Applications of Multivariate Statistical Analysis (MSA) in Microanalysis (open access)

Applications of Multivariate Statistical Analysis (MSA) in Microanalysis

Recent improvements in computer hardware and software for the acquisition, storage and analysis of series of spectra and images allow for a change in strategy for quantitative microanalysis. For example, in the area of X-ray microanalysis, whereas compositional analysis and elemental distributions have been traditionally performed using point microanalysis and simple intensity mapping from a ROI, respectively, the two tasks are now routinely performed simultaneously through X-ray spectrum-imaging, where full spectra are acquired from pixels in a two-dimensional array of points on the specimen. Commercially available software now allows for the acquisition and storage of such spectrum-images, perhaps comprising as much as 100 MBytes of data or more. A variety of post-acquisition processing tools are provided by the developer to allow the extraction of both X-ray intensity maps, with or without rudimentary background subtraction, or full spectra from pixels of interest. In order to maximize the extraction of information from these large data sets, a number of linear and nonlinear methods are currently being explored that identify statistically significant variations among the series of spectra without a priori assumptions about the content of the data set. Among these methods, linear multivariate statistical analysis (MSA) has a number of significant advantages, …
Date: February 16, 1999
Creator: Anderson, I. M.
Object Type: Article
System: The UNT Digital Library
Aquatic Macroinvertebrate Surveys in Upper Three Runs Creek and Pen Branch (Task Order 181) (open access)

Aquatic Macroinvertebrate Surveys in Upper Three Runs Creek and Pen Branch (Task Order 181)

This report talks about Aquatic Macroinvertebrate Surveys in Upper Three Runs Creek and Pen Branch (Task Order 181).
Date: February 16, 1999
Creator: Paller, M.
Object Type: Report
System: The UNT Digital Library
Correlation of Creep Behavior of Domal Salts (open access)

Correlation of Creep Behavior of Domal Salts

The experimentally determined creep responses of a number of domal salts have been reported in, the literature. Some of these creep results were obtained using standard (conventional) creep tests. However, more typically, the creep data have come from multistage creep tests, where the number of specimens available for testing was small. An incremental test uses abrupt changes in stress and temperature to produce several time increments (stages) of different creep conditions. Clearly, the ability to analyze these limited data and to correlate them with each other could be of considerable potential value in establishing the mechanical characteristics of salt domes, both generally and specifically. In any analysis, it is necessary to have a framework of rules to provide consistency. The basis for the framework is the Multimechanism-Deformation (M-D) constitutive model. This model utilizes considerable general knowledge of material creep deformation to supplement specific knowledge of the material response of salt. Because the creep of salt is controlled by just a few micromechanical mechanisms, regardless of the origin of the salt, certain of the material parameters are values that can be considered universal to salt. Actual data analysis utilizes the methodology developed for the Waste Isolation Pilot Plant (WIPP) program, and …
Date: February 16, 1999
Creator: Munson, Darrell E.
Object Type: Article
System: The UNT Digital Library
Design and performance of the main amplifier system for the National Ignition Facility (open access)

Design and performance of the main amplifier system for the National Ignition Facility

This paper describes the design and performance of flashlamp-pumped, Nd:glass. Brewster-angle slab amplifiers intended to be deployed in the National Ignition Facility (NIF). To verify performance, we tested a full-size, three-slab-long, NIF prototype amplifier, which we believe to be the largest flashlamp-pumped Nd:glass amplifier ever assembled. Like the NIF amplifier design, this prototype amplifier had eight 40-cm-square apertures combined in a four-aperture-high by two-aperture-wide matrix. Specially-shaped reflectors, anti-reflective coatings on the blastshields, and preionized flashlamps were used to increase storage efficiency. Cooling gas was flowed over the flashlamps to remove waste pump heat and to accelerate thermal wavefront recovery. The prototype gain results are consistent with model predictions and provide high confidence in the final engineering design of the NIF amplifiers. Although the dimensions, internal positions, and shapes of the components in the NIF amplifiers will be slightly different from the prototype, these differences are small and should produce only slight differences in amplifier performance
Date: February 16, 1999
Creator: Beullier, J; Erlandson, A; Grebot, E; Guenet, J; Guenet, M; Horvath, J et al.
Object Type: Article
System: The UNT Digital Library
Early deterioration of coarse woody debris. (open access)

Early deterioration of coarse woody debris.

Tainter, F.H., and J.W. McMinn. 1999. Early deterioration of coarse woody debris. In: Proc. Tenth Bien. South. Silv. Res. Conf. Shreveport, LA, February 16-18, 1999. Pp. 232-237 Abstract - Coarse woody debris (CWD) is an important structural component of southern forest ecosystems. CWD loading may be affected by different decomposition rates on sites of varying quality. Bolts of red oak and loblolly pine were placed on plots at each of three (hydric, mesic. and xerlc) sites at the Savannah River Site and sampled over a I6-week period. Major changes were in moisture content and nonstructural carbohydrate content (total carbohydrates, reducing sugars, and starch) of sapwood. Early changes in nonstructural carbohydrate levels following placement of the bolts were likely due to reallocation of these materials by sapwood parenchyma cells. These carbohydrates later formed pools increasingly metabolized by bacteria and invading fungi. Most prevalent fungi in sapwood were Ceratocysfis spp. in pine and Hypoxy/on spp. in oak. Although pine sapwood became blue stained and oak sapwood exhibited yellow soft decay with black zone lines, estimators of decay (specific gravity, sodium hydroxide solubility, and holocellulose content) were unchanged during the 16-week study period. A small effect of site was detected for starch content …
Date: February 16, 1999
Creator: Tainter, Frank, H. & McMinn, James, W.
Object Type: Article
System: The UNT Digital Library
Failure Mode and Effects RHIC Cryogenic Liquid Storage Area (open access)

Failure Mode and Effects RHIC Cryogenic Liquid Storage Area

None
Date: February 16, 1999
Creator: M., Gaffney
Object Type: Report
System: The UNT Digital Library
Final report for the Advanced Natural Gas Vehicle Project (open access)

Final report for the Advanced Natural Gas Vehicle Project

The project objective was to develop the technologies necessary to prototype a dedicated compressed natural gas (CNG) powered, mid-size automobile with operational capabilities comparable to gasoline automobiles. A system approach was used to design and develop the engine, gas storage system and vehicle packaging. The 2.4-liter DOHC engine was optimized for natural gas operation with high-compression pistons, hardened exhaust valves, a methane-specific catalytic converter and multi-point gaseous injection. The chassis was repackaging to increase space for fuel storage with a custom-designed, cast-aluminum, semi-trailing arm rear suspension system, a revised flat trunk sheet-metal floorpan and by equipping the car with run-flat tires. An Integrated Storage system (ISS) was developed using all-composite, small-diameter cylinders encapsulated within a high-strength fiberglass shell with impact-absorbing foam. The prototypes achieved the target goals of a city/highway driving range of 300 miles, ample trunk capacity, gasoline vehicle performance and ultra low exhaust emissions.
Date: February 16, 1999
Creator: Wozniak, John
Object Type: Report
System: The UNT Digital Library
Gravity-destabilized nonwetting phase invasion in macro-heterogeneous porous media: Experimental observations of invasion dynamics and scale analysis (open access)

Gravity-destabilized nonwetting phase invasion in macro-heterogeneous porous media: Experimental observations of invasion dynamics and scale analysis

The authors designed and conducted experiments in a heterogeneous sand pack where gravity-destabilized nonwetting phase invasion (CO{sub 2} and TCE) could be recorded using high resolution light transmission methods. The heterogeneity structure was designed to be reminiscent of fluvial channel lag cut-and-fill architecture and contain a series of capillary barriers. As invasion progressed, nonwetting phase structure developed a series of fingers and pools; behind the growing front they found nonwetting phase saturation to pulsate in certain regions when viscous forces were low. Through a scale analysis, they derive a series of length scales that describe finger diameter, pool height and width, and regions where pulsation occurs within a heterogeneous porous medium. In all cases, they find that the intrinsic pore scale nature of the invasion process and resulting structure must be incorporated into the analysis to explain experimental results. The authors propose a simple macro-scale structural growth model that assembles length scales for sub-structures to delineate nonwetting phase migration from a source into a heterogeneous domain. For such a model applied at the field scale for DNAPL migration, they expect capillary and gravity forces within the complex subsurface lithology to play the primary roles with viscous forces forming a perturbation …
Date: February 16, 1999
Creator: GLASS JR.,ROBERT J.; CONRAD,STEPHEN H. & PEPLINSKI,WILLIAM J.
Object Type: Article
System: The UNT Digital Library
High-Power Reliable Operation of InGaAsP/InP Laser Bars at 1.73 {micro}m (open access)

High-Power Reliable Operation of InGaAsP/InP Laser Bars at 1.73 {micro}m

InGaAsP/InP laser bars with an emission wavelength of 1.73 {micro}m have been fabricated using compressively-strained multiple-quantum-well separate-confinement heterostructures. One-cm-wide, 0.7-fill-factor, diode bars are bonded onto Si microchannel heatsinks. A maximum cw power of 16 W was produced from a one-cm bar. Derated to SW cw, the extrapolated lifetime is 10,000 hours of operation with a 20% degradation in output power. A 10-bar microlensed diode array with a one-square-cm aperture produced 200 W of peak power and was focused onto a Cr:ZnSe slab laser. Over 3 watts of pulsed power and xxmw of average power was generated at a wavelength of 2.5 {micro}m.
Date: February 16, 1999
Creator: Skidmore, J.; Page, R. H.; Freitas, B. L.; Reinhardt, C. E.; Utterback, E. J. & Emanuel, M. A.
Object Type: Article
System: The UNT Digital Library
Microscale Flow Modeling in Geologic Materials (open access)

Microscale Flow Modeling in Geologic Materials

Three-dimensional imaging techniques, numerical methods for simulating flow and transport, and emergent computational architectures are combined to enable fundamental studies of fluid flow at the pore scale. High resolution reconstructions of porous media obtained using laser scanning confocal microscopy reduce sampling artifacts to sub-micron features, and simultaneously capture multiple grain length scales. However, the volumetric image data sets are extremely large, and there are significant computational challenges in utilizing this information effectively. The principal problem lies in the complexity of the geometry and the retention of this structure in numerical analyses. Lattice Boltzmann (LB) methods provide a direct means to simulate transport processes in complex geometric domains due to the unique ability to treat accurately and efficiently the multitude of discrete boundary conditions. LB methods are numerically explicit as formulated, and this characteristic is exploited through a mapping of the numerical domain to distributed computing architectures. These techniques are applied to perform single phase flow simulations in 3D data sets obtained from cores of Berea sandstone using confocal microscopy. Simulations are performed using both a purpose-built distributed processor computer and a massively parallel processer (MPP) platform.
Date: February 16, 1999
Creator: Fredrich, J.T. & O'Connor, R.M.
Object Type: Article
System: The UNT Digital Library
Monsters and babies from the first/IRAS survey (open access)

Monsters and babies from the first/IRAS survey

Radio continuum emission at cm wavelengths is relatively little affected by extinction. When combined with far-infrared (FIR) surveys this provides for a convenient and unbiased method to select (radio-loud) AGN and starbursts deeply embedded in gas and dust-rich galaxies. Such radio-selected FIR samples are useful for detailed investigations of the complex relationships between (radio) galaxy and starburst activity, and to determine whether ULIRGs are powered by hidden quasars (monsters) or young stars (babies). We present the results of a large program to obtain identifications and spectra of radio-sleected, optically faint IRAS/FSC objects using the FIRST/VLA 20 cm survey (Becker, White and Helfand 1995). These objects are all radio-'quiet' in the sense that their radio power/FIR luminosities follow the well-known radio/FIR relationship for star forming galaxies. We compare these results to a previous study by our group of a sample of radio-'loud' IRAS/FSC ULIRGs selected from the Texas 365 MHz survey (Douglas et al. 1996). Many of these objects also show evidence for dominant, A-type stellar populations, as well as high ionization lines usually associated with AGN. These radio-loud ULIRGs have properties intermediate between those of starbursts and quasars, suggesting a possibile evolutionary connection. Deep Keck spectroscopic observations of three ULIRGs …
Date: February 16, 1999
Creator: Van Bruegel, W J M
Object Type: Article
System: The UNT Digital Library
Muon Collider: Muon Generation, Capture and Cooling (open access)

Muon Collider: Muon Generation, Capture and Cooling

A {mu}{sup +} -{mu}{sup -} collider requires a high-intensity proton source for {pi}-production, a high-acceptance {pi}-{mu} decay channel, a {mu}-cooling system, a rapid acceleration system, and a high-luminosity collider ring for the collision of short, intense {mu}{sup +} -{mu}{sup -} bunches. Critical problems exist in developing and compressing high-energy proton bunches for producing {pi}�s, in capturing {pi}�s and their decay {mu}�s, and in cooling {mu}�s into a compressed phase-space at which high luminosity collisions are possible. These problems and some possible solutions are discussed; the current {mu}{sup +} -{mu}{sup -} collider research program is described
Date: February 16, 1999
Creator: Neuffer, David
Object Type: Article
System: The UNT Digital Library
Optical Isolation of Scintillating Tiles Using TiO{subscript 2} Doped Epoxy for the D-Zero ICD in Run II (open access)

Optical Isolation of Scintillating Tiles Using TiO{subscript 2} Doped Epoxy for the D-Zero ICD in Run II

A Run II D0 Inter Cryostat Detector tile array will be composed of 16 identical modules. Each module contains 12 optically isolated scintillating tile elements, each with dimension of 0.1 x 0.1 in {eta} and {phi} in the pseudora-pidity region from 1.1 to 1.4. The 12 tiles in a module are formed by routing grooves in a single piece of scintillator - optical isolation is achieved by fill-ing the grooves with a white re ective epoxy. The procedure for filling these isolation grooves is described here.
Date: February 16, 1999
Creator: Gallas, Elizabeth
Object Type: Report
System: The UNT Digital Library
Photovoltaic Energy Program Contract Summary; Fiscal Year 1998 (open access)

Photovoltaic Energy Program Contract Summary; Fiscal Year 1998

This document provides individual summaries of some 200 photovoltaics research projects performed in house and by subcontractors to Department of Energy national laboratories and field offices, including the National Renewable Energy Laboratory, Sandia National Laboratories, Golden Field Office, Brookhaven National Laboratory, Albuquerque Field Office, and Boston Support Office. The document is divided into the following sections: research and development, technology development, and systems engineering and applications. Three indexes are included: performing organizations by name, performing organizations by state, and performing organizations by technology area.
Date: February 16, 1999
Creator: Surek, T.
Object Type: Report
System: The UNT Digital Library
Recombination Lifetime of InxGa1-xAs Alloys Used in Thermophotovoltaic Converters (open access)

Recombination Lifetime of InxGa1-xAs Alloys Used in Thermophotovoltaic Converters

The family of ternary compounds of composition InxGa1-xAs are of considerable interest for thermophotovoltaic energy converters. The recombination lifetimes of the various compositions are critical to the successful application of these materials as efficient converters. Here we will describe experimental results on the composition. In0.53Ga0.47 that is lattice-matched to InP. We will also describe lifetime results on the compositions In0.68Ga0.32As, with bandgap of 0.60 eV to compositions In0.78Ga0.22As with a bandgap of 0.50 eV. Double heterostructure confinement devices have been made over a range of both n- and p-type doping. These results are preliminary, but the goal is to obtain the radiative and Auger recombination coefficients for the alloys in this composition range.
Date: February 16, 1999
Creator: Ahrenkiel, R. K.; Ellingson, R.; Johnston, S.; Webb, J.; Carapella, J. & Wanlass, M.
Object Type: Article
System: The UNT Digital Library
Record of Technical Change No.1 for ``Corrective Action Investigation Plan for Corrective Action Unit 321: Area 22 Weather Station Fuel Storage, Nevada Test Site, Nevada'' (open access)

Record of Technical Change No.1 for ``Corrective Action Investigation Plan for Corrective Action Unit 321: Area 22 Weather Station Fuel Storage, Nevada Test Site, Nevada''

This Record of Technical Change provides updates to the technical information provided in ''Corrective Action Investigation Plan for Corrective Action Unit 321: Area 22 Weather Station Fuel Storage, Nevada Test Site, Nevada,'' Revision 0. The change specified is in Table 3-1 on page 11. The total lead analyte should specify a Minimum Reporting Limit for soil of 1.0 mg/kg instead of 0.3 mg/kg. The EMAX laboratory cannot meet the 0.3 mg/kg limit.
Date: February 16, 1999
Creator: United States. Department of Energy. Nevada Operations Office.
Object Type: Report
System: The UNT Digital Library
Studies of Nonlinear QED in Collisions of 46.6 Electrons with Intense LaserPulses (open access)

Studies of Nonlinear QED in Collisions of 46.6 Electrons with Intense LaserPulses

We report on measurements of quantum electrodynamic processes in an intense electromagnetic wave, where nonlinear effects (both multiphoton and vacuum polarization) are prominent. Nonlinear Compton scattering and electron-positron pair production have been observed in collisions of 46.6 GeV and 49.1 GeV electrons of the Final Focus Test Beam at SLAC with terawatt pulses of 1053 nm and 527 nm wavelengths from a Nd:glass laser. Peak laser intensities of approximately 0.5 x 10{sup 18} W/cm{sup 2} have been achieved, corresponding to a value of approximately 0.4 for the parameter {eta} = eE{sub rms}/m{omega}{sub 0}c, and to a value of approximately 0.25 for the parameter {Upsilon}{sub e} = E{sub rms}/E{sub crit} = eE{sub rms}{h_bar}/m{sup 2}c{sup 3}, where E{sub rms} is the rms electric field strength of the laser in the electron rest frame. We present data on the scattered electron spectra arising from nonlinear Compton scattering with up to four photons absorbed from the field. A convolved spectrum of the forward high energy photons is also given. The observed positron production rate depends on the fifth power of the laser intensity, as expected for a process where five photons are absorbed from the field. The positrons are interpreted as arising from the …
Date: February 16, 1999
Creator: McDonald, Kirk T.
Object Type: Report
System: The UNT Digital Library
Techniques for enhancing laser ultrasonic nondestructive evaluation (open access)

Techniques for enhancing laser ultrasonic nondestructive evaluation

Ultrasonic nondestructive evaluation is an extremely powerful tool for characterizing materials and detecting defects. A majority of the ultrasonic nondestructive evaluation is performed with piezoelectric transducers that generate and detect high frequency acoustic energy. The liquid needed to couple the high frequency acoustic energy from the piezoelectric transducers restricts the applicability of ultrasonics. For example, traditional ultrasonics cannot evaluate parts at elevated temperatures or components that would be damaged by contact with a fluid. They are developing a technology that remotely generates and detects the ultrasonic pulses with lasers and consequently there is no requirement for liquids. Thus the research in laser-based ultrasound allows them to solve inspection problems with ultrasonics that could not be done before. This technology has wide application in many Lawrence Livermore National Laboratory programs, especially when remote and/or non-contact sensing is necessary.
Date: February 16, 1999
Creator: Candy, J; Chinn, D; Huber, R; Spicer, J & Thomas, G
Object Type: Report
System: The UNT Digital Library
Transporting transuranic waste to the Waste Isolation Pilot Plant: Risk and cost perspectives (open access)

Transporting transuranic waste to the Waste Isolation Pilot Plant: Risk and cost perspectives

The Waste Isolation Pilot Plant (WIPP) is an authorized US Department of Energy (DOE) research and development facility constructed near the city of Carlsbad in southeastern New Mexico. The facility is intended to demonstrate the safe disposal of transuranic (TRU) radioactive waste resulting from US defense activities. Under the WIPP Land Withdrawal Act of 1992 (LWA), federal lands surrounding the WIPP facility were withdrawn from all public use and the title of those lands was transferred to the Secretary of Energy. The DOE's TRU waste is stored, and in some cases is still being generated, at 10 large-quantity and 13 small-quantity sites across the US. After applicable certification requirements have been met, the TRU waste at these sites will be sent to the WIPP to initiate the disposal phase of the facility, which according to current planning is projected to last for approximately 35 years.
Date: February 16, 1999
Creator: Biwer, B. M.; Gilette, J. L.; Poch, L. A. & Suermann, J. F.
Object Type: Article
System: The UNT Digital Library
Transverse Phase Space Reconstruction of the RHIC Beam (open access)

Transverse Phase Space Reconstruction of the RHIC Beam

None
Date: February 16, 1999
Creator: Connolly, R.
Object Type: Report
System: The UNT Digital Library
The Very Large Hadron Collider (open access)

The Very Large Hadron Collider

I present some of the current ideas about a Very Large Hadron Collider [1] which could eventually extend the high energy frontier beyond that of the Large Hadron Collider (LHC) or any other machine seriously conceived at this time.
Date: February 16, 1999
Creator: Albrow, Michael G.
Object Type: Article
System: The UNT Digital Library
Better Methods for Predicting Lifetimes of Seal Materials (open access)

Better Methods for Predicting Lifetimes of Seal Materials

We have been working for many years to develop better methods for predicting the lifetimes of polymer materials. Because of the recent interest in extending the lifetimes of nuclear weapons and the importance of environmental seals (o-rings, gaskets) for protecting weapon interiors against oxygen and water vapor, we have recently turned our attention to seal materials. Perhaps the most important environmental o-ring material is butyl rubber, used in various military applications. Although it is the optimum choice from a water permeability perspective, butyl can be marginal from an aging point-of-view. The purpose of the present work was to derive better methods for predicting seal lifetimes and applying these methods to an important butyl material, Parker compound B6 12-70.
Date: March 16, 1999
Creator: Celina, M.; Gillen, K. T. & Keenan, M. R.
Object Type: Article
System: The UNT Digital Library
CAFE: A Computer Tool for Accurate Simulation of the Regulatory Pool Fire Environment for Type B Packages (open access)

CAFE: A Computer Tool for Accurate Simulation of the Regulatory Pool Fire Environment for Type B Packages

The Container Analysis Fire Environment computer code (CAFE) is intended to provide Type B package designers with an enhanced engulfing fire boundary condition when combined with the PATRAN/P-Thermal commercial code. Historically an engulfing fire boundary condition has been modeled as {sigma}T{sup 4} where {sigma} is the Stefan-Boltzman constant, and T is the fire temperature. The CAFE code includes the necessary chemistry, thermal radiation, and fluid mechanics to model an engulfing fire. Effects included are the local cooling of gases that form a protective boundary layer that reduces the incoming radiant heat flux to values lower than expected from a simple {sigma}T{sup 4} model. In addition, the effect of object shape on mixing that may increase the local fire temperature is included. Both high and low temperature regions that depend upon the local availability of oxygen are also calculated. Thus the competing effects that can both increase and decrease the local values of radiant heat flux are included in a reamer that is not predictable a-priori. The CAFE package consists of a group of computer subroutines that can be linked to workstation-based thermal analysis codes in order to predict package performance during regulatory and other accident fire scenarios.
Date: March 16, 1999
Creator: Gritzo, L. A.; Koski, J. A. & Suo-Anttila, A. J.
Object Type: Article
System: The UNT Digital Library
Corrosion in Non-Hermetic Microelectronic Devices (open access)

Corrosion in Non-Hermetic Microelectronic Devices

Many types of integrated and discrete microelectronic devices exist in the enduring stockpile. In the past, most of these devices have used conventional ceramic hermetic packaging (CHP) technology. Sometime in the future, plastic encapsulated microelectronic (PEM) devices will almost certainly enter the inventory. In the presence of moisture, several of the aluminum-containing metallization features common to both types of packaging become susceptible to atmospheric corrosion (Figure 1). A breach in hermeticity (e.g., due to a crack in the ceramic body or lid seal) could allow moisture and/or contamination to enter the interior of a CHP device. For PEM components, the epoxy encapsulant material is inherently permeable to moisture. A multi-year project is now underway at Sandia to develop the knowledge base and analytical tools needed to quantitatively predict the effect of corrosion on microelectronic performance and reliability. The issue of corrosion-induced failure surfaced twice during the past year because cracks were found in their ceramic bodies of two different CHP devices: the SA371 1/3712 MOSFET and the SA3935 ASIC (acronym for A Simple Integrated Circuit). Because of our inability to perform a model-based prediction at that time, the decision was made to determine the validity of the corrosion concern for …
Date: March 16, 1999
Creator: Braithwaite, J. W. & Sorensen, N. R.
Object Type: Article
System: The UNT Digital Library