Dip coating is the primary means of depositing sol-gel films for precision optical coatings. Sols are typically multicomponent systems consisting of an inorganic phase dispersed in a solvent mixture, with each component differing in volatility and surface tension. This, together with slow coating speeds (<1cm/s), makes analysis of the coating process complicated; unlike most high-speed coating methods, solvent evaporation, evolving rheology, and surface tension gradients alter significantly the fluid mechanics of the deposition stage. We set out to understand these phenomena with computer-aided predictions of the flow and species transport fields. The underlying theory involves mass, momentum, and species transport on a domain of unknown shape, with models and constitutive equations for vapor-liquid equilibria and surface tension. Due accounting is made for the unknown position of the free surface, which locates according to the capillary hydrodynamic forces and solvent loss by evaporation. Predictions of the effects of mass transfer, hydrodynamics, and surface tension gradients on final film thickness are compared with ellipsometry measurements of film thickness on a laboratory pilot coater. Although quantitative agreement is still lacking, both experiment and theory reveal that the film profile near the drying line takes on a parabolic shape. 2 refs., 2 figs.
Sandia National Laboratories is a multiprogram engineering laboratory that serves the nation through the Department of Energy (DOE), both in its programs and those of other agencies. Major research and development responsibilities cover nuclear weapons, arms control, energy, environment and other areas of strategic importance to national security. The principal mission is to support national defense policies by ensuring that the nuclear weapon stockpile meets the highest standards of safety, security, control and military performance. In May of 1968, the Albuquerque Office of DOE (then AEC) assigned the Quality Assurance function to Sandia Laboratories on all products for which Sandia has design responsibility. The Sandia Quality Improvement Plan presents a Quality Management System that integrates the Sandia quality policies and several independent improvement processes into a cohesive structure. This structure guides day-to-day operations toward strategic objectives. The Sandia Quality Policy provides the underlying principles for the management of our research and engineering efforts and establishes our customers as the central focus of our Sandia quality improvement efforts. Operationally, these efforts are centered around quality improvement processes based on good management practices developed by AT T, and progress is measured against the Malcolm Baldridge National Quality Award criteria. Developing a comprehensive plan based on these processes requires that we determine where we are, where we want to be, and how we measure our progress. 1 fig. (JF)
A review of the objectives and accomplishments of the Computational Benchmark Problem Committee (CBPC) of the American Nuclear Society Mathematics and Computation Division is presented. A list of the benchmark problems compiled by the CBPC and published by the Argonne Code Center is included, along with a list of the problems currently under review. A brief discussion of the challenge of benchmarking in the current environment of rapidly evolving computing technology is given. 20 refs., 3 tabs.
The Distant Light Program sponsored by the Defense Nuclear Agency (RAEE) is directed toward understanding the response of electronic systems to Source Region EMP (SREMP) and will result in the development of proven system hardening and validation techniques for SREMP. This program relies very strongly on testing in above ground test (AGT) simulators such as the HERMES III gamma ray simulator at Sandia National Laboratories in Albuquerque, New Mexico. This paper describes theoretical and experimental efforts aimed at understanding the gamma ray flux produced by HERMES III in terms of its time dependence, spatial variation and spectrum. As part of this characterization, the calibration of various measuring devices must be considered. This paper describes the progress made in characterizing the HERMES III radiation output through December of 1990.
Promoted iron catalysts are commonly used for Fischer-Tropsch (F-T) synthesis. Copper, potassium and silica are frequently employed as promoter species, either singly or in combination. The number of different iron catalyst formulations which have been investigated for F-T synthesis is enormous and there does not yet appear to be a general consensus as to the optimum catalyst composition. In addition, questions regarding the effects of variations in catalyst activation and reaction conditions are still open. Because of the large number of parameters involved in the development of F-T catalysts, a great deal of work remains to be done before the factors affecting catalyst performance are fully understood. In this paper one of these factors, namely the effects of variations in activation procedure on the surface composition of iron based F-T catalysts, will be investigated. Two different catalysts were studied. The first catalyst, with a composition of 100 Fe/5 Cu/4.2 K/25 SiO{sub 2} (parts by weight) whose little variation in activity procedure (1). The second catalyst (100 Fe/3 Cu/0.2 K) displays wide variations in activity with activation procedure (2). Surface compositions of these two catalysts were measured, after the activation treatments described above, using Auger electron spectroscopy (AES). It will be shown that the variations in catalyst activity observed by Bukur, et al. (1,2), correlate well with variations in surface composition, offering insights into the optimum conditions for catalyst activation. 9 refs., 6 figs.
An analysis is made of the experimental results of a minimum-time trajectory control scheme for a two-link flexible robot. An offline optimization routine determines a minimum-time, straight-line tip trajectory which stays within the torque constraints of the motors and ends with no vibrational transients. An efficient finite-element model is used in the optimization to approximate the flexible arm dynamics. The control strategy described is used to determine the feedback gains for the position, velocity, and strain gage signals from a quadratic cost criterion based on the finite-element model linearized about the straight-line tip trajectory. These feedback signals are added to the modeled torque values obtained from the optimization routine and used to control the robot arm actuators. The results indicate that this combination of model-based and error-driven control strategies achieves a closer tracking of the desired trajectory and a better handling of modeling errors than either strategy alone.
Lithium batteries have been used in a variety of applications for a number of years. As their use continues to grow, particularly in the consumer market, a greater emphasis needs to be placed on safety and reliability. There is a useful technique which can help to design cells and batteries having a greater degree of safety and higher reliability. This technique, known as fault tree analysis, can also be useful in determining the cause of unsafe behavior and poor reliability in existing designs.
During 1990, Sandia National Laboratories initiated an advanced lead-acid battery development program supported by the US Department of Energy's Office of Energy Management. The goal is to develop a low maintenance, cost effective battery by the mid- to late 1990's that is tailored to a variety of electric utility applications. Several parallel activities are being pursued to achieve this goal. One activity seeks to quantify the economic benefits of battery storage for specific cases in candidate utility systems and identify opportunities for field demonstration of battery systems at electric utility and utility customer sites. Such demonstrations will not only generate valuable operating experience data, but will also help in building user confidence in battery storage systems. Other activities concentrate on cell- and battery-level research and development aimed at overcoming shortcomings in existing technologies, such as Valve-Regulated Lead-Acid (VRLA), or, sealed lead-acid batteries.
A panel research experiment (PRE) was designed, built, and tested as a scaled-down model of a direct absorption receiver (DAR). The PRE is a 3-MWt DAR experiment that will allow flow testing with molten nitrate salt and provide a test bed for DAR testing with actual solar heating. In a solar central receiver system DAR, the heat absorbing fluid (a blackened molten nitrate salt) flows in a thin film down a vertical panel (rather than through tubes as in conventional receiver designs) and absorbs the concentrated solar flux directly. The ability of the flowing salt film to absorb the incident solar flux depends on the panel design, hydraulic and thermal fluid flow characteristics, and fluid blackener properties. Testing of the PRE is being conducted to demonstrate the engineering feasibility of the DAR concept. The DAR concept is being investigated because it offers numerous potential performance and economic advantages for production of electricity when compared to other solar receiver designs. The PRE utilized a 1-m wide by 6-m long absorber panel. The salt flow tests are being used to investigate component performance, panel deformations, and fluid stability. Salt flow testing has demonstrated that all the DAR components work as designed and that there are fluid stability issues that need to be addressed. Future solar testing will include steady-state and transient experiments, thermal loss measurements, responses to severe flux and temperature gradients and determination of peak flux capability, and optimized operation. In this paper, we describe the design, construction, and some preliminary flow test results of the Panel Research Experiment.
This study was undertaken in order to document and analyze the unique set of data on subsurface fracture characteristics, especially spacing, provided by the US Department of Energy's Slant Hole Completion Test well (SHCT-1) in the Piceance Basin, Colorado. Two hundred thirty-six (236) ft (71.9 m) of slant core and 115 ft (35.1 m) of horizontal core show irregular, but remarkably close, spacings for 72 natural fractures cored in sandstone reservoirs of the Mesaverde Group. Over 4200 ft (1280 m) of vertical core (containing 275 fractures) from the vertical Multiwell Experiment wells at the same location provide valuable information on fracture orientation, termination, and height, but only data from the SHCT-1 core allow calculations of relative fracture spacing. Within the 162-ft (49-m) thick zone of overlapping core from the vertical and deviated wellbores, only one fracture is present in vertical core whereas 52 fractures occur in the equivalent SHCT-1 core. The irregular distribution of regional-type fractures in these heterogeneous reservoirs suggests that measurements of average fracture spacing'' are of questionable value as direct input parameters into reservoir engineering models. Rather, deviated core provides data on the relative degree of fracturing, and confirms that cross fractures can be rare in the subsurface. 13 refs., 11 figs.
Current computer network protocols are very robust and capable of being used in a variety of different environments. Typically, the implementations of these protocols come to the user with preset parameters that provide reasonable performance for low delay- bandwidth product environments with low error rates, but these defaults do not necessarily provide optimal performance for high delay-bandwidth, high error rate environments. To provide optimal performance from the user's perspective, which is application to application, all equivalent layers of the protocol must be tuned. The key to tuning protocols is reducing idle time on the links caused by various protocol layers waiting for acknowledgments. The circuit bandwidth, propagation delay, error rate, number of outstanding packets, buffer length, number of buffers, and buffer size can all affect the observed idle time. Experiments have been conducted on test bed systems, and on live satellite and terrestrial circuits. Observations from these experiments led the authors to draw conclusions about the locations of common bottlenecks. Various aspects of network tuning and certain specific issues relating to the tuning of three protocols (DECnet, TCP/IP, NETEX) over various media types (point-to-point and broadcast) under several different conditions (terrestrial and satellite) are examined in this paper. Also described are the lessons learned about protocol and network tuning. 3 refs., 2 tabs.
A comparison of the short-transverse SCC behavior of 2090 in pH 5.5 Cl{sup {minus}} and alkaline CO{sub 3}{sup 2 {minus}}/Cl{sup {minus}} solutions using a static load smooth bar SCC technique was made. In the alkaline CO{sub 3}{sup 2 {minus}}/Cl{sup {minus}} solutions, E{sub br} for the {alpha}-Al matrix phase was 0.130 V more positive than the E{sub br} of the subgrain boundary T{sub 1} phase. In this environment, stress corrosion cracking test specimens subjected to potentials in the window defined by the two breakaway potentials failed along an intersubgranular path in less than an hour. In the Cl{sup {minus}} environment, the E{sub br} values for the two phases were nearly equal and this rapid SCC condition could not be satisfied; accordingly SCC failures were not observed. Rapid SCC failure of 2090 in CO{sub 3}{sup 2 {minus}}/Cl{sup {minus}} in our static load, constant immersion experiments appear to be related to recently reported pre-exposure embrittlement'' failures induced by immersing stressed specimens removed into ambient laboratory air after immersion in aerated NaCl solution for 7 days. In those experiments, specimens failed in less than 24 hours after removal from solution. Our polarization experiments have shown that the corrosion behavior of T{sub 1}, CO{sub 3}{sup 2 {minus}}/Cl{sup {minus}} environments, but the {alpha}-Al phase crack walls, is rapidly passivated. X-ray diffraction of the films which formed in simulated crevices suggests that this passivating film belongs to a class of compounds known as hydrotalcites.
Vertical axis wind turbine (VAWT) technology in the United States started in the early 1970s directly from the original work in Canada. The close, and very productive relationships among laboratories, universities and industry have continued since that time. This paper briefly discusses the significant technical progress and rather dramatic programmatic changes that have occurred in the past 18 to 24 months on the US side of the border. 20 refs., 14 figs.
Numerous small-scale in situ seal experiments have been emplaced in boreholes up to 38 in. in diameter at the WIPP. Seal materials include expansive salt concrete, bentonite, and crushed salt. Emplacement techniques stressed conventional technology and the use of available site personnel. Preliminary evaluation of the performance of these seals has been completed by using structural data from embedded instrumentation and fluid flow data from gas and brine flow measurements. Preliminary results suggest that submicrodarcy permeabilities can be obtained using these materials and that structural performance is satisfactory. 17 refs., 3 figs., 1 tab.
This paper describes a formal process for selecting, from a diverse set of proposed waste minimization activities, those activities that provide the greatest benefit to DOE. A methodology for evaluating and prioritizing proposals was developed to illustrate how the selection process works and what types of data are required to characterize waste minimization activities. It is clearly impossible to remove all aspects of subjective judgment from the proposal selection process. With this important consideration in mind, the methodology presented is put forth to enhance, not replace, the traditional DOE decision-making process. With relatively minor refinements, this methodology can be immediately useful to DOE Environmental Restoration and Waste Management and Defense Program organizations in preparing, evaluating, and prioritizing waste minimization proposals. 7 refs., 1 tab., 2 figs.
Our primary purpose in this test is to provide a brief general description of a few applications of various electrophoretic systems which have been investigated and have found use in various coating applications at Sandia National Laboratories. Both organic and inorganic suspensions in aqueous and non-aqueous media have been considered in these studies. Applications include high voltage insulating dielectrics, thermally conductive/electrically insulating films, adherent lubricating films, uniform photoresist films, glass coatings, and fissile uranium oxide/carbon composite films for studies of nuclear powered lasers. More recently, we have become interested in the beneficial environmental aspects of being able to provide protective polymer coatings which reduce or minimize the use of organic solvents required by traditional spray coat processes. Important practical factors which relate to film uniformity, adhesion, and composition are related to unique coating or plating capabilities and applications. 6 refs., 2 figs., 1 tab.
System dynamicists frequently encounter signals they interpret as realizations of normal random processes. To simulate these analytically and in the laboratory they use methods that yield approximately normal random signals. The traditional digital methods for generating such signals have been developed during the past 25 years. During the same period of time much development has been done in the theory of chaotic processes. The conditions under which chaos occurs have been studied, and several measures of the nature of chaotic processes have been developed. Some of the measures used to characterize the nature of dynamic system motions are common to the study of both random vibrations and chaotic processes. This paper considers chaotic processes and random vibrations. It shows contrasts between the two and situations where they are indistinguishable. The applicability of the Central Limit Theorem to chaotic processes is demonstrated. 12 refs., 8 figs.
A knowledge of the short term creep rupture behavior of Tantalum alloy T-111 is necessary to predict device integrity in the heat source section of Radioisotope Thermoelectric Generators (RTG's) at the end of service life, in the event of a fuel fire. High pressures exist in RTG's near the end of service life, these are caused by gas generation resulting from radioactive decay of the nuclear fuel. The internal pressure exerts a significant hoop stress on the T-111 alloy structural containment member. This paper analyses the short term creep behavior (rupture times up to {approximately}2 {times} 10{sup 3} hrs.) of cold worked (CW) T-111 alloy, using the existing data of Stephenson (1967). Corellations for the time to rupture, time to 1% strain and minimum creep rate have been obtained from this data using multivariable linear regression analysis. These results are compared to other short term rupture data for T-111 alloy. Finally, at the stress/temperature levels relevant to the RTG fuel fire scenario near the end of service life, the rupture time correlation for T-111 alloy predicts a rupture time of approximately 100 hrs. 10 refs., 3 figs., 1 tab.
Before the Waste Isolation Pilot Plant (WIPP) may begin service as the United States' first repository for the permanent disposal of transuranic (TRU) radioactive waste, the Department of Energy (DOE) must establish compliance with applicable environmental and safety regulations. This paper addresses one major regulation, the United States Environmental Protection Agency's (EPA) Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes, hereafter referred to as the Standard. The paper does not address compliance with other regulations. This paper summarizes Sandia National Laboratories' (SNL) early-1990 understanding of the WIPP Project's ability to comply with the long-term performance requirements set by Subpart B of the Standard, the Environmental Standards for Disposal. It also reviews the current understanding of questions critically affecting compliance and outlines the options available to assure that radionuclide releases will remain within regulatory limits. 10 refs., 3 figs.
A computational fluids dynamics scheme is presented to solve the unsteady Thin-Layer Navier-Stokes (TLNS) equations over a blunt body at high altitude, high Mach number atmospheric reentry flow conditions. This continuum approach is directed to low density hypersonic flows by accounting for non-zero bulk viscosity effects in near frozen flow conditions. The TLNS equations are solved over an axisymmetric body at zero incidence relative to the free stream. The time dependent axisymmetric governing equations are transformed into a computational plane, then cast into weak conservative form and solved using a first-order fully implicit scheme in time with second-order flux vector splitting for spatial derivatives. The physical domain is defined over representative sphere and sphere/cone geometries using a body-fitted clustered algebraic grid within a fixed domain (i.e., shock capturing). At the present time, nonequilibrium thermo-chemistry effects are not modeled. Catalytic wall, ionization and radiation effects are also excluded from the current analysis. However, the significant difference from previous studies is the inclusion of the capability to model non-zero bulk viscosity effects. The importance of bulk viscosity is reviewed and blunt body flow field solutions are presented to illustrate the potential contribution of this phenomena at high altitude hypersonic conditions. The current technique is compared with experimental data and other approximate continuum solutions. A variety of test cases are also presented for a wide range of free stream Mach conditions. 18 refs., 42 figs.
An obvious group of applications for HTS materials is microwave and millimeter wave circuitry. Besides low loss, the unique features of these materials, such as flux flow, can be exploited. We have been concentrating on the Tl-Ca-Ba-Cu-O family of materials. The film growth techniques, lithographic processing methods and the characteristics of several devices we have developed will be presented. These devices include a flux flow-based transistor with demonstrated operation at over 35 GHz, real gain in a 50 ω system and potentially useful non-linearities and impedance levels. A number of passive microwave components are under investigation to form a more complete HTS microwave technology group.
An advanced Synthetic Aperture Radar Motion Compensation System has been developed by Sandia National Laboratories (SNL). The system includes a miniaturized high accuracy ring laser gyro inertial measurement unit, a three axis gimbal pointing and stabilization assembly, a differential Global Positioning System (GPS) navigation aiding system, and a pilot guidance system. The system provides several improvements over previous SNL motion compensation systems and is capable of antenna stabilization to less than 0.01 degrees RMS and absolute position measurement to less than 5.0 meters RMS. These accuracies have been demonstrated in recent flight testing aboard a DHC-6-300 Twin Otter'' aircraft.
As part of the Yucca Mountain Project, our research program to develop and validate conceptual models for flow and transport through unsaturated fractured rock integrates fundamental physical experimentation with conceptual model formulation and mathematical modeling. Our research is directed toward developing and validating macroscopic, continuum-based models and supporting effective property models because of their widespread utility within the context of this project. Success relative to the development and validation of effective property models is predicted on a firm understanding of the basic physics governing flow through fractured media, specifically in the areas of unsaturated flow and transport in a single fracture and fracture-matrix interaction.
Construction of well-posed scenarios for the range of conditions possible at any proposed repository site is a critical first step to assessing total system performance. Event tree construction is the method that is being used to develop potential failure scenarios for the proposed nuclear waste repository at Yucca Mountain. An event tree begins with an initial event or condition. Subsequent events are listed in a sequence, leading eventually to release of radionuclides to the accessible environment. Ensuring the validity of the scenarios requires iteration between problems constructed using scenarios contained in the event tree sequence, experimental results, and numerical analyses. Details not adequately captured within the tree initially may become more apparent as a result of analyses. To illustrate this process, we discuss the iterations used to develop numerical analyses for PACE-90 using basaltic igneous activity and human-intrusion event trees.
Yucca Mountain, located in southwestern Nevada, is the site for a proposed high-level nuclear waste repository. The hydrologic units at Yucca Mountain appear to have quite different material characteristics. Additionally, measurements show that the material properties within each hydrologic unit vary significantly. Rock core samples taken from this site indicate that the volcanic tuff is highly fractured and nonhomogeneous. Modeling studies were conducted to determine the effects of material heterogeneities on the flow of water through rock. Multiple numerical calculations were made using random variations in spatial distributions of material properties. The results of these material variations on flow resistance, mechanical dispersion, and channeling were determined. Computed results were compared with a linear analytical model. Good agreement was obtained in the majority of the flow cases investigated.
Under the sponsorship of the US Nuclear Regulatory Commission (NRC), Sandia National Laboratories (SNL) is developing a performance assessment methodology for the analysis of long-term disposal and isolation of high-level nuclear wastes (HLW) in alternative geologic media. As part of this exercise, SNL created a conceptualization of ground-water flow and radionuclide transport in the far field of a hypothetical HLW repository site located in unsaturated, fractured tuff formations. This study provides a foundation for the development of conceptual mathematical, and numerical models to be used in this performance assessment methodology. This conceptualization is site specific in terms of geometry, the regional ground-water flow system, stratigraphy, and structure in that these are based on information from Yucca Mountain located on the Nevada Test Site. However, in terms of processes in unsaturated, fractured, porous media, the model is generic. This report also provides a review and evaluation of previously proposed conceptual models of unsaturated and saturated flow and solute transport. This report provides a qualitative description of a hypothetical HLW repository site in fractured tuff. However, evaluation of the current knowledge of flow and transport at Yucca Mountain does not yield a single conceptual model. Instead, multiple conceptual models are possible given the existing information.
Three series of measurements were performed on oriented cores of several Yucca Mountain tuffs to determine the importance of mechanical anisotropy in the intact rock. Outcrop and drillhole samples were tested for acoustic velocities, linear compressibilities, and strengths in different orientations. The present data sets are preliminary, but suggest the tuffs are transversely anisotropic for these mechanical properties. The planar fabric that produces the anisotropy is believed to be predominantly the result of the preferred orientation of shards and pumice fragments. The potential of significant anisotropy has direct relevance to the formulation of constitutive formulation and the analyses of an underground opening within Yucca Mountain.
Sandia National Laboratories, as a participant in the Yucca Mountain Project, administered by the Nevada Operations Office of the US Department of Energy, is in the process of evaluating a proposed site for geologic disposal of high-level nuclear wastes in the volcanic tuffs at Yucca Mountain, Nevada. In a repository, loads will be imposed on the rock mass as a result of excavation of the openings and heating of the rock by the nuclear waste. In an attempt to gain a better understanding of the thermal, mechanical, and thermomechanical response of fractured tuff, a series of experiments have been performed, and measurements have been taken in the welded and nonwelded tuffs at the G-Tunnel underground test facility at Rainier Mesa, Nevada. Comparisons between measured and calculated data of the G-Tunnel High-Pressure Flatjack Development Experiment are presented in this investigation. Calculated results were obtained from two dimensional finite element analysis using a recently developed compliant-joint rock-mass model. The purpose of this work was to assess the predictive capability of the model based on limited material property data for the G-Tunnel welded tuff. The results of this evaluation are discussed.
We report the first experiments evaluating the beam generation by the new 4-MV RLA injector. Beams of 15 to 27 kA current were produced and successfully transported up to the first post-accelerating cavity (ET-2), 1.3 m downstream. The beam radius was measured with an x-ray pin-hole camera and found to be equal to 5 mm. We selected an apertured ion-focused foilless diode among the various available diode options. It is the simplest and easiest to operate and can be adjusted to provide variable beam impedance loads. Experimental results will be presented and compared with numerical simulations.
Two controllers are developed to provide attitude control of a spinning rocket that has a thrust vectoring capability. The first controller has a single-input/single-output design that ignores the gyroscopic coupling between the control channels. The second controller has a multi-input/multi-output structure that is specifically intended to account for the gyroscopic coupling effects. A performance comparison between the two approached is conducted for a range of roll rates. Each controller is tested for the ability to track step commands, and for the amount of coupling impurity. Both controllers are developed via a linear-quadratic-regulator synthesis procedure, which is motivated by the multi-input/multi-output nature of second controller. Time responses and a singular value analysis are used to evaluate controller performance. This paper describes the development and comparison of two controllers that are designed to provide attitude control of a spinning rocket that is equipped with thrust vector control. 12 refs., 13 figs., 2 tabs.
The theoretical basis for the relationship between moisture content and light transmission (FFM) is developed, and shown to correspond well to the observed behavior. A calibration procedure for FFM based on the relationship between moisture content and matric potential is presented and tested. Means of expanding the range of sensitivity of the FFM are discussed.
Vawter, G.A.; Myers, D.R.; Brennan, T.M.; Hammons, B.E.
We report dramatic improvements to the implanted-planar buried-heterostructure graded-index separate confinement heterostructure (IPBH-GRINSCH) laser in (AlGa)As/GaAs which produces low threshold current, continuous-wave operation. Our process features significantly reduced fabrication complexity of high quality, index-guided laser diodes compared to regrowth techniques and, in contrast to diffusion-induced disordering, allows creation of self-aligned, buried, blocking junctions by ion implantation. The improved single-stripe IPBH-GRINSCH lasers exhibit 39 mA threshold current, cw operation.
Shock and unloading experiments on quartz and silicate rocks indicate that the release adiabats lie below the Hugoniot. The hysteresis and energy dissipation inherent in this situation have important wave propagation implications. On loading, there is a pressure-induced transition to the stishovite phase which does not occur under conditions of thermodynamic equilibrium, in that the Hugoniot passes through a metastable mixed-phase region for several tens of GPa. One interpretation of the unloading data is that the transition is not reversible, and the phase mixture remains frozen on unloading. However, material strength may also play a role. A complete thermodynamically consistent equation of state which includes phase transitions and strength effects has been developed and used to examine shock and release data on quartz and silicate rocks in order to quantify the kinetics of the reverse transition and to separate the hysteretic effects due to reverse phase transition kinetics from those due to material strength. The model allows quantitative determination of the effect of reverse transition kinetics on ground shock propagation in silicate materials.
On-line chemical monitoring systems can help ensure safe, environmentally sound operation of industrial processes using hazardous chemicals. Using polymer-coated surface acoustic wave (SAW) sensors, we have demonstrated monitors that are capable of detecting dilute concentrations of volatile organic species. Using changes in both wave velocity and wave attenuation, the identity and concentration of an isolated chemical species can be determined. A polysiloxane coating has been found to provide unique properties for monitoring chlorinated hydrocarbons (CHCs) such as trichloroethylene: good discrimination of CHCs from most other organic species, rapid and reversible sensor response, and low detection limits. Using this technology, a portable acoustic wave sensor (PAWS) system has been constructed.
Quantitative analysis routines based on the Bence-Albee, the ZAF, and the {Phi}({rho}Z) techniques are available for the TASK8 microprobe operating system. All of the routines are able to be run from within TASK8 or as stand alone programs. For quick analyses, energy dispersive x-ray data can be collected and processed by running the Tracor standardless quantitative (SQ) routine from within TASK8. For normal analyses, data are collected via the wavelength spectrometers. The procedures and routines described in this document permit the interactive collection and processing of data via joystick control or the automatic collection and processing of data from up to seven line traces or an essentially unlimited number of preselected points. 7 refs., 5 figs., 1 tab.
Sandia National Laboratories operates the Primary Standards Laboratory (PSL) for the Department of Energy, Albuquerque Operations Office (DOE/AL). This report summarizes metrology activities that received emphasis in the first half of 1990 and provides information pertinent to the operation of the DOE/AL system-wide Standards and Calibration Program.
Sandia National Laboratories, Albuquerque, has been designated as Lead Center for the Exploratory Battery Technology Development and Testing Project, which is sponsored by the US Department of Energy's Office of Energy Storage and Distribution. In this capacity, Sandia is responsible for the engineering development of advanced rechargeable batteries for both mobile and stationary energy storage applications. This report details the technical achievements realized in pursuit of the Lead Center's goals during calendar year 1989. 4 refs., 84 figs., 18 tabs.
This report describes some field tests of the CUBIC CR-100 distance measuring equipment. The distance measurements depend on the refractivity of the atmospheric. The CR-100 uses 320 for the refractivity. For the Albuquerque area on a clear spring day, 220 is a more realistic value for refractivity. This difference of 100 between the actual and assumed refractivities causes the range error to accumulate at the rate of 1 meter per 10,000 meters of range. For example, a difference of 100 in refractivity forces the measured range to contain an error of 5 meters for a 50,000 meter baseline. 12 figs.
The Explosive Components Facility (ECF) is to be a new major facility in the Sandia National Laboratories (SNL) Weapons Program. The ECF is a self-contained, secure site on SNL property and is surrounded by Kirtland Air Force Base which is located 6-1/2 miles east of downtown Albuquerque, New Mexico. The ECF will be dedicated to research, development, and testing of detonators, neutron generators, batteries, explosives, and other weapon components. It will have capabilities for conducting explosive test fires, gas gun testing, physical analyses, chemical analyses, electrical testing and ancillary explosive storage in magazines. The ECF complex is composed of a building covering an area of approximately 91,000 square feet, six exterior explosive service magazines and a remote test cell. Approximately 50% of the building space will be devoted to highly specialized laboratory and test areas, the other 50% of the building is considered nonhazardous. Critical to the laboratory and test areas are the blast-structural design consideration and operational considerations, particularly those concerning personnel access control, safety and environmental protection. This area will be decoupled from the rest of the building to the extent that routine tests will not be heard or felt in the administrative area of the building. While the ECF is designed in accordance with the DOE Explosives Safety Manual to mitigate any off-site blast effects, potential injuries or death to the ECF staff may result from an accidental detonation of explosive material within the facility. Therefore, reducing the risk of exposing operation personnel to hazardous and energetic material is paramount in the design of the ECF.
This report describes the Phase 1 drilling operations for the Magma Energy Exploratory Well near Mammoth Lakes, California. An important part of the Department of Energy's Magma Energy Program, this well is designed to reach an ultimate depth of 20,000 feet or a bottomhole temperature of 500{degree}C, whichever comes first. There will be four drilling phases, at least a year apart, with scientific investigations in the borehole between the drilling intervals. Phase 1 of this project resulted in a 20 inch cased hole to 2558 feet, with 185 feet of coring beyond that. This document comprises a narrative of the daily activities, copies of the daily mud and lithologic reports, time breakdowns of rig activities, inventories of lost circulation materials, temperature logs of the cored hole, and a strip chart mud log. 2 figs.
The validity of scale model impact evaluation of the SST Transportation System is acceptable based on Dimensional Analysis (Buckingham Pi Theorem) and the work of numerous programs that have evaluated the agreement among dimensional analysis, several different reduced-size models and full-scale impact test data. Excellent accuracy has been demonstrated between scale models and full-scale impact data when collected in conformance with the Buckingham Pi Theorem. 20 refs., 4 figs.
A five-step procedure was used in the 1990 performance simulations to construct probability distributions of the uncertain variables appearing in the mathematical models used to simulate the Waste Isolation Pilot Plant's (WIPP's) performance. This procedure provides a consistent approach to the construction of probability distributions in cases where empirical data concerning a variable are sparse or absent and minimizes the amount of spurious information that is often introduced into a distribution by assumptions of nonspecialist. The procedure gives first priority to the professional judgment of subject-matter experts and emphasizes the use of site-specific empirical data for the construction of the probability distributions when such data are available. In the absence of sufficient empirical data, the procedure employs the Maximum Entropy Formalism and the subject-matter experts' subjective estimates of the parameters of the distribution to construct a distribution that can be used in a performance simulation. 23 refs., 4 figs., 1 tab.
This report documents the data available as of August 1990 and used by the Performance Assessment Division of Sandia National Laboratories in its December 1990 preliminary performance assessment of the Waste Isolation Pilot Plant (WIPP). Parameter values are presented in table form for the geologic subsystem, engineered barriers, borehole flow properties, climate variability, and intrusion characteristics. Sources for the data and a brief discussion of each parameter are provided. 101 refs., 72 figs., 21 tabs.
A theoretical model was developed for the minimum charge to trigger a gaseous detonation in spherical geometry as a generalization of the Zeldovich model. Careful comparisons were made between the theoretical predictions and experimental data on the minimum charge to trigger detonations in propane-air mixtures. The predictions are an order of magnitude too high, and there is no apparent resolution to the discrepancy. A dynamic model, which takes into account the experimentally observed oscillations in the detonation zone, may be necessary for reliable predictions. 27 refs., 9 figs.