A Seismic Signal Modeling software package has been implemented for the RSTN and the NORESS/ARCESS data. The key features of the software are: (1) It removes over a limited band the gain and phase effects that were introduced by the seismometer and its associated filters. This removal was accomplished by using Finite Impulse Response (FIR) filter techniques to produce a resulting signal in terms of either ground-motion velocity or displacement. (2) It combines two separate bands of data, which are sampled at different rates, into a single broadband signal. (3) It produces a time-domain plot of the signals. (4) It produces a spectral analysis of the signals, including signal-to-noise ratio and comparison of the signals. 5 refs., 22 figs., 3 tabs.
A set of 6-ft-diameter ribbon parachutes (geometric porosities of 7%, 15%, and 30%) was tested in various subsonic wind tunnels covering a range of geometric blockages from 2% to 35%. Drag, base pressure, and inflated geometry were measured under full-open, steady-flow conditions. The result drag areas and pressure coefficients were correlated with the bluff-body blockage parameter (i.e., drag area divided by tunnel cross-sectional area) according to the blockage theory of Maskell. The data show that the Maskell theory provides a simple, accurate correction for the effective increase in dynamic pressure caused by wall constraint for both single parachutes and clusters. For single parachutes, the empirically derived blockage factor K{sub M} has the value of 1.85, independent of canopy porosity. Derived values of K{sub M} for two- and three-parachute clusters are 1.35 and 1.59, respectively. Based on the photometric data, there was no deformation of the inflated shape of the single parachutes up to a geometric blockage of 22%. In the case of the three-parachute cluster, decreases in both the inflated diameter and the spacing among member parachutes were observed at a geometric blockage of 35%. 11 refs., 9 figs., 3 tabs.
Waypoint guidance is a technique used to steer an autonomous vehicle along a desired course. Waypoints are designated at intervals along that course. The guidance algorithms issue steering commands that, if followed, result in the vehicle's traveling from waypoint to waypoint. Thus, the vehicle remains on or very close to the desired trajectory. Waypoints can be specified by latitude, longitude, and altitude in geographic coordinates. The vehicle's current location can be described similarly. This is enough information to determine the direction of travel that would take the vehicle to the waypoint. The shortest route from one point on a spherical surface to another on the same surface is a great circle. A great circle lies in a plane that contains the center of the sphere. The plane also is normal to the surface of the sphere along the great circle. The earth actually is distorted slightly from spherical; it is ellipsoidal. An ellipsoidal earth model will be used in this report. Features of the great circle will be applied to effect good approximations of shortest routes to waypoints. Therefore, only the endpoints of long, straight course segments need be specified. 5 figs.
Drillstem tests, slug tests, a small-scale pumping test, and a large-scale pumping test of the Culebra Dolomite Member of the Rustler Formation were performed in 1988 at the H-11 hydropad at the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico. The drillstem, slug, and small-scale pumping tests were conducted in well H-11b4 to evaluate well and aquifer properties in preparation for a tracer test. The large-scale pumping test, known as the H-11 multipad test, was performed by pumping well H-11b1 in the southern part of the WIPP site at a rate of six gpm for 63 days and monitoring drawdown and recovery responses in three other wells on the H-11 hydropad and at 11 observation wells within a three-mile radius. Responses were observed in 10 of these distant wells. The H-11 multipad pumping test complemented the H-3 and WIPP-13 multipad pumping tests conducted in the central and northern portions of the WIPP site in late 1985 and early 1987, respectively. 67 refs., 124 figs., 31 tabs.
The formation of pristine silica fiber sections in an ultra high vacuum environment requires the critical control of production parameters. Glass temperature and fiber draw force must be precisely controlled to produce favorable results. Process control is achieved by automating the operation of a high power CO{sub 2} laser and the acquisition of data with a dedicated microprocessor. This combination, with the integration of ocular control through the application of digital image processing techniques, has subsequently led to a consistent and reproducible means of forming high quality pristine glass fiber test sections on the order of 25 {mu}m to 50{mu}m in diameter. Fibers formed in this manner are tested to failure (in situ) by applying loads at various rates in controlled environments. This report presents the techniques and devices used to develop this automated fabrication and testing system. 2 refs., 5 figs.
The phase gradient algorithm represents a powerful new signal processing technique with applications to aperture synthesis imaging. These include, for example, synthetic aperture radar phase correction and stellar image reconstruction. The algorithm combines redundant information present in the data to arrive at an estimate of the phase derivative. In this report, we show that the estimator is in fact a linear, minimum variance estimator of the phase derivative. 7 refs.
The quasi-static failure criteria, elastic constants, and p-wave velocities have been determined for a granite and a sandstone in which blasting experiments are being carried out by the Advanced Technology Division (6258). In addition, the dynamic strength of the granite was measured using a Kolsky bar. Both rocks show a linear increase in strength with increasing confining pressure. The dynamic strength of the granite is as much as 330% greater than the quasi-static value. The strength of the granite was also dependent on the angle between the foliation and the loading direction. There was a 20% difference in the p-wave velocity between that measured parallel to and perpendicular to the bedding in the sandstone. 4 refs., 4 figs., 5 tabs.
Blow-by is a common occurrence in two-stage light gas guns. Although the blow-by is often inconsequential, it can sometimes present a serious problem. Various projectile designs have been tried to prevent blow-by, and a successful design is described. Computer calculations which clarify the dynamic performance of the design are presented, along with a parameter variation study to indicate the sensitivity of the design to certain geometric parameters. 6 refs., 12 figs., 1 tab.
The LIFE2 computer code is a fatigue/fracture analysis code specifically designed for the analysis of wind turbine components. It is a PC-compatible Fortran code that is written in a top-down modular format. In this numerical formulation, an S-n'' fatigue analysis is used to describe the initiation, growth and coalescence of micro-cracks into macro-cracks. A linear, da/dn'' fracture analysis is used to describe the growth of a macro-crack. This paper presents the numerical formulations used to implement these analyses. 16 refs., 2 tabs.
LIFE2 is a PC-compatible computer code that analyzes the service lifetime of a WECS component. The LIFE2 code is written in Fortran and has the option of using either a fatigue analysis or a linear fracture mechanics analysis. This document contains information on what the code expects as input and what can be expected as output from the code. Also included are two example problems. 11 refs., 9 figs., 1 tab.
Thermal testing of space payloads at Sandia National Laboratories is conducted in a large cylindrical (7.0 feet in diameter) vacuum chamber with temperature controlled walls. The payload is generally attached to a baseplate with independent temperature controls. To establish well-defined boundary conditions during the tests, uniform wall temperatures are desired in the test chamber. Thermal-vacuum tests were conducted on this space simulation chamber to determine if temperature gradients existed on the chamber shroud and end-bells. Recorded temperature measurements indicated large temperature gradients on the chamber shroud and end-bells. Furthermore, it was difficult to manually control the flow of liquid to the end-bells in order to achieve equal end-bell temperatures. However, results from these tests were used in a computer program developed to predict locations on the shroud and end-balls where a thermocouple would measure the best area-weighted average temperature. These measurements provide necessary boundary temperatures that can be used in a thermal model of a satellite payload. Results were obtained for different shroud and baseplate temperature settings. 8 figs., 5 tabs.
This report summarizes the progress of the Borehole Directional Radar (BDR) System, which is a high-power, high-resolution tool that is being developed to locate lithologic layers or fractures away from a wellbore. The key to the tool's potential is its ability to accurately measure distance and direction of a lithologic discontinuity underground. The results of two field tests in 1988 are presented. The report also discusses the deficiencies of the current system, and a proposed upgrade. Finally, possible other applications of the BDR System are outlined, including (1) locating gas and oil reservoirs below a salt dome, (2) determining the integrity of underground structures (e.g., Strategic Petroleum Reserve, Nuclear Waste Repository Site), and (3) verifying underground nuclear tests. 25 refs., 14 figs.
A computer code is described which is designed to determine the fraction of time during which a given ground location is observable from one or more members of a satellite constellation in earth orbit. Ground visibility parameters are determined from the orientation and strength of an appropriate ionized cylinder (used to simulate a beam experiment) at the selected location. Satellite orbits are computed in a simplified two-body approximation computation. A variety of printed and graphical outputs is provided. 9 refs., 50 figs., 2 tabs.
An algorithm and a computer program are described for use in determining the geographic locations common between the orbit paths of two satellites or between different portions of a single satellite's orbital path. The method selected uses semi-inertial geometric constructions to determine the crossing locations. 6 refs.
The uniaxial compressive strength of air-dry and water-saturated ashfall tuff from the Nevada Test Site was measured as a function of strain rate from 10{sup {minus}6} to 10{sup 3} s{sup {minus}1}. Two different testing devices were used to achieve this wide range in rate, an electro-hydraulic, servo-controlled load frame, and a Kolsky bar. Critical strain rates of 82 s{sup {minus}1} and 22{sup {minus}1} were found for dry and saturated tuffs, respectively. Below the critical rate the strength is a weak function of strain rate and above the critical rate strength varies as the cube root of strain rate. The strengths of the dry and saturated tuff are the same above the critical rate. At slower rates, the saturated tuff is weaker at all rates and shows a slightly stronger strain-rate sensitivity. 26 refs., 5 figs.
A knowledge based computer program that assists programmers of Numerically Controlled (NC) machine tools is described. The program uses part features identified by the NC programmer at a CAD/CAM graphics display and a set of manufacturing rules to select machining parameters and produce NC part programs. An expert system determines the correct NC sequence and the machining parameters. Both milled and point-to-point features are programmed by the Milling Assistant. Examples are included to illustrate the problem domain. Extensions to the Milling Assistant are described. 11 refs.
Various models of steam explosion triggering and propagation are reviewed. An analogy is drawn between steam explosions and chemical combustion, stressing that a continuum of steam explosion intensities can exist, ranging from very weak deflagration-like phenomena to full-scale detonation-like explosions. Evidence is presented to support several hypotheses: (1) that most, if not all, reported steam explosions were not strong steady thermal detonations; (2) that unsteady, oscillatory and partial-reaction steam explosions may exist for a wide range of fragmentation times; (3) that steam explosions may have large reaction zones (or interaction regions) of the order of several meters; (4) that fragmentation times of the order of 40--200 /mu/s may be fast enough to sustain strong thermal detonations; (5) that explosion strength can increase dramatically with trigger strength; and (6) that the product of pressure and impulse may be good measure of trigger strength. New experimental data and calculations are presented to support some of these hypotheses. 84 refs., 19 figs., 1 tab.
This report presents a evaluation of ten video compression systems currently available on the market. The products are presented in a structured format for easy comparison. The features used for comparison purposes include applications, bit rates, processing delays, resolutions, color capabilities, physical size and weight, maintainability, price, and additional features. Further, unique attractions and characteristics, as well as limitations and problems, are discussed.
We at Sandia first became involved with developing energy technology when the nation initiated its push toward energy independence in the early 1970s. That involvement continues to be strong. In shaping Sandia's energy programs for the 1990s, we will build on our track record from the 70s and 80s, a record outlined in this publication. It contains reprints of three issues of Sandia's Lab News that were devoted to our non-nuclear energy programs. Together, they summarize the history, current activities, and future of Sandia's diverse energy concerns; hence my desire to see them in one volume. Written in the fall of 1988, the articles cover Sandia's extremely broad range of energy technologies -- coal, oil and gas, geothermal, solar thermal, photovoltaics, wind, rechargeable batteries, and combustion.
Thermal energy contained in magmatic systems represents a huge potential resource. In the US, useful energy contained in molten and partially-molten magma within the upper 10 km of the crust has been estimated at 50,000 to 500,000 Quads. The objective of the Magma Energy Extraction Program is to determine engineering feasibility of locating, accessing and utilizing magma as a viable energy resource. Engineering feasibility will depend on size and depth of the resource; extraction rates; and material life times. 11 refs., 29 figs., 1 tab.
The diffusion of unreactive solutes through the Culebra Dolomite was studied experimentally and theoretically. The measured diffusive flux is less than that predicted from independent knowledge of the porosity and reasonable estimates of tortuosity. This low measured flux led to a review of the relationship between solute diffusion and pore geometry in rocks and sediments. Solute transport in hypothetical pore networks, where the effect of pore geometry on the solute flux is directly calculable, is examined. A conventional interpretation of pore tortuosity, as a normalized length of diffusion through a pore, loses meaning for cases where pores intersect in networks. Some important variables affecting the tortuosity are: (1) the distribution of pore sizes (2) the distribution of pore lengths, (3) the number of pores which intersect at a node, and (4) the pore shape between nodes. Furthermore, in porous materials with a preferential distribution of pore sizes and orientation, tortuosity is a tensor. For the Culebra Dolomite, the wide range of pore sizes causes the diffusive flux to vary considerably from that predicted from conventional theory. These results indicate that diffusive fluxes from fractures into rock pores may be smaller than previously thought. 35 refs., 10 figs., 2 tabs.
We describe the relationship between constant resistive load, constant current, and constant voltage discharges of electrochemical cells using the concept of the polarization curve. This concept is demonstrated under constraints for a prismatic Li/SOCl{sub 2} laboratory cell. We show that each of these discharges yields the same information about the electrochemical couple which drives the cell. 8 figs.
LEXER is a useful tool for lexical analysis. It is designed to give an application programmer the ability to write code that will quickly parse commands to an interactive program. It is also useful in parsing character data stored in a file. This is done by lexically analyzing the input character string and placing its components and related information into arrays stored in common blocks. The code is written in FORTRAN which conforms to the ANSI Standard FORTRAN 77 in all but a few carefully documented areas. 2 refs.
Teleoperation of land vehicles was studied to investigate the effects of both spatial and temporal video resolution on the ability of the operator to effectively control the vehicle. Teleoperation extends part of a human operator's presence into remote or hazardous areas, and the predominant form of sensory feedback is that of vision. The quality of the transmitted video information has a significant effect on the operator's confidence and ability to effectively control the vehicle. Experiments were constructed to allow subjective evaluation of the lower limits of video quality necessary for degraded, yet effective, Teleoperation. Subjects were asked to teleoperate a remote vehicle under varying conditions to degraded spatial and temporal resolution, and their comments were recorded along with the video driving scenes during teleoperation. Subjective assessments and teleoperation test data suggest the possibility of reducing the required video bandwidth for teleoperation by a factor of 28:1 over normal video standards. 9 refs., 18 figs., 9 tabs.
This document is a collection of abstracts of papers prepared as part of the Sandia programs in the GeoEnergy Technology Department and other closely related research. Areas of technology represented are resource access (drilling, blasting), resource extraction (enhanced recovery) and geodiagnostics. More basic work in the Geosciences is in a separate chapter. Industry programs and Technology Transfer constitute a final section. That section also includes our geotechnical support to DOE on the Strategic Petroleum Reserve in which we work closely with the SPR site contractor. 65 refs.