On May 19 and 20, 2003, thirty-some members of Sandia staff and management met to discuss the long-term connections between energy and national security. Three broad security topics were explored: I. Global and U.S. economic dependence on oil (and gas); II. Potential security implications of global climate change; and III. Vulnerabilities of the U.S. domestic energy infrastructure. This report, rather than being a transcript of the workshop, represents a synthesis of background information used in the workshop, ideas that emerged in the discussions, and ex post facto analysis of the discussions. Each of the three subjects discussed at this workshop has significant U.S. national security implications. Each has substantial technology components. Each appears a legitimate area of concern for a national security laboratory with relevant technology capabilities. For the laboratory to play a meaningful role in contributing to solutions to national problems such as these, it needs to understand the political, economic, and social environments in which it expects its work to be accepted and used. In addition, it should be noted that the problems of oil dependency and climate change are not amenable to solution by the policies of any one nation--even the one that is currently the largest single energy consumer. Therefore, views, concerns, policies, and plans of other countries will do much to determine which solutions might work and which might not.
Biomanufacturing has the potential to be one of the defining technologies in the upcoming century. Research, development, and applications in the fields of biotechnology, bioengineering, biodetection, biomaterials, biocomputation and bioenergy will have dramatic impact on both the products we are able to create, and the ways in which we create them. In this report, we examine current research trends in biotechnology, identify key areas where biomanufacturing will likely be a major contributing field, and report on recent developments and barriers to progress in key areas.
This report summarizes the results obtained from a Laboratory Directed Research & Development (LDRD) project entitled 'Investigation of Potential Applications of Self-Assembled Nanostructured Materials in Nuclear Waste Management'. The objectives of this project are to (1) provide a mechanistic understanding of the control of nanometer-scale structures on the ion sorption capability of materials and (2) develop appropriate engineering approaches to improving material properties based on such an understanding.
An understanding of the dynamics of z-pinch wire array explosion and collapse is of critical interest to the development and future of pulsed power inertial confinement fusion experiments. Experimental results clearly show the extreme three-dimensional nature of the wire explosion and collapse process. The physics of this process can be approximated by the resistive magnetohydrodynamic (MHD) equations augmented by thermal and radiative transport modeling. Z-pinch MHD physics is dominated by material regions whose conductivity properties vary drastically as material passes from solid through melt into plasma regimes. At the same time void regions between the wires are modeled as regions of very low conductivity. This challenging physical situation requires a sophisticated three-dimensional modeling approach matched by sufficient computational resources to make progress in predictive modeling and improved physical understanding.
Two sorbents, zirconium coated zeolite and magnesium hydroxide, were tested for their effectiveness in removing arsenic from Albuquerque municipal water. Results for the zirconium coated zeolite indicate that phosphate present in the water interfered with the sorption of arsenic. Additionally, there was a large quantity of iron and copper present in the water, corrosion products from the piping system, which may have interfered with the uptake of arsenic by the sorbent. Magnesium hydroxide has also been proven to be a strong sorbent for arsenic as well as other metals. Carbonate, present in water, has been shown to interfere with the sorption of arsenic by reacting with the magnesium hydroxide to form magnesium carbonate. The reaction mechanism was investigated by FT-IR and shows that hydrogen bonding between an oxygen on the arsenic species and a hydrogen on the Mg(OH)2 is most likely the mechanism of sorption. This was also confirmed by RAMAN spectroscopy and XRD. Technetium exists in multiple oxidation states (IV and VII) and is easily oxidized from the relatively insoluble Tc(IV) form to the highly water soluble and mobile Tc(VII) form. The two oxidation states exhibit different sorption characteristics. Tc(VII) does not sorb to most materials whereas Tc(IV) will strongly sorb to many materials. Therefore, it was determined that it is necessary to first reduce the Tc (using SnCl2) before sorption to stabilize Tc in the environment. Additionally, the effect of carbonate and phosphate on the sorption of technetium by hydroxyapatite was studied and indicated that both have a significant effect on reducing Tc sorption.
This article describes how features of event tree analysis and Monte Carlo-based discrete event simulation can be combined with concepts from object-oriented analysis to develop a new risk assessment methodology, with some of the best features of each. The resultant object-based event scenario tree (OBEST) methodology enables an analyst to rapidly construct realistic models for scenarios for which an a priori discovery of event ordering is either cumbersome or impossible. Each scenario produced by OBEST is automatically associated with a likelihood estimate because probabilistic branching is integral to the object model definition. The OBEST methodology is then applied to an aviation safety problem that considers mechanisms by which an aircraft might become involved in a runway incursion incident. The resulting OBEST model demonstrates how a close link between human reliability analysis and probabilistic risk assessment methods can provide important insights into aviation safety phenomenology.
An efficient polymer mass loss and foam response model has been developed to predict the behavior of unconfined polyurethane foam exposed to fire-like heat fluxes. The mass loss model is based on a simple two-step mechanism using distributed reaction rates. The mass loss model was implemented into a multidimensional finite element heat conduction code that supports chemical kinetics and dynamic enclosure radiation. A discretization bias correction model was parameterized using elements with characteristic lengths ranging from 0.1 cm to 1 cm. Bias corrected solutions with these large elements gave essentially the same results as grid-independent solutions using 0.01-cm elements. Predictions were compared to measured decomposition front locations determined from real-time X-rays of 9-cm diameter, 15-cm tall cylinders of foam that were heated with lamps. The calculated and measured locations of the decomposition fronts were well within 1 cm of each other and in some cases the fronts coincided.
Combining broad-beam circuit level single-event upset (SEU) response with heavy ion microprobe charge collection measurements on single silicon-germanium heterojunction bipolar transistors improves understanding of the charge collection mechanisms responsible for SEU response of digital SiGe HBT technology. This new understanding of the SEU mechanisms shows that the right rectangular parallele-piped model for the sensitive volume is not applicable to this technology. A new first-order physical model is proposed and calibrated with moderate success.
For several years, Sandia National Laboratories and Lawrence Livermore National Laboratory have been part of a consortium funded by the Department of Energy to improve fuel efficiency of heavy vehicles such as Class 8 trucks through aerodynamic drag reduction. The objective of this work is to demonstrate the feasibility of using the steady Reynolds-Averaged Navier-Stokes (RANS) approach to predict the flow field around heavy vehicles, with special emphasis on the base region of the trailer, and to compute the aerodynamic forces. In particular, Sandia's computational fluid dynamics code, SACCARA, was used to simulate the flow on a simplified model of a tractor-trailer vehicle. The results are presented and compared with NASA Ames experimental data to assess the predictive capability of RANS to model the flow field and predict the aerodynamic forces.
Vulnerability analysis studies show that one of the worst threats against a facility is that of an active insider during an emergency evacuation. When a criticality or other emergency alarm occurs, employees immediately proceed along evacuation routes to designated areas. Procedures are then implemented to account for all material, classified parts, etc. The 3-Dimensional Video Motion Detection (3DVMD) technology could be used to detect and track possible insider activities during alarm situations, as just described, as well as during normal operating conditions. The 3DVMD technology uses multiple cameras to create 3-dimensional detection volumes or zones. Movement throughout detection zones is tracked and high-level information, such as the number of people and their direction of motion, is extracted. In the described alarm scenario, deviances of evacuation procedures taken by an individual could be immediately detected and relayed to a central alarm station. The insider could be tracked and any protected items removed from the area could be flagged. The 3DVMD technology could also be used to monitor such items as machines that are used to build classified parts. During an alarm, detections could be made if items were removed from the machine. Overall, the use of 3DVMD technology during emergency evacuations would help to prevent the loss of classified items and would speed recovery from emergency situations. Further security could also be added by analyzing tracked behavior (motion) as it corresponds to predicted behavior, e.g., behavior corresponding with the execution of required procedures. This information would be valuable for detecting a possible insider not only during emergency situations, but also during times of normal operation.
The state-of-the-art of inertial micro-sensors (gyroscopes and accelerometers) has advanced to the point where they are displacing the more traditional sensors in many size, power, and/or cost-sensitive applications. A factor limiting the range of application of inertial micro-sensors has been their relatively poor bias stability. The incorporation of an integral sensitive axis rotation capability would enable bias mitigation through proven techniques such as indexing, and foster the use of inertial micro-sensors in more accuracy-sensitive applications. Fabricating the integral rotation mechanism in MEMS technology would minimize the penalties associated with incorporation of this capability, and preserve the inherent advantages of inertial micro-sensors.
This paper presents the development of a two-stage pulse tube cooler for space applications. The staged cooler incorporates an integral High Efficiency Cryocooler (HEC) pulse tube cooler with a linear cold head and a split second remote coaxial cold head. The two-stage cold head was designed to provide simultaneous large cooling power at 95 K at the linear cold head and 180 K at the split coaxial cold head. The innovative staging design allows up to 50 cm of separation between the cold heads. The cooler is compatible with the existing HEC flight electronics.
How can information required for the proper functioning of a cell, an organism, or a species be transmitted in an error-introducing environment? Clearly, similar to engineering communication systems, biological systems must incorporate error control in their information transmissino processes. if genetic information in the DNA sequence is encoded in a manner similar to error control encoding, the received sequence, the messenger RNA (mRNA) can be analyzed using coding theory principles. This work explores potential parallels between engineering communication systems and the central dogma of genetics and presents a coding theory approach to modeling the process of protein translation initiation. The messenger RNA is viewed as a noisy encoded sequence and the ribosoe as an error control decoder. Decoding models based on chemical and biological characteristics of the ribosome and the ribosome binding site of the mRNA are developed and results of applying the models to the Escherichia coli K-12 are presented.
This report provides a summary of the three-year LDRD (Laboratory Directed Research and Development) project aimed at developing microchemical sensors for continuous, in-situ monitoring of volatile organic compounds. A chemiresistor sensor array was integrated with a unique, waterproof housing that allows the sensors to be operated in a variety of media including air, soil, and water. Numerous tests were performed to evaluate and improve the sensitivity, stability, and discriminatory capabilities of the chemiresistors. Field tests were conducted in California, Nevada, and New Mexico to further test and develop the sensors in actual environments within integrated monitoring systems. The field tests addressed issues regarding data acquisition, telemetry, power requirements, data processing, and other engineering requirements. Significant advances were made in the areas of polymer optimization, packaging, data analysis, discrimination, design, and information dissemination (e.g., real-time web posting of data; see www.sandia.gov/sensor). This project has stimulated significant interest among commercial and academic institutions. A CRADA (Cooperative Research and Development Agreement) was initiated in FY03 to investigate manufacturing methods, and a Work for Others contract was established between Sandia and Edwards Air Force Base for FY02-FY04. Funding was also obtained from DOE as part of their Advanced Monitoring Systems Initiative program from FY01 to FY03, and a DOE EMSP contract was awarded jointly to Sandia and INEEL for FY04-FY06. Contracts were also established for collaborative research with Brigham Young University to further evaluate, understand, and improve the performance of the chemiresistor sensors.
Battery life is an important, yet technically challenging, issue for battery development and application. Adequately estimating battery life requires a significant amount of testing and modeling effort to validate the results. Integrated battery testing and modeling is quite feasible today to simulate battery performance, and therefore applicable to predict its life. A relatively simple equivalent-circuit model (ECM) is used in this work to show that such an integrated approach can actually lead to a high-fidelity simulation of a lithium-ion cell's performance and life. The methodology to model the cell's capacity fade during thermal aging is described to illustrate its applicability to battery calendar life prediction.
This paper describes a methodology for implementing disk-less cluster systems using the Network File System (NFS) that scales to thousands of nodes. This method has been successfully deployed and is currently in use on several production systems at Sandia National Labs. This paper will outline our methodology and implementation, discuss hardware and software considerations in detail and present cluster configurations with performance numbers for various management operations like booting.
A new capability for modeling thin-shell structures within the coupled Euler-Lagrange code, Zapotec, is under development. The new algorithm creates an artificial material interface for the Eulerian portion of the problem by expanding a Lagrangian shell element such that it has an effective thickness that spans one or more Eulerian cells. The algorithm implementation is discussed along with several examples involving blast loading on plates.
The potential of a new cable diagnostic known as Pulse-Arrested Spark Discharge technique (PASD) is being studied. Previous reports have documented the capability of the technique to locate cable failures using a short high voltage pulse. This report will investigate the impact of PASD on the sample under test. In this report, two different energy deposition experiments are discussed. These experiments include the PASD pulse ({approx}6 mJ) and a high energy discharge ({approx}600 mJ) produced from a charged capacitor source. The high energy experiment is used to inflict detectable damage upon the insulators and to make comparisons with the effects of the low energy PASD pulse. Insulator breakdown voltage strength before and after application of the PASD pulse and high energy discharges are compared. Results indicate that the PASD technique does not appear to degrade the breakdown strength of the insulator or to produce visible damage. However, testing of the additional materials, including connector insulators, may be warranted to verify PASDs non-destructive nature across the full spectrum of insulators used in commercial aircraft wiring systems.