States

Effect of Inert Gas Additive Species on Cl(2) High Density Plasma Etching of Compound Semiconductors: Part II. InP, InSb, InGaP and InGaAs (open access)

Effect of Inert Gas Additive Species on Cl(2) High Density Plasma Etching of Compound Semiconductors: Part II. InP, InSb, InGaP and InGaAs

The effects of the additive noble gases He, Ar and Xe on chlorine-based Inductively Coupled Plasma etching of InP, InSb, InGaP and InGaAs were studied as a function of source power, chuck power and discharge composition. The etch rates of all materials with C12/He and C12/Xe are greater than with C12/Ar. Etch rates in excess of 4.8 pndmin for InP and InSb with C12/He or C12/Xe, 0.9 pndmin for InGaP with C12/Xe, and 3.8 prdmin for InGaAs with Clz/Xe were obtained at 750 W ICP power, 250 W rf power, - 1570 C12 and 5 mTorr. All three plasma chemistries produced smooth morphologies for the etched InGaP surfaces, while the etched surface of InP showed rough morphology under all conditions.
Date: December 17, 1998
Creator: Abernathy, C.R.; Cho, H.; Hahn, Y.B.; Hays, D.C.; Jung, K.B.; Pearton, S.J. et al.
Object Type: Article
System: The UNT Digital Library
LBNL perspective on inertial fusion energy (open access)

LBNL perspective on inertial fusion energy

None
Date: December 17, 1995
Creator: Bangerter, Roger O.
Object Type: Report
System: The UNT Digital Library
Cesium removal and kinetics equilibrium: Precipitation kinetics (open access)

Cesium removal and kinetics equilibrium: Precipitation kinetics

This task consisted of both non-radioactive and radioactive (tracer) tests examining the influence of potentially significant variables on cesium tetraphenylborate precipitation kinetics. The work investigated the time required to reach cesium decontamination and the conditions that affect the cesium precipitation kinetics.
Date: December 17, 1999
Creator: Barnes, M.J.
Object Type: Report
System: The UNT Digital Library
Examination of the Potential for Formation of Energetic Compounds in Dry Sludge (open access)

Examination of the Potential for Formation of Energetic Compounds in Dry Sludge

This report details initial results from an investigation of the potential formation and fate of energetic compounds in Savannah River Site sludge.
Date: December 17, 1998
Creator: Barnes, M.J.
Object Type: Report
System: The UNT Digital Library
Non-Destructive Evaluation of Wind Turbine Blades Using an Infrared Camera (open access)

Non-Destructive Evaluation of Wind Turbine Blades Using an Infrared Camera

The use of a digital infrared as a non-destructive evaluation thermography camera (NDE) tool was ex- plored in two separate wind turbine blade fatigue tests. The fwst test was a fatigue test of part of a 13.1 meter wood-epoxy-composite blade. The second test was on a 4.25 meter pultruded fiber glass blade section driven at several mechanical resonant frequencies. The digital infrared camera can produce images of either the static temperature distribution on the surface of the specimen, or the dynamic temperature distribution that is in phase with a specific frequency on a vibrating specimen. The dynamic temperature distribution (due to thermoplastic effects) gives a measure of the sum of the principal stresses at each point on the surface. In the wood- epoxy-composite blade fatigue test, the point of ultimate failure was detected long before failure occurred. The mode shapes obtained with the digital infrared camera, from the resonant blade tests, were in very good agree- ment with the finite-element calculations. In addition, the static temperature images of the resonating blade showed two areas that contained cracks. Close-up dy- namic inf%red images of these areas showed the crack structure that agreed with subsequent dye-penetrant analysis.
Date: December 17, 1998
Creator: Beattie, A. G. & Rumsey, M.
Object Type: Article
System: The UNT Digital Library
TTP SR1-6-WT-31, Milestone C.3-2 annual report on Clemson/INEEL melter work. Revision 1 (open access)

TTP SR1-6-WT-31, Milestone C.3-2 annual report on Clemson/INEEL melter work. Revision 1

This work is performed in collaboration with RL37WT31-C and ID77WT31-B. During the first two years of radioactive operation of the DWPF process, several areas for improvement in melter design have been identified. The continuing scope of this task is to address performance limitations and deficiencies identified by the user. SRS will design and test several configurations of the melter pour spout and associated equipment to improve consistency of performance and recommend design improvements.
Date: December 17, 1999
Creator: Bickford, D.F.
Object Type: Report
System: The UNT Digital Library
Automatic differentiation and Navier-Stokes. (open access)

Automatic differentiation and Navier-Stokes.

We describe the use of automatic differentiation (AD) to enhance a compressible Navier-Stokes model. With the solver, AD is used to accelerate convergence by more than an order of magnitude. Outside the solver, AD is used to compute the derivatives needed for optimization. We emphasize the potential for performance gains if the programmer does not treat AD as a black box, but instead utilizes high-level knowledge about the nature of the application.
Date: December 17, 1997
Creator: Bischof, C.; Hovland, P. & Mohammadi, B.
Object Type: Article
System: The UNT Digital Library
Selection of Models for Ingestion Pathway and Relocation Radii Determination (open access)

Selection of Models for Ingestion Pathway and Relocation Radii Determination

The distance at which intermediate phase protective actions (such as food interdiction and relocation) may be needed following postulated accidents at three Savannah River Site nonreactor nuclear facilities will be determined by modeling. The criteria used to select dispersion/deposition models are presented. Several models were considered, including ARAC, MACCS, HOTSPOT, WINDS (coupled with PUFF-PLUME), and UFOTRI. Although ARAC and WINDS are expected to provide more accurate modeling of atmospheric transport following an actual release, analyses consistent with regulatory guidance for planning purposes may be accomplished with comparatively simple dispersion models such as HOTSPOT and UFOTRI. A recommendation is made to use HOTSPOT for non-tritium facilities and UFOTRI for tritium facilities.
Date: December 17, 1998
Creator: Blanchard, A.
Object Type: Report
System: The UNT Digital Library
(Energy Efficiency of the Computerized Utilities Energy Monitor and Control System) (open access)

(Energy Efficiency of the Computerized Utilities Energy Monitor and Control System)

The travelers, representing the ORNL Energy Division, Efficiency and Renewables Research Section, conducted an in-depth evaluation of the CUMACS/EMCS installed at the 26th Support Group, USAREUR. This endeavor included an evaluation of the overall performance of this system including operations maintenance and end-user impact. System energy efficiency in terms of projected and actual energy and cost savings were analyzed. Conclusions and preliminary recommendations based on this evaluation were also formulated.
Date: December 17, 1990
Creator: Broders, M. A. & McConnell, B. W.
Object Type: Report
System: The UNT Digital Library
Reverse engineering: algebraic boundary representations to constructive solid geometry. (open access)

Reverse engineering: algebraic boundary representations to constructive solid geometry.

Recent advances in reverse engineering have focused on recovering a boundary representation (b-rep) of an object, often for integration with rapid prototyping. This boundary representation may be a 3-D point cloud, a triangulation of points, or piecewise algebraic or parametric surfaces. This paper presents work in progress to develop an algorithm to extend the current state of the art in reverse engineering of mechanical parts. This algorithm will take algebraic surface representations as input and will produce a constructive solid geometry (CSG) description that uses solid primitives such as rectangular block, pyramid, sphere, cylinder, and cone. The proposed algorithm will automatically generate a CSG solid model of a part given its algebraic b-rep, thus allowing direct input into a CAD system and subsequent CSG model generation.
Date: December 17, 1997
Creator: Buchele, S. F. & Ellingson, W. A.
Object Type: Article
System: The UNT Digital Library
Modeling atmospheric deposition using a stochastic transport model (open access)

Modeling atmospheric deposition using a stochastic transport model

An advanced stochastic transport model has been modified to include the removal mechanisms of dry and wet deposition. Time-dependent wind and turbulence fields are generated with a prognostic mesoscale numerical model and are used to advect and disperse individually released particles that are each assigned a mass. These particles are subjected to mass reduction in two ways depending on their physical location. Particles near the surface experience a decrease in mass using the concept of a dry deposition velocity, while the mass of particles located within areas of precipitation are depleted using a scavenging coefficient. Two levels of complexity are incorporated into the particle model. The simple case assumes constant values of dry deposition velocity and scavenging coefficient, while the more complex case varies the values according to meteorology, surface conditions, release material, and precipitation intensity. Instantaneous and cumulative dry and wet deposition are determined from the mass loss due to these physical mechanisms. A useful means of validating the model results is with data available from a recent accidental release of Cesium-137 from a steel-processing furnace in Algeciras, Spain in May, 1998. This paper describes the deposition modeling technique, as well as a comparison of simulated concentration and deposition …
Date: December 17, 1999
Creator: Buckley, R. L.
Object Type: Report
System: The UNT Digital Library
Amplitude and phase modulation with waveguide optics (open access)

Amplitude and phase modulation with waveguide optics

We have developed amplitude and phase modulation systems for glass lasers using integrated electro-optic modulators and solid state high- speed electronics. The present and future generation of lasers for Inertial Confinement Fusion require laser beams with complex temporal and phase shaping to compensate for laser gain saturation, mitigate parametric processes such as transverse stimulated Brillouin scattering in optics, and to provide specialized drive to the fusion targets. These functions can be performed using bulk optoelectronic modulators, however using high-speed electronics to drive low voltage integrated optical modulators has many practical advantages. In particular, we utilize microwave GaAs transistors to perform precision, 250 ps resolution temporal shaping. Optical bandwidth is generated using a microwave oscillator at 3 GHz amplified by a solid state amplifier. This drives an integrated electrooptic modulator to achieve laser bandwidths exceeding 30 GHz.
Date: December 17, 1996
Creator: Burkhart, S. C.; Wilcox, R. B.; Browning, D. & Penko, F. A.
Object Type: Article
System: The UNT Digital Library
Statement of work for conceptual design of solidified high-level waste interim storage system project (phase I) (open access)

Statement of work for conceptual design of solidified high-level waste interim storage system project (phase I)

The U.S. Department of Energy (DOE) has embarked upon a course to acquire Hanford Site tank waste treatment and immobilization services using privatized facilities. This plan contains a two phased approach. Phase I is a ``proof-of-principle/commercial demonstration- scale`` effort and Phase II is a full-scale production effort. In accordance with the planned approach, interim storage (IS) and disposal of various products from privatized facilities are to be DOE furnished. The path forward adopted for Phase I solidification HLW IS entails use of Vaults 2 and 3 in the Spent Nuclear Fuel Canister Storage Building, to be located in the Hanford Site 200 East Area. This Statement of Work describes the work scope to be performed by the Architect-Engineer to prepare a conceptual design for the solidified HLW IS System.
Date: December 17, 1996
Creator: Calmus, R. B.
Object Type: Report
System: The UNT Digital Library
On Constraints in Assembly Planning (open access)

On Constraints in Assembly Planning

Constraints on assembly plans vary depending on product, assembly facility, assembly volume, and many other factors. Assembly costs and other measures to optimize vary just as widely. To be effective, computer-aided assembly planning systems must allow users to express the plan selection criteria that appIy to their products and production environments. We begin this article by surveying the types of user criteria, both constraints and quality measures, that have been accepted by assembly planning systems to date. The survey is organized along several dimensions, including strategic vs. tactical criteria; manufacturing requirements VS. requirements of the automated planning process itself and the information needed to assess compliance with each criterion. The latter strongly influences the efficiency of planning. We then focus on constraints. We describe a framework to support a wide variety of user constraints for intuitive and efficient assembly planning. Our framework expresses all constraints on a sequencing level, specifying orders and conditions on part mating operations in a number of ways. Constraints are implemented as simple procedures that either accept or reject assembly operations proposed by the planner. For efficiency, some constraints are supplemented with special-purpose modifications to the planner's algorithms. Fast replanning enables an interactive plan-view-constrain-replan cycle that …
Date: December 17, 1998
Creator: Calton, T. L.; Jones, R. E. & Wilson, R. H.
Object Type: Article
System: The UNT Digital Library
Damage resistant optics for a mega-joule solid-state laser (open access)

Damage resistant optics for a mega-joule solid-state laser

Research on Inertial Confinement Fusion (ICF) has progressed rapidly in the past several years. As a consequence, LLNL is developing plans to upgrade the current 120 kJ solid state (Nd{sup +3}-phosphate glass) Nova laser to a 1.5 to 2 megajoule system with the goal of achieving fusion ignition. The design of the planned Nova Upgrade is briefly discussed. Because of recent improvements in the damage resistance of optical materials it is now technically and economically feasible to build a megajoule-class solid state laser. Specifically, the damage threshold of Nd{sup +3}-doped phosphate laser glass, multilayer dielectric coatings, and non-linear optical crystals (e.g., KDP) have been dramatically improved. These materials now meet the fluence requirements for a 1.5--2 MJ Nd{sup 3+}-glass laser operating at 1054 and 351 nm and at a pulse length of 3 ns. The recent improvements in damage thresholds are reviewed; threshold data at both 1064 and 355 nm and the measured pulse length scaling are presented. 20 refs., 9 figs., 2 tabs.
Date: December 17, 1990
Creator: Campbell, J.H.; Rainer, F.; Kozlowski, M.; Wolfe, C.R.; Thomas, I. & Milanovich, F.
Object Type: Article
System: The UNT Digital Library
Nonlinear interaction of fast particles with Alfven waves in toroidal plasmas (open access)

Nonlinear interaction of fast particles with Alfven waves in toroidal plasmas

A numerical algorithm to study the nonlinear, resonant interaction of fast particles with Alfven waves in tokamak geometry has been developed. The scope of the formalism is wide enough to describe the nonlinear evolution of fishbone modes, toroidicity-induced Alfven eigenmodes and ellipticity-induced Alfven eigenmodes, driven by both passing and trapped fast ions. When the instability is sufficiently weak, it is known that the wave-particle trapping nonlinearity will lead to mode saturation before wave-wave nonlinearities are appreciable. The spectrum of linear modes can thus be calculated using a magnetohydrodynamic normal-mode code, then nonlinearly evolved in time in an efficient way according to a two-time-scale Lagrangian dynamical wave model. The fast particle kinetic equation, including the effect of orbit nonlinearity arising from the mode perturbation, is simultaneously solved of the deviation, {delta}f = f {minus} f{sub 0}, from an initial analytic distribution f{sub 0}. High statistical resolution allows linear growth rates, frequency shifts, resonance broadening effects, and nonlinear saturation to be calculated quickly and precisely. The results have been applied to an ITER instability scenario. Results show that weakly-damped core-localized modes alone cause negligible alpha transport in ITER-like plasmas--even with growth rates one order of magnitude higher than expected values. However, the …
Date: December 17, 1996
Creator: Candy, J.; Borba, D.; Huysmans, G. T. A.; Kerner, W. & Berk, H. L.
Object Type: Report
System: The UNT Digital Library
Assessment of Neptunium, Americium, and Curium in the Savannah River Site Environment (open access)

Assessment of Neptunium, Americium, and Curium in the Savannah River Site Environment

A series of documents has been published in which the impact of various radionuclides released to the environment by Savannah River Site (SRS) operations has been assessed. The quantity released, the disposition of the radionuclides in the environment, and the dose to offsite individuals has been presented for activation products, carbon cesium, iodine, plutonium, selected fission products, strontium, technetium, tritium, uranium, and the noble gases. An assessment of the impact of nonradioactive mercury also has been published.This document assesses the impact of radioactive transuranics released from SRS facilities since the first reactor became operational late in 1953. The isotopes reported here are 239Np, 241Am, and 244Cm.
Date: December 17, 1997
Creator: Carlton, W.H.
Object Type: Report
System: The UNT Digital Library
Radioactive air emissions notice of construction use of a portable exhauster at 244-AR vault. Revision 2 (open access)

Radioactive air emissions notice of construction use of a portable exhauster at 244-AR vault. Revision 2

This document serves as a notice of construction (NOC), pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to construct, pursuant to 40 Code of Federal Regulations (CFR) 61.96, a portable exhauster at the 244-AR Vault. The exhauster would be used during air jetting of accumulated liquids from the cell sumps into the tanks and to make transfers among the tanks within the vault when needed. The 244-AR Vault is considered to be a double-contained receiver tank (OCRT) based on its functional characteristics, although it is not listed as one of the five designated DCRTs in the 200 Area Tank Farm systems. Process operations at the vault have been inactive since 1978 and the vault`s two stacks have not operated since 1993. Since cessation of vault operations an extremely large amount of rain water and snow melt have accumulated in the cell sumps. The water level in the sumps is substantially above their respective operating levels and there is concern for leakage to the environment through containment failure due to corrosion from backed-up sump liquid. Active ventilation is required to provide contamination control during air jetting operations within the vault. It has been …
Date: December 17, 1997
Creator: Carrell, D. J.
Object Type: Report
System: The UNT Digital Library
First and second quarters 1999 -- TNX Area groundwater and effectiveness monitoring strategy data only report (open access)

First and second quarters 1999 -- TNX Area groundwater and effectiveness monitoring strategy data only report

This report presents data of groundwater monitoring conducted during the first and second quarters of 1999 in support of the Interim Remedial Action. The data is from groundwater monitoring wells described in this report as the primary, secondary, and recovery wells of the initial operation of the Effectiveness Monitoring Strategy (EMS) as stipulated in Revision 1.3 (WSRC, 1996), the proposed wells for the full operation of the EMS as described in Revision 1.5 (WSRC, 1999), and general wells pertinent to the report. Also included are data from SRTC projects in the TNX Area that are deemed useful for groundwater characterization.
Date: December 17, 1999
Creator: Chase, J.
Object Type: Report
System: The UNT Digital Library
Trade Issues in the 103rd Congress (open access)

Trade Issues in the 103rd Congress

Trade and trade-related issues are prominent parts of the agenda of the 103rd Congress. The Congress has already acted on some issues, in particular the North American Free Trade Agreement (NAFTA). It will have to consider legislation to implement the trade agreements reached during the Uruguay Round of the GATT, which was completed on Dec. 15,1993.
Date: December 17, 1993
Creator: Cooper, William H.
Object Type: Report
System: The UNT Digital Library
Basement Surface Faulting and Topography for Savannah River Site and Vicinity (open access)

Basement Surface Faulting and Topography for Savannah River Site and Vicinity

This report integrates the data from more than 60 basement borings and over 100 miles of seismic reflection profiling acquired on the Savannah River Site to map the topography of the basement (unweathered rock) surface and faulting recorded on this surface.
Date: December 17, 1998
Creator: Cumbest, R.J.
Object Type: Report
System: The UNT Digital Library
Life-Cycle Cost and Risk Analysis of Alternative Configurations for Shipping Low-Level Radioactive Waste to the Nevada Test Site (open access)

Life-Cycle Cost and Risk Analysis of Alternative Configurations for Shipping Low-Level Radioactive Waste to the Nevada Test Site

The Nevada Test Site (NTS) is a major receiver of low-level radioactive waste (LLW) for disposal. Currently, all LLW received at NTS is shipped by truck. The trucks use highway routes to NTS that pass through the Las Vegas Valley and over Hoover Dam, which is a concern of local stakeholder groups in the State of Nevada. Rail service offers the opportunity to reduce transportation risks and costs, according to the Waste Management Programmatic Environmental Impact Statement (WM-PEIS). However, NTS and some DOE LLW generator sites are not served with direct rail service so intermodal transport is under consideration. Intermodal transport involves transport via two modes, in this case truck and rail, from the generator sites to NTS. LLW shipping containers would be transferred between trucks and railcars at intermodal transfer points near the LLW generator sites, NTS, or both. An Environmental Assessment (EA)for Intermodal Transportation of Low-Level Radioactive Waste to the Nevada Test Site (referred to as the NTSIntermodal -M) has been prepared to determine whether there are environmental impacts to alterations to the current truck routing or use of intermodal facilities within the State of Nevada. However, an analysis of the potential impacts outside the State of Nevada …
Date: December 17, 1999
Creator: Daling, PM; Ross, SB & Biwer, BM
Object Type: Report
System: The UNT Digital Library
Life-Cycle Cost and Risk Analysis of Alternative Configurations for Shipping Low-Level Radioactive Waste to the Nevada Test Site (open access)

Life-Cycle Cost and Risk Analysis of Alternative Configurations for Shipping Low-Level Radioactive Waste to the Nevada Test Site

This study evaluates alternative transportation system configurations for NTS approved and potential generators based on complex-wide LLW load information. Technical judgments relative to the availability of DOE LLW generators to ship from their sites by rail were developed. Public and worker risk and life-cycle cost components are quantified. The study identifies and evaluates alternative scenarios that increase the use of rail (intermodal where needed) to transport LLW from generator sites to NTS.
Date: December 17, 1999
Creator: Daling, Philip M.; Ross, Steven B. & Biwer, Bruce
Object Type: Report
System: The UNT Digital Library
EQPT, a data file preprocessor for the EQ3/6 software package: User`s guide and related documentation (Version 7.0); Part 2 (open access)

EQPT, a data file preprocessor for the EQ3/6 software package: User`s guide and related documentation (Version 7.0); Part 2

EQPT is a data file preprocessor for the EQ3/6 software package. EQ3/6 currently contains five primary data files, called datao files. These files comprise alternative data sets. These data files contain both standard state and activity coefficient-related data. Three (com, sup, and nea) support the use of the Davies or B-dot equations for the activity coefficients; the other two (hmw and pit) support the use of Pitzer`s (1973, 1975) equations. The temperature range of the thermodynamic data on these data files varies from 25{degrees}C only to 0-300{degrees}C. The principal modeling codes in EQ3/6, EQ3NR and EQ6, do not read a data0 file, however. Instead, these codes read an unformatted equivalent called a data1 file. EQPT writes a datal file, using the corresponding data0 file as input. In processing a data0 file, EQPT checks the data for common errors, such as unbalanced reactions. It also conducts two kinds of data transformation. Interpolating polynomials are fit to data which are input on temperature adds. The coefficients of these polynomials are then written on the datal file in place of the original temperature grids. A second transformation pertains only to data files tied to Pitzer`s equations. The commonly reported observable Pitzer coefficient parameters …
Date: December 17, 1992
Creator: Daveler, S.A. & Wolery, T.J.
Object Type: Report
System: The UNT Digital Library