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TORO II simulations of induction heating in ferromagnetic materials

Description: TORO II is a finite element computer program that is used in the simulation of electric and magnetic fields. This code, which was developed at Sandia National Laboratories, has been coupled with a finite element thermal code, COYOTE II, to predict temperature profiles in inductively heated parts. The development of an effective technique to account for the nonlinear behavior of the magnetic permeability in ferromagnetic parts is one of the more difficult aspects of solving induction heating problems. In the TORO II code, nonlinear, spatially varying magnetic permeability is approximated by an effective permeability on an element-by-element basis that effectively provides the same energy deposition that is produced when the true permeability is used. This approximation has been found to give an accurate estimate of the volumetric heating distribution in the part, and predicted temperature distributions have been experimentally verified using a medium carbon steel and a 10kW industrial induction heating unit. Work on the model was funded through a Cooperative Research and Development Agreement (CRADA) between the Department of Energy and General Motors` Delphi Saginaw Steering Systems.
Date: September 1, 1997
Creator: Adkins, D.R.; Gartling, D.K.; Kelley, J.B. & Kahle, P.M.
Partner: UNT Libraries Government Documents Department

Technical Support Section annual work plan for FY 1998

Description: The Technical Support Section (TSS) of the Instrumentation and Controls (I and C) Division of Oak Ridge National Laboratory (ORNL) provides technical services such as fabrication, modification, installation, calibration, operation, repair, and preventive maintenance of instruments and other related equipment. Because the activities and priorities of TSS must be adapted to the technical support needs of ORNL, the TSS Annual Work Plan is derived from, and is driven directly by, current trends in the budgets and activities of each ORNL division for which TSS provides support. Trends that will affect TSS planning during this period are reductions in the staffing levels of some R and D programs because of attrition or budget cuts. TSS does not have an annual budget to cover operating expenses incurred in providing instrument maintenance support to ORNL. Each year, TSS collects information concerning the projected funding levels of programs and facilities it supports. TSS workforce and resource projections are based on the information obtained and are weighted depending on the percentage of support provided to that division or program. Each year, TSS sets the standard hourly charge rate for the following fiscal year. The Long-Range Work Plan is based on estimates of the affects of the long-range priorities and directions of the Laboratory. Proposed new facilities and programs provide additional bases for long-range planning. After identifying long-range initiatives, TSS planning includes future training requirements, reevaluation of qualifications for new hires, and identification of essential test equipment that will be needed for new work.
Date: December 1, 1997
Creator: Adkisson, B.P.; Allison, K.L.; Effler, R.P.; Hess, R.A.; Keeble, T.A.; Odom, S.M. et al.
Partner: UNT Libraries Government Documents Department

303-K Storage facility sampling and analysis plan

Description: This document describes the cleanup, sampling, and analysis activities associated with the closure of the 303-K Storage Facility under the Washington Administrative Code (WAC) 173-303-610, ``Dangerous Waste Regulations.`` this document is a supplement to the 303-K Storage Facility Closure Plan (DOE-RL 1995a) (Closure Plan). The objective of these activities is to support clean closure of the 303 K Storage Facility. This document defines the information and activities needed to meet this objective, including: constituents of concern, cleanup performance standards, cleanup activities, sampling locations and methods, field screening locations and methods, field quality control requirements, laboratory analytical methods, and data validation methodology. This document supersedes the Closure Plan if the two conflict
Date: July 1, 1997
Creator: Adler, J.G.
Partner: UNT Libraries Government Documents Department

Nonlinear viscoelastic response of carbon black-filled butyl rubber and implications for o-ring aging

Description: Butyl rubber, unfortunately, has pronounced nonlinear viscoelastic behavior, which may be modelled by a separable KBKZ formalism. While these effects seem to have minimal impact on accelerated sealing force measurements, they do severely impact compression set tests. Therefore, a new test is suggested for evaluating field-return o-rings which is free from such confounding effects.
Date: November 1, 1997
Creator: Adolf, D.
Partner: UNT Libraries Government Documents Department

Viscosities of epoxy encapsulants

Description: The temperature, curing, and filler dependencies of the viscosities of common epoxies used at Sandia encapsulants are presented along with examples of useful applications.
Date: November 1, 1997
Creator: Adolf, D.; Strommen, R. & Johnson, H.
Partner: UNT Libraries Government Documents Department

Correlation of the crack initiation stress with epoxy network topology

Description: Much controversy surrounds the dependence of stress intensity factor of glassy thermosets, epoxies in particular, with crosslink density. One could scan the literature and find references that claim K{sub Ic} increases with crosslink density, decreases with crosslink density, or is independent of crosslink density. The authors feel that two factors contribute to this confusion. First, a typical method for assessing this dependence relies on modifying the crosslink density by changing the precursor epoxy molecular weight. On the other hand, one could change stoichiometry or quench the reaction at intermediate extents of reaction to obtain large changes in crosslink density. However, most studies have not measured the resulting stress intensity factor of these partially cured systems at constant T-T{sub g}, where T{sub g} is the glass transition temperature of the epoxy. Since T{sub g} can change significantly with cure and since fracture processes at the crack tip are dissipative, they must work at constant T-T{sub g} to ensure that the nonlinear viscoelastic mechanisms are fairly compared. In this study, they quenched the reaction of the diglycidyl ether of bisphenol A (DGEBA) and diethanolamine (DEA) at various stages past the gel point and measured the three-point-bend stress intensity factor at a constant T-T{sub g} = {minus}50 C. The trend is clear and significant; increasing crosslink density directly increases the load-to-fail.
Date: March 1, 1997
Creator: Adolf, D.; Weeks, T. & McCoy, J.
Partner: UNT Libraries Government Documents Department

Beam loading compensation in the NLCTA

Description: In the design of the Next Linear Collider (NLC), multi-bunch operation is employed to improve efficiency at the cost of substantial beam loading. The RF pulse that powers the accelerator structures will be shaped to compensate for the effect of the transient loading along the bunch train. This scheme has been implemented in the Next Linear Collider Test Accelerator (NLCTA), a facility built to test the key accelerator technology of the NLC. In this paper the authors describe the compensation method, the techniques used to measure the energy variation along the bunch train, and results from tests with NLC-like beam currents.
Date: May 1, 1997
Creator: Adolphsen, C.; Lavine, T.; Nantista, C.; Ruth, R.; Wang, J. & Yeremian, D.
Partner: UNT Libraries Government Documents Department

Corrosion of AB{sub 5} metal hydride electrodes

Description: Metal hydride electrodes are an attractive substitute for the cadmium electrode in Cd/Ni batteries because of their relatively benign environmental impact and higher energy density. However, even though MH{sub x}/Ni batteries are currently competitive in certain applications, their full potential as cheap, reliable, energy storage devices is not yet realized: a severe penalty has been incurred in storage capacity and materials costs in order to inhibit corrosion and attain acceptable electrode cycle life. Currently there are two types of alloys which are useful as metal hydride electrodes, the AB{sub 5} and the AB{sub 2} classes of intermetallic compounds. Commercial AB{sub 5} electrodes use mischmetal, a low cost combination of rare earth elements. The B{sub 5} component remains primarily Ni but is substituted in part with Co, Mn, Al etc. The partial substitution of Ni increases thermodynamic stability of the hydride phase and corrosion resistance. Such an alloy is commonly written as MmB{sub 5} where Mm represents the mischmetal component; the B{sub 5} composition in commercial batteries is variable but electrodes consisting of MmNi{sub 3.55}Co{sub .75}Mn{sub .4}Al{sub .3} have good storage capacity and cycle life and most AB{sub 5} battery electrodes have a similar composition. The authors have been concerned with the function that individual components play in such an alloy with respect to lattice expansion, hydride stability, and surface passivation. Thus they have focused on the properties of a similar alloy, A(NiCoMnAl){sub 5} where A is La or La{sub 1{minus}x}Ce{sub x}. Some of their results noted here have previously appeared in separate publications; the purpose of this paper is to combine them with new data to give a more coherent and complete whole.
Date: November 1, 1997
Creator: Adzic, G.D.; Johnson, J.R.; Mukerjee, S.; McBreen, J. & Reilly, J.J.
Partner: UNT Libraries Government Documents Department

Large-scale structure evolution in axisymmetric, compressible free-shear layers

Description: This paper is a description of work-in-progress. It describes Sandia`s program to study the basic fluid mechanics of large-scale mixing in unbounded, compressible, turbulent flows, specifically, the turbulent mixing of an axisymmetric compressible helium jet in a parallel, coflowing compressible air freestream. Both jet and freestream velocities are variable over a broad range, providing a wide range mixing layer Reynolds number. Although the convective Mach number, M{sub c}, range is currently limited by the present nozzle design to values of 0.6 and below, straightforward nozzle design changes would permit a wide range of convective Mach number, to well in excess of 1.0. The use of helium allows simulation of a hot jet due to the large density difference, and also aids in obtaining optical flow visualization via schlieren due to the large density gradient in the mixing layer. The work comprises a blend of analysis, experiment, and direct numerical simulation (DNS). There the authors discuss only the analytical and experimental efforts to observe and describe the evolution of the large-scale structures. The DNS work, used to compute local two-point velocity correlation data, will be discussed elsewhere.
Date: May 1, 1997
Creator: Aeschliman, D.P. & Baty, R.S.
Partner: UNT Libraries Government Documents Department

Experimental methodology for computational fluid dynamics code validation

Description: Validation of Computational Fluid Dynamics (CFD) codes is an essential element of the code development process. Typically, CFD code validation is accomplished through comparison of computed results to previously published experimental data that were obtained for some other purpose, unrelated to code validation. As a result, it is a near certainty that not all of the information required by the code, particularly the boundary conditions, will be available. The common approach is therefore unsatisfactory, and a different method is required. This paper describes a methodology developed specifically for experimental validation of CFD codes. The methodology requires teamwork and cooperation between code developers and experimentalists throughout the validation process, and takes advantage of certain synergisms between CFD and experiment. The methodology employs a novel uncertainty analysis technique which helps to define the experimental plan for code validation wind tunnel experiments, and to distinguish between and quantify various types of experimental error. The methodology is demonstrated with an example of surface pressure measurements over a model of varying geometrical complexity in laminar, hypersonic, near perfect gas, 3-dimensional flow.
Date: September 1, 1997
Creator: Aeschliman, D.P. & Oberkampf, W.L.
Partner: UNT Libraries Government Documents Department

Coherent structures in compressible free-shear-layer flows

Description: Large scale coherent structures are intrinsic fluid mechanical characteristics of all free-shear flows, from incompressible to compressible, and laminar to fully turbulent. These quasi-periodic fluid structures, eddies of size comparable to the thickness of the shear layer, dominate the mixing process at the free-shear interface. As a result, large scale coherent structures greatly influence the operation and efficiency of many important commercial and defense technologies. Large scale coherent structures have been studied here in a research program that combines a synergistic blend of experiment, direct numerical simulation, and analysis. This report summarizes the work completed for this Sandia Laboratory-Directed Research and Development (LDRD) project.
Date: August 1, 1997
Creator: Aeschliman, D.P.; Baty, R.S.; Kennedy, C.A. & Chen, J.H.
Partner: UNT Libraries Government Documents Department

Use of shear-stress-sensitive, temperature-insensitive liquid crystals for hypersonic boundary-layer transition detection

Description: The use of shear-stress-sensitive, temperature-insensitive (SSS/TI) liquid crystals (LCs) has been evaluated as a boundary-layer transition detection technique for hypersonic flows. Experiments were conducted at Mach 8 in the Sandia National Laboratories Hypersonic Wind Tunnel using a flat plate model at near zero-degree angle of attack over the freestream unit Reynolds number range 1.2-5.8x10{sup 6}/ft. Standard 35mm color photography and Super VHS color video were used to record LC color changes due to varying surface shear stress during the transition process for a range of commercial SSS liquid crystals. Visual transition data were compared to an established method using calorimetric surface heat-transfer measurements to evaluate the LC technique. It is concluded that the use of SSS/TI LCs can be an inexpensive, safe, and easy to use boundary-layer transition detection method for hypersonic flows. However, a valid interpretation of the visual records requires careful attention to illumination intensity levels and uniformity, lighting and viewing angles, some prior understanding of the general character of the flow, and the selection of the appropriate liquid crystal for the particular flow conditions.
Date: April 1, 1997
Creator: Aeschliman, D.P.; Croll, R.H. & Kuntz, D.W.
Partner: UNT Libraries Government Documents Department

Photo- and Electroproduction of J{sup PC} = 1 {sup {-+}} exotics

Description: The authors estimate the kinematic dependence of the exclusive photo- and electroproduction of J{sup PC} = 1{sup {-+}} exotic mesons due to {pi} exchange. They show that the kinematic dependence is largely independent of the exotic meson form factor, which is explicitly derived for a 1{sup {-+}} isovector hybrid meson in the flux-tube model of Isgur and Paton. The relevance to experiments currently planned at Jefferson Lab is indicated.
Date: December 1, 1997
Creator: Afanasev, Andrei & Page, Philip R.
Partner: UNT Libraries Government Documents Department

Relativistic charge form factor of the deuteron

Description: Relativistic integral representation in terms of experimental neutron-proton scattering phase shifts alone is used to compute the charge form factor of the deuteron G{sub Cd}(Q{sup 2}). The results of numerical calculations of {vert_bar}G{sub Cd}(Q{sup 2}){vert_bar} are presented in the interval of the four-momentum transfers squared 0 {<=} Q{sup 2} {<=} 35 fm{sup {minus}2}. Zero and the prominent secondary maximum in {vert_bar}G{sub Cd}(Q{sup 2}){vert_bar} are the direct consequences of the change of sign in the experimental {sup 3}S{sub 1} - phase shifts. Till the point Q{sup 2} {approx_equal} 20 fm{sup {minus}2} the total relativistic correction to {vert_bar}G{sub Cd}(Q{sup 2}){vert_bar} is positive and reaches the maximal value of 25% at Q{sup 2} {approx_equal} 14 fm{sup {minus}2}.
Date: December 1, 1997
Creator: Afanasev, Andrei V.; Afanasev, V.D. & Trubnikov, S.V.
Partner: UNT Libraries Government Documents Department

Measuring polarized gluon and quark distributions with meson photoproduction

Description: The authors calculate polarization asymmetries in photoproduction of high transverse momentum mesons, focusing on charged pions, considering the direct, fragmentation, and resolved photon processes. The results at very high meson momentum measure the polarized quark distributions and are sensitive to differences among the existing models. The results at moderate meson momentum are sensitive to the polarized gluon distribution and can provide a good way to measure it. Suitable data may come as a by-product of deep inelastic experiments to measure g{sub 1} or from dedicated experiments.
Date: June 1, 1997
Creator: Afanasev, Andrei; Carlson, Carl E. & Wahlquist, Christian
Partner: UNT Libraries Government Documents Department

Probing polarized parton distributions with meson photoproduction

Description: Polarization asymmetries in photoproduction of high transverse momentum mesons are a flavor sensitive way to measure the polarized quark distributions. the authors calculate the expected asymmetries in several models, and find that the asymmetries are significant and also significantly different from model to model. Suitable data may come as a by-product of deep inelastic experiments to measure g{sub 1} or from dedicated experiments.
Date: January 1, 1997
Creator: Afanasev, Andrei; Carlson, Carl E. & Wahlquist, Christian
Partner: UNT Libraries Government Documents Department

Boron-enhanced-diffusion of boron: The limiting factor for ultra-shallow junctions

Description: Reducing implant energy is an effective way to eliminate transient enhanced diffusion (TED) due to excess interstitials from the implant. It is shown that TED from a fixed Si dose implanted at energies from 0.5 to 20 keV into boron doping-superlattices decreases linearly with decreasing Si ion range, virtually disappearing at sub-keV energies. However, for sub-keV B implants diffusion remains enhanced and x{sub j} is limited to {ge} 100 nm at 1,050 C. The authors term this enhancement, which arises in the presence of B atomic concentrations at the surface of {approx} 6%, Boron-Enhanced-Diffusion (BED).
Date: December 1, 1997
Creator: Agarwal, A.; Eaglesham, D.J.; Gossmann, H.J.; Pelaz, L.; Herner, S.B.; Jacobson, D.C. et al.
Partner: UNT Libraries Government Documents Department

Report to users of ATLAS

Description: This report covers the following topics: (1) status of the ATLAS accelerator; (2) progress in R and D towards a proposal for a National ISOL Facility; (3) highlights of recent research at ATLAS; (4) the move of gammasphere from LBNL to ANL; (5) Accelerator Target Development laboratory; (6) Program Advisory Committee; (7) ATLAS User Group Executive Committee; and (8) ATLAS user handbook available in the World Wide Web. A brief summary is given for each topic.
Date: March 1, 1997
Creator: Ahmad, I. & Glagola, B.
Partner: UNT Libraries Government Documents Department

Microwave joining of SiC ceramics and composites

Description: Potential applications of SiC include components for advanced turbine engines, tube assemblies for radiant burners and petrochemical processing and heat exchangers for high efficiency electric power generation systems. Reliable methods for joining SiC are required in order to cost-effectively fabricate components for these applications from commercially available shapes and sizes. This manuscript reports the results of microwave joining experiments performed using two different types of SiC materials. The first were on reaction bonded SiC, and produced joints with fracture toughness equal to or greater than that of the base material over an extended range of joining temperatures. The second were on continuous fiber-reinforced SiC/SiC composite materials, which were successfully joined with a commercial active brazing alloy, as well as by using a polymer precursor.
Date: April 1, 1997
Creator: Ahmad, I.; Silberglitt, R.; Tian, Y.L. & Katz, J.D.
Partner: UNT Libraries Government Documents Department

Management plan for White Oak Dam. Revision 1

Description: The purpose is to provide operation and maintenance, periodic inspection, and emergency action plans for White Oak Dam in general accordance with the Federal Emergency Management Agency (FEMA) guidelines for dam safety. It must be understood that operations at the site are primarily for purposes of environmental monitoring, environmental protection and waste management operations control. Effluent is generally allowed to flow from the lake at its natural rate by rising above the broad crested weir notch elevation of 744 feet m.s.l.
Date: March 1, 1997
Creator: Ahmed, S.B.
Partner: UNT Libraries Government Documents Department

A new and superior ultrafine cementitious grout

Description: Sealing fractures in nuclear waste repositories concerns all programs investigating deep burial as a means of disposal. Because the most likely mechanism for contaminant migration is by dissolution and movement through groundwater, sealing programs are seeking low-viscosity sealants that are chemically, mineralogically, and physically compatible with the host rock. This paper presents the results of collaborative work directed by Sandia National Laboratories (SNL) and supported by Whiteshell Laboratories, operated by Atomic Energy of Canada, Ltd. The work was undertaken in support of the Waste Isolation Pilot Plant (WIPP), an underground nuclear waste repository located in a salt formation east of Carlsbad, NM. This effort addresses the technology associated with long-term isolation of nuclear waste in a natural salt medium. The work presented is part of the WIPP plugging and sealing program, specifically the development and optimization of an ultrafine cementitious grout that can be injected to lower excessive, strain-induced hydraulic conductivity in the fractured rock termed the Disturbed Rock Zone (DRZ) surrounding underground excavations. Innovative equipment and procedures employed in the laboratory produced a usable cement-based grout; 90% of the particles were smaller than 8 microns and the average particle size was 4 microns. The process involved simultaneous wet pulverization and mixing. The grout was used for a successful in situ test underground at the WIPP. Injection of grout sealed microfractures as small as 6 microns (and in one rare instance, 3 microns) and lowered the gas transmissivity of the DRZ by up to three orders of magnitude. Following the WIPP test, additional work produced an improved version of the grout containing particles 90% smaller than 5 microns and averaging 2 microns. This grout will be produced in dry form, ready for the mixer.
Date: April 1, 1997
Creator: Ahrens, E.H.
Partner: UNT Libraries Government Documents Department

Case study: Wildfire visualization

Description: The ability to forecast the progress of crisis events would significantly reduce human suffering and loss of life, the destruction of property, and expenditures for assessment and recovery. Los Alamos National Laboratory has established a scientific thrust in crisis forecasting to address this national challenge. In the initial phase of this project, scientists at Los Alamos are developing computer models to predict the spread of a wildfire. Visualization of the results of the wildfire simulation will be used by scientists to assess the quality of the simulation and eventually by fire personnel as a visual forecast of the wildfire`s evolution. The fire personnel and scientists want the visualization to look as realistic as possible without compromising scientific accuracy. This paper describes how the visualization was created, analyzes the tools and approach that was used, and suggests directions for future work and research.
Date: November 1, 1997
Creator: Ahrens, J.; McCormick, P.; Bossert, J.; Reisner, J. & Winterkamp, J.
Partner: UNT Libraries Government Documents Department

A distributed computing environment with support for constraint-based task scheduling and scientific experimentation

Description: This paper describes a computing environment which supports computer-based scientific research work. Key features include support for automatic distributed scheduling and execution and computer-based scientific experimentation. A new flexible and extensible scheduling technique that is responsive to a user`s scheduling constraints, such as the ordering of program results and the specification of task assignments and processor utilization levels, is presented. An easy-to-use constraint language for specifying scheduling constraints, based on the relational database query language SQL, is described along with a search-based algorithm for fulfilling these constraints. A set of performance studies show that the environment can schedule and execute program graphs on a network of workstations as the user requests. A method for automatically generating computer-based scientific experiments is described. Experiments provide a concise method of specifying a large collection of parameterized program executions. The environment achieved significant speedups when executing experiments; for a large collection of scientific experiments an average speedup of 3.4 on an average of 5.5 scheduled processors was obtained.
Date: April 1, 1997
Creator: Ahrens, J.P.; Shapiro, L.G. & Tanimoto, S.L.
Partner: UNT Libraries Government Documents Department

Biometric identification devices -- Laboratory testing vs. real life

Description: For over fifteen years Sandia National Laboratories has been involved in laboratory testing of biometric identification devices. The key concept of biometric identification devices is the ability for the system to identify some unique aspect of the individual rather than some object a person may be carrying or some password they are required to know. Tests were conducted to verify manufacturer`s performance claims, to determine strengths/weaknesses of devices, and to determine devices that meet the US Department of energy`s needs. However, during recent field installation, significantly different performance was observed than was predicted by laboratory tests. Although most people using the device believed it operated adequately, the performance observed was over an order of magnitude worse than predicted. The search for reasons behind this gap between the predicted and the actual performance has revealed many possible contributing factors. As engineers, the most valuable lesson to be learned from this experience is the value of scientists and engineers with (1) common sense, (2) knowledge of human behavior, (3) the ability to observe the real world, and (4) the capability to realize the significant differences between controlled experiments and actual installations.
Date: May 1, 1997
Creator: Ahrens, J.S.
Partner: UNT Libraries Government Documents Department