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Corrective Action Investigation Plan: Roller Coaster Lagoons and North Disposal Trench, Tonopah Test Range, Revision 1
No full text1.1 Purpose The purpose of this investigation is to collect data to confirm the presence or absence of contamination, evaluate the potential for contaminant migration, and select appropriate closure methods for these sites. The potential closure methods for these sites involve either clean closure, closure in place, or no further action. 1.2 Scope The scope of this investigation includes collecting surface and subsurface soil samples at the Roller Coaster Lagoons; and collecting surface soil samples at the North Disposal Trench and the small spill area associated with the Voluntary Cotiective Action (VCA) that was conducted in 1995
Theoretical Analysis of the Sensitivity and Speed Improvement of ISIS over a Comparable Traditional Hyperspectral Imager
No full textThe analysis presented herein predicts that, under signal-independent noise limited conditions, an Information-efficient Spectral Imaging Sensor (ISIS) style hyperspectral imaging system design can obtain significant signal-to-noise ratio (SNR) and speed increase relative to a comparable traditional hyperspectral imaging (HSI) instrument. Factors of forty are reasonable for a single vector, and factors of eight are reasonable for a five-vector measurement. These advantages can be traded with other system parameters in an overall sensor system design to allow a variety of applications to be done that otherwise would be impossible within the constraints of the traditional HSI style design
Dynamic equation of state and strength properties of unreacted PBXW-128 explosive
No full textShock equation of state and strength data have been obtained on the explosive PBXW-128 over the pressure range O-3 GPa using gun impact techniques and velocity interferometry diagnostics. Nonlinear shock-velocity-versus-particle velocity behavior is observed. Possible mechanisms are discussed and a Hug.oniot equation of slate model for the data is provided
Multispectral UV Fluorescence Detection of a Dilute Constituent in an Optically Dense Matrix
No full textMultispectral UV fluorescence measurements were made of an optically dense medium (fetal bovine serum, FBS) spiked with sodium salicylate at concentrate ions from 0.2 to 500 pg/ml . Analysis of the spectra show that, depending on experimental conditions, reasonably good estimates of concentration can be obtained across the entire range of concentrate ions. Experimental conditions required for recovering these estimates are demonstrated
Differences Between Distributed and Parallel Systems
No full textDistributed systems have been studied for twenty years and are now coming into wider use as fast networks and powerful workstations become more readily available. In many respects a massively parallel computer resembles a network of workstations and it is tempting to port a distributed operating system to such a machine. However, there are significant differences between these two environments and a parallel operating system is needed to get the best performance out of a massively parallel system. This report characterizes the differences between distributed systems, networks of workstations, and massively parallel systems and analyzes the impact of these differences on operating system design. In the second part of the report, we introduce Puma, an operating system specifically developed for massively parallel systems. We describe Puma portals, the basic building blocks for message passing paradigms implemented on top of Puma, and show how the differences observed in the first part of the report have influenced the design and implementation of Puma
Challenges of Extracting and Purifying Fission-Produced Molybdenum-99
No full textSandia National Laboratories (SNL) has produced limited quantities of fission-produced molybdenum-99 ~%lo) within industry purity specifications using the Cintichem production process. The chemical extraction and purification of `%lo was petiormed using the Hot Cell Facility (HCF) located at Technical Area-V. To thoroughly understand the production process, two series of tests were designed, the first was a series of cold tests using 20 g samples of depleted or low irradiated uranium dioxide powder and the second series was conducted using irradiated targets. In addition, radiation effects tests were petiormed at the SNL Gamma Irradiation Facility (GIF) on chemicals and hardware used in the processing to evaluate the degradation due to the high radiation field expected during the chemical separation. Unique production hardware, fixtures and tools were developed for remote processing of irradiated targets at the HCF
Inductively Coupled Plasma Etching of III-V Antimonides in BCl(3)/Ar and Cl(2)/Ar
No full textInductively coupled plasma (ICP) etching characteristics of GaSb and AIGaAsSb have been investigated in BC13/Ar and Clz/Ar plasmas. The etch rates and selectivity between GaSb and AIGaAsSb are reported as functions of plasma chemistry, ICP power, RF self-bias, and chamber pressure. It is found that physical sputtering resorption of the etch products plays a dominant role in BC13/Ar ICP etching, while in Clz/Ar plasma, the chemical reaction dominates the etching. GaSb etch rates exceeding 2 ~rnhnin are achieved in Clz/Ar plasmas with smooth surfaces and anisotropic profiles. In BC13/Ar plasmas, etch rates of 5100 Mmin and 4200 Mmin are obtained for GaSb and AIGaAsSb, respectively. The surfaces of both GaSb and AIGaAsSb etched in BC13/Ar plasmas remain smooth and stoichiometric over the entire range of plasma conditions investigated. This result is attributed to effective removal of etch products by physical sputtering. For a wide range of plasma conditions, the selectivity between GaSb and AIGaAsSb is close to unity, which is desirable for fabricating etched mirrors and gratings for Sb-based mid-IR laser diodes
A Methodology to Validate 3-D Arbitrary Lagrangian Eulerian Codes with Applications to Alegra
No full textIn this study we provided an experimental test bed for validating features of the Arbitrary Lagrangian Eulerian Grid for Research Applications (ALEGRA) code over a broad range of strain rates with overlapping diagnostics that encompass the multiple responses. A unique feature of the ALEGRA code is that it allows simultaneous computational treatment, within one code, of a wide range of strain-rates varying from hydrodynamic to structural conditions. This range encompasses strain rates characteristic of shock-wave propagation (107/s) and those characteristics of structural response (102/s). Most previous code validation experimental &udies, however, have been restricted to simulating or investigating a single strain-rate regime. What is new and different in this investigation is that we have performed well-controlled and well-instrumented experiments, which capture features relevant to both hydrodynamic and structural response in a single experiment. Aluminum was chosen for use in this study because it is a well-characterized material. The current experiments span strain rate regimes of over 107/s to less than 102/s in a single experiment. The input conditions were extremely well defined. Velocity interferometers were used to record the high' strain-rate response, while low strain rate data were collected using strain gauges. Although the current tests were conducted at a nominal velocity of - 1.5 km/s, it is the test methodology that is being emphasized herein. Results of a three-dimensional experiment are also presented
Development of a GaAs-Based Monolithic Surface Acoustic Wave Integrated Chemical Microsensor
No full textAn oscillator technology using surface acoustic wave delay lines integrated with GaAs MESFET electronics has been developed for GaAs-based integrated microsensor applications. Oscillators with frequencies of 470, 350, and 200 MHz have been designed and fabricated. These oscillators are also promising for other rf applications
Statistical Considerations in Designing Tests of Mine Detection Systems: II - Measures Related to the False Alarm Rate
No full textThe rate at which a mine detection system falsely identifies man-made or natural clutter objects as mines is referred to as the system's false alarm rate (FAR). Generally expressed as a rate per unit area or time, the FAR is one of the primary metrics used to gauge system performance. In this report, an overview is given of statistical methods appropriate for the analysis of data relating to FAR. Techniques are presented for determining a suitable size for the clutter collection area, for summarizing the performance of a single sensor, and for comparing different sensors. For readers requiring more thorough coverage of the topics discussed, references to the statistical literature are provided. A companion report addresses statistical issues related to the estimation of mine detection probabilities