units of the Topopah Spring member appear to have a spatial correlation range less than or equal to the current sample spacing within these units. For the downhole sampling, a sample spacing of less than 1.0 meters may be necessary within these units.

This report describes the first practical, non-invasive technique for detecting and imaging currents internal to operating integrated circuits (ICs). This technique is based on magnetic force microscopy and was developed under Sandia National Laboratories` LDRD (Laboratory Directed Research and Development) program during FY 93 and FY 94. LDRD funds were also used to explore a related technique, charge force microscopy, for voltage probing of ICs. This report describes the technical work performed under this LDRD as well as the outcomes of the project in terms of publications and awards, intellectual property and licensing, synergistic work, potential future work, hiring of additional permanent staff, and benefits to DOE`s defense programs (DP).

Sandia National Laboratories has established a Cooperative Research and Development Agreement with consortium members of the National Center for Manufacturing Sciences (NCMS) to develop fundamental generic technology in the area of printed wiring board materials and surface finishes. Improved solderability of copper substrates is an important component of the Sandia-NCMS program. We are investigating the effects of surface roughness on the wettability and solderability behavior of several different types of copper board finishes. In this paper, we present roughness and solderability characterizations for a variety of chemically-etched copper substrates. Initial testing on six chemical etches demonstrate that surface roughness can be greatly enhanced through chemical etching. Noticeable improvements in solder wettability were observed to accompany increases in roughness. A number of different algorithms and measures of roughness were used to gain insight into surface morphologies that lead to improved solderability.

Sandia National Laboratories conducts the photovoltaic balance of systems (BOS) program, which is sponsored by the US Department of Energy`s Office of Energy Management. Under this program, SNL lets commercialization contracts and conducts a laboratory program designed to advance BOS technology, improve BOS component reliability, and reduce the BOS life-cycle-cost. This report details the testing of the first large US manufactured hybrid inverter and its associated maximum power tracker.

The overpressurization of a 1:6-scale reinforced concrete containment building demonstrated that liner tearing is a plausible failure mode in such structures under severe accident conditions. A combined experimental and analytical program was developed to determine the important parameters which affect liner tearing and to develop reasonably simple analytical methods for predicting when tearing will occur. Three sets of test specimens were designed to allow individual control over and investigation of the mechanisms believed to be important in causing failure of the liner plate. The series of tests investigated the effect on liner tearing produced by the anchorage system, the loading conditions, and the transition in thickness from the liner to the insert plate. Before testing, the specimens were analyzed using two- and three-dimensional finite element models. Based on the analysis, the failure mode and corresponding load conditions were predicted for each specimen. Test data and post-test examination of test specimens show mixed agreement with the analytical predictions with regard to failure mode and specimen response for most tests. Many similarities were also observed between the response of the liner in the 1:6-scale reinforced concrete containment model and the response of the test specimens. This work illustrates the fact that the failure mechanism of a reinforced concrete containment building can be greatly influenced by details of liner and anchorage system design. Further, it significantly increases the understanding of containment building response under severe conditions.

As part of an Environmentally Conscious Manufacturing (ECM) Program, a study was conducted at Sandia National Laboratories to identify an alternative cleaning process that would effectively replace trichloroethylene (TCE) for cleaning mechanical piece parts of Switch Tube assemblies. Eight aqueous alkaline cleaners, as well as an isopropyl alcohol and isopropyl alcohol/Cyclohexane cleaning process, were studied as potential replacements. Cleaning efficacy, materials compatibility, etch rate and corrosion studies were conducted and used to screen potential candidates. Cleaning efficacy was determined using visual examination, goniometer/contact angle measurements, Auger electron spectroscopy, X-ray Photoelectron spectroscopy and an evaporative rate analysis technique known as MESERAN Surface Analysis. Several cleaners were identified as potential replacements for TCE based solely on the cleaning efficacy results. Some of the cleaners, however, left undesirable residues studies were completed, Brulin 815GD (an aqueous alkaline cleaner) was selected as the replacement for TCE.

This paper describes the planning of evaluation for one large-scale national energy program with-scale, national energy program with international reporting requirements, US. Climate Change Action Plant. Referred to as Energy Partnerships for a Strong Economy, this program includes 19 DOE Office of Energy Efficiency and Renewable Energy (EE) initiatives and three other DOE projects. The evaluation strategy is to have a six year effort with ongoing performance measurement, market studies and process evaluations when deviations from targeted outcomes occur, and a final evaluation report that combines these results with other impact evaluations deemed necessary. The evaluation planning and implementation will use a collaborative approach involving program managers and stakeholders, including program partners and customers, to ensure that evaluation results are useful and utilized. Performance mapping will be used to describe the programs to be evaluated and determine data collection needs and key evaluation questions. The evaluation plan uses multiple evaluation methods, including model and engineering estimates, self-reporting by partners, case studies, surveys, and modified peer/expert review in order to accommodate the scope and diversity of programs and the need to measure progress as well as impact.

The part-load behavior of a typical 30-MWe SEGS (solar electric generating systems) plant was studied using a detailed thermodynamic model. As part of this analysis, a new solar field model was derived, based on measurement results of an LS-2 Collector and accounting for various conditions of receiver tubes, lost mirrors and measured reflectivity. A comparison was made of the model results to real plant conditions for a winter and summer day in order to test the accuracy of the model. The effects of bare tubes, different wind speeds, mirror reflectivity and other factors were studied showing, e.g., that heat losses due to wind are predicted to be very low. The comparison also shows that the model still lacks the capability to fully account for actual solar field conditions. The model was also compared to the SOLERGY model, showing differences between the assumptions used in both models. Finally different operating conditions of the plant were studied for a summer, fall, and winter day to provide a better understanding of how changing solar field outlet temperatures affect gross and net output of the plant. This clearly indicates that the lowest possible superheating temperature maximizes the gross electric output. On a net basis this conclusion is modified due to the high parasitics of the HTF (heat transfer fluid) pumps. It was found that the optimum operating strategy depends on the insolation conditions, e.g., different superheating temperatures should be chosen in summer, fall and winter. If the pressure drop in the solar field is reduced due to replacement of flex hoses with ball joints, increasing the HTF flow is more reasonable, so that at low isolation conditions the lowest possible superheating temperature also leads to the maximum net output.

The Energy Policy Act of 1992 required the DOE to develop recommendations and implement government programs to assist the domestic uranium industry in increasing export opportunities. In 1993, as part of that effort, the Office of Nuclear Energy identified several key factors that could (or have) significantly impact(ed) export opportunities for domestic uranium. This report addresses one of these factors: regulatory and policy impediments to the flow of uranium products between the US and other countries. It speaks primarily to the uranium market for civil nuclear power. Changes in the world political and economic order have changed US national security requirements, and the US uranium industry has found itself without the protected market it once enjoyed. An unlevel playing field for US uranium producers has resulted from a combination of geology, history, and a general US political philosophy of nonintervention that precludes the type of industrial policy practiced in other uranium-exporting countries. The US has also been hampered in its efforts to support the domestic uranium-producing industry by its own commitment to free and open global markets and by international agreements such as GATT and NAFTA. Several US policies, including the imposition of NRC fees and licensing costs and Harbor Maintenance fees, directly harm the competitiveness of the domestic uranium industry. Finally, requirements under US law, such as those in the 1979 Nuclear Nonproliferation Act, place very strict limits on the use of US-origin uranium, limitations not imposed by other uranium-producing countries. Export promotion and coordination are two areas in which the US can help the domestic uranium industry without violating existing trade agreements or other legal or policy constraints.

The fabrication of a prosthetic socket for a below-the-knee amputee requires knowledge of the underlying bone structure in order to provide pressure relief for sensitive areas and support for load bearing areas. The goal is to enable the residual limb to bear pressure with greater ease and utility. Conventional methods of prosthesis fabrication are based on limited knowledge about the patient`s underlying bone structure. A 3D ultrasound imaging system was developed at Sandia National Laboratories. The imaging system provides information about the location of the bones in the residual limb along with the shape of the skin surface. Computer assisted design (CAD) software can use this data to design prosthetic sockets for amputees. Ultrasound was selected as the imaging modality. A computer model was developed to analyze the effect of the various scanning parameters and to assist in the design of the overall system. The 3D ultrasound imaging system combines off-the-shelf technology for image capturing, custom hardware, and control and image processing software to generate two types of image data -- volumetric and planar. Both volumetric and planar images reveal definition of skin and bone geometry with planar images providing details on muscle fascial planes, muscle/fat interfaces, and blood vessel definition. The 3D ultrasound imaging system was tested on 9 unilateral below-the- knee amputees. Image data was acquired from both the sound limb and the residual limb. The imaging system was operated in both volumetric and planar formats. An x-ray CT (Computed Tomography) scan was performed on each amputee for comparison. Results of the test indicate beneficial use of ultrasound to generate databases for fabrication of prostheses at a lower cost and with better initial fit as compared to manually fabricated prostheses.

Combination glass electrodes were tested for determining H{sup +} concentrations in concentrated pure and mixed NaCl and Na{sub 2}SO{sub 4} solutions, as well as natural brine systems. NaCl, Na{sub 2}SO{sub 4}, and mixtures of NaCl and Na{sub 2}SO{sub 4} solutions were analyzed. Correction factors for estimating pC{sub H}{sup +} (negative logarithm of H{sup +} concentration) were determined from measured/observed pH values. Required Gran-type titrations were done with HCl and/or NaOH. The titration method is described and a step-by-step procedure provided; it has been used previously for determining pC{sub H}{sup +} values of synthetic chloride-dominated brines. Precautions are required to determine correction factors for electrolytes that react with H{sup +} or OH{sup {minus}} [sulfate brines for titration with acid; magnesium brines for titration with base because of precipitation of Mg(OH)2]. Correction factors A (pC{sub H}{sup +} = pH{sub ob} + A) from HCl titrations were similar to those from NaOH titrations where the concentration of free H{sup +} was calculated using a thermodynamic model. These values should be applicable to solns with a very large range in measured pH values (2 to 12). Because a large number of solns were titrated with HCl and the A values are similar for HCl and NaOH titrations, the A values for NaCl and Na2SO4 solns were fit as a function of molality to allow extrapolation. For NaCl solns 0 to 6.0 M, A can be obtained by multiplying the molality by 0.159. For Na2SO4 solns 0 to 2.0 M, the values of A can be obtained from (0.221 {minus} 0.549X + 0.201X{sup 2}), where X is the molality of Na{sub 2}SO{sub 4}. Orion-Ross electrode evaluations indicated that the A values did not differ significantly for different electrodes. Results suggest that the data in this report can be used to estimate A values for different NaCl and Na{sub 2}SO{sub 4} solns even for noncalibrated electrodes.

Asynchronous Transfer Mode (ATM) technology is currently receiving extensive attention in the computer networking arena. Many experts predict that ATM will be the future networking technology for both the Local Area Network (LAN) and the Wide Area Network (WAN). This paper presents the results of a collaboration between Sandia National Laboratories` Advanced Networking Department and Engineering Sciences Center to study the implementation of ATM in one of Sandia`s most heavily loaded production networks. The network consists of over 120 Sun Sparc 10s and 20s, two SparcCenter 2000s, a 12 node parallel IBM SP-2, and several other miscellaneous high-end workstations. The existing network was first characterized through extensive traffic measurements to better understand the capabilities and limitations of the existing network technologies and to provide a baseline for comparison to an ATM network. This characterization was used to select a subset of the network elements which would benefit most from conversion to the ATM technology. This subset was then converted to equipment based on the latest ATM standards. With direct OC-3c (155 Mbps) host connections for the workstations and the file and compute servers, we demonstrated as much as 122 Mbps throughput (memory-to-memory TCP/IP transfers) between endpoints. Flow control in the classical many-to-one client server environment was also investigated. Throughout all of our tests, the interaction of the user applications with the network technologies was documented and possible improvements were tested. The performance and reliability of the ATM network was compared to the original network to determine the benefits and liabilities of the ATM technology.

No abstract available.

A method to reduce nightly parasitic power consumption in a molten salt central receiver is discussed where salt is drained from the piping and heat tracing is turned off to allow the piping to cool to ambient overnight, then in the morning the pipes are filled while they are cold. Since the piping and areas of the receiver in a molten-nitrate salt central-receiver solar power plant must be electrically heated to maintain their temperatures above the nitrate salt freezing point (430{degrees}F, 221{degrees}C), considerable energy could be used to maintain such temperatures during nightly shut down and bad weather. Experiments and analyses have been conducted to investigate cold filling receiver panels and piping as a way of reducing parasitic electrical power consumption and increasing the availability of the plant. The two major concerns with cold filling are: (1) how far can the molten salt penetrate cold piping before freezing closed and (2) what thermal stresses develop during the associated thermal shock. Experiments and analysis are discussed.

Models for direct containment heating (DCH) in the CONTAIN code for severe accident analysis have been reviewed and a standard input prescription for their use has been defined. The code has been exercised against a large subset of the available DCH data base. Generally good agreement with the experimental results for containment pressurization ({Delta}P) and hydrogen generation has been obtained. Extensive sensitivity studies have been performed which permit assessment of many of the strengths and weaknesses of specific model features. These include models for debris transport and trapping, DCH heat transfer and chemistry, atmosphere-structure heat transfer, interactions between nonairborne debris and blowdown steam, potential effects of debris-water interactions, and hydrogen combustion under DCH conditions. Containment compartmentalization is an important DCH mitigator in the calculations, in agreement with experimental results. The CONTAIN model includes partially parametric treatments for some processes that are not well understood. The importance of the associated uncertainties depends upon the details of the DCH scenario being analyzed. Recommended sensitivity studies are summarized that allow the user to obtain a reasonable estimate of the uncertainties in the calculated results.

In this paper we study the question: How useful is randomization in speeding up Exclusive Write PRAM computations? Our results give further evidence that randomization is of limited use in these types of computations. First we examine a compaction problem on both the CREW and EREW PRAM models, and we present randomized lower bounds which match the best deterministic lower bounds known. (For the CREW PRAM model, the lower bound is asymptotically optimal.) These are the first non-trivial randomized lower bounds known for the compaction problem on these models. We show that our lower bounds also apply to the problem of approximate compaction. Next we examine the problem of computing boolean functions on the CREW PRAM model, and we present a randomized lower bound, which improves on the previous best randomized lower bound for many boolean functions, including the OR function. (The previous lower bounds for these functions were asymptotically optimal, but we improve the constant multiplicative factor.) We also give an alternate proof for the randomized lower bound on PARITY, which was already optimal to within a constant additive factor. Lastly, we give a randomized lower bound for integer merging on an EREW PRAM which matches the best deterministic lower bound known. In all our proofs, we use the Random Adversary method, which has previously only been used for proving lower bounds on models with Concurrent Write capabilities. Thus this paper also serves to illustrate the power and generality of this method for proving parallel randomized lower bounds.

The queue-read, queue-write (QRQW) parallel random access machine (PRAM) model is a shared memory model which allows concurrent reading and writing with a time cost proportional to the contention. This is designed to model currently available parallel machines more accurately than either the CRCW PRAM or EREW PRAM models. Many algorithmic results have been developed for the QRQW PRAM. However, the only lower bound results have been fairly simple reductions from lower bounds for other models, such as the EREW PRAM or the ``few-write`` CREW PRAM. Here we present a lower bound specific to the QRQW PRAM. This lower bound is on the problem of Linear Approximate Compaction (LAC), whose input consists of at most m marked items in an array of size n, and whose output consists of the rn marked items in an array of size 0(m). There is an O({radical}log n), expected time randomized algorithm for LAC on the QRQW PRAM. We prove a lower bound of {Omega}(log log log n) expected time for any randomized algorithm for LAC. This bound applies regardless of the number of processors and memory cells of the QRQW PRAM. The previous best lower bound was {Omega}(log* n) time, taken from the known lower bound for LAC on the CRCW PRAM.

SPH (Smoothed Particle Hydrodynamics) is a gridless Lagrangian technique which is appealing as a possible alternative to numerical techniques currently used to analyze high deformation impulsive loading events. In the present study, the SPH algorithm has been subjected to detailed testing and analysis to determine the feasibility of using PRONTO/SPH for the analysis of various types of underwater explosion problems involving fluid-structure and shock-structure interactions. Of particular interest are effects of bubble formation and collapse and the permanent deformation of thin walled structures due to these loadings. These are exceptionally difficult problems to model. Past attempts with various types of codes have not been satisfactory. Coupling SPH into the finite element code PRONTO represents a new approach to the problem. Results show that the method is well-suited for transmission of loads from underwater explosions to nearby structures, but the calculation of late time effects due to acceleration of gravity and bubble buoyancy will require additional development, and possibly coupling with implicit or incompressible methods. © 1995 Springer-Verlag.

The authors have characterized the pyrochlore-to-perovskite crystallization process in solution-derived Pb(Zr{sub 0.20}Ti{sub 0.80})O{sub 3} thin films on (100) MgO single crystal substrates. It has been determined that the perovskite phase nucleated preferentially at the film/MgO interface out of a nanocrystalline ({approx}100{angstrom} grains) pyrochlore matrix. During the early stages of the pyrochlore-to-perovskite conversion process, perovskite growth proceeded nearly isotropically from the substrate to form hemispherically shaped grains. Deviations from isotropic growth were shown to result from a growth dependence based on the crystallographic orientation of a growing perovskite grain relative to the orientations of pyrochlore grains being transformed. The volume change that occurs during the pyrochlore-to-perovskite transformation along with two-dimensional grain growth has been used to develop a mechanism for formation of porosity that commonly is concentrated in grain boundary regions.

Sandia National Laboratories has established a Cooperative Research and Development Agreement with consortium members of the National Center for Manufacturing Sciences (NCMS) to develop fundamental generic technology in the area of printed wiring board materials and surface finishes. Improved solderability of copper substrates is an important component of the Sandia-NCMS program. The authors are investigating the effects of surface roughness on the wettability and solderability behavior of several different types of copper board finishes. In this paper, the authors present roughness and solderability characterizations for a variety of chemically-etched copper substrates. Initial testing on six chemical etches demonstrate that surface roughness can be greatly enhanced through chemical etching. Noticeable improvements in solder wettability were observed to accompany increases in roughness. A number of different algorithms and measures of roughness were used to gain insight into surface morphologies that lead to improved solderability.