UNT Libraries Government Documents Department - 16 Matching Results

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Alignment and micro-inspection system

Description: A video microscope system has been designed and installed in the C-tank, a 3-g, high-explosive firing chamber in HEAF (High Explosives Applications Facility in LLNL). This microscope system helps a great deal, not only for precision alignment of the laser beam on the minute target for the Fabry-Perot velocimeter, but also for in situ inspection of the target before and after the experiment. In addition, the video information can also be stored in the PC computer as database documentati
Date: September 15, 1998
Creator: Chau, H; Hodgin, R L & Moua, K

Application of system simulation for engineering the technical computing environment of the Lawrence Livermore National Laboratorie

Description: This report summarizes an investigation performed by Lawrence Livermore National Laboratory� s (LLNL) Scientific Computing & Communications Department (SCCD) and the Garland Location of Raytheon Systems Company (RSC) from April through August.1998. The study assessed the applicability and benefits of utilizing System Simulation in architecting and deploying technical computing assets at LLNL, particularly in support of the ASCI program and associated scientific computing needs. The recommendations and other reported findings reflect the consensus of the investigation team. The investigation showed that there are potential benefits to performing component level simulation within SCCD in support of the ASCI program. To illustrate this, a modeling exercise was conducted by the study team that generated results consistent with measured operational performance. This activity demonstrated that a relatively modest effort could improve the toolset for making architectural trades and improving levels of understanding for managing operational practices. This capability to evaluate architectural trades was demonstrated by evaluating some of the productivity impacts of changing one of the design parameters of an existing file transfer system. The use of system simulation should be tailored to the local context of resource requirements/limitations, technology plans/processes/issues, design and deployment schedule, and organizational factors. In taking these matters into account, we recommend that simulation modeling be employed within SCCD on a limited basis for targeted engineering studies, and that an overall performance engineering program be established to better equip the Systems Engineering organization to direct future architectural decisions and operational practices. The development of an end-to-end modeling capability and enterprise-level modeling system within SCCD is not warranted in view of the associated development requirements and difficulty in determining firm operational performance requirements in advance of the critical architectural decisions. These recommendations also account for key differences between the programmatic and institutional environments at LLNL and RSC.
Date: September 15, 1998
Creator: Boyd, V; Edmunds, T; Minuzzo, K; Powell, E & Roche, L

Comparison of natural convection heat exchangers for solar water heating systems

Description: Thermosyphon heat exchangers are used in indirect solar water heating systems to avoid using a pump to circulate water from the storage tank to the heat exchanger. In this study, the authors consider the effect of heat exchanger design on system performance. They also compare performance of a system with thermosyphon flow to the same system with a 40W pump in the water loop. In the first part of the study, the authors consider the impact of heat exchanger design on the thermal performance of both one- and two-collector solar water heaters. The comparison is based on Solar Rating and Certification Corporation (SRCC) OG300 simulations. The thermosyphon heat exchangers considered are (1) a one-pass, double wall, 0.22 m{sup 2}, four tube-in-shell heat exchanger manufactured by AAA Service and Supply, Inc., (the Quad-Rod); (2) a two-pass, double wall, 0.2 m{sup 2}, tube-in-shell made by Heliodyne, Inc., but not intended for commercial development; (3) a one-pass, single wall, 0.28 m{sup 2}, 31 tube-in-shell heat exchanger from Young Radiator Company, and (4) a one-pass single-wall, 0.61 m{sup 2}, four coil-in-shell heat exchanger made by ThermoDynamics Ltd. The authors compare performance of the systems with thermosyphon heat exchangers to a system with a 40 W pump used with the Quad-Rod heat exchanger. In the second part of the study, the effects of reducing frictional losses through the heat exchanger and/or the pipes connecting the heat exchanger to the storage tank, and increasing heat transfer area are evaluated in terms of OG300 ratings.
Date: September 15, 1998
Creator: Davidson, J. & Liu, W.

Decontamination of Radionuclides from Concrete During and After Thermal Treatment

Description: The objective was to clarify from the theoretical viewpoint the mechanical, diffusional, thermodynamic and electromagnetic aspects of the decontaminations problem, by means of developing a powerful computational model to evaluate the effect of a very rapid heating regime on the on the contaminated concrete walls or slabs. The practical objective was to assess the feasibility of the microwave heating scheme envisaged and determine its suitable parameters such as power and duration. This objective was complementary to, but separate from, the chemical and nuclear aspects of long-time processes that led to the contamination and various conceivable alternative methods of decontamination which were investigated by Dr. Brian Spalding of Oak Ridge National Laboratory, with whom the start-up phase of this project was coordinated.
Date: September 15, 1998
Creator: Bazant, Z. P.

[Develop mine communications system]. Final technical report

Description: The objective of this project was to develop, design, and build a system prototype to demonstrate the practicality of two-way, wireless through-the-earth communications between the interior of a mine and the surface. The system was to communicate data for process and environment monitoring and control, and provide real-time voice communication for emergency situations and for daily operations use. Transmitters and receivers were designed, built, and tested in actual mines. A wireless in-mine communications system was also developed. The feasibility of the concept and the marketability of the product were successfully demonstrated. Additional work must be done to make the product suitable for, and marketable to, the coal mining industry.
Date: September 15, 1998
Creator: Meiksin, Z.H.

Dickinson Pure Air Combustion ERIP technical progress report number 4 [for the reporting period 7/98 through 9/98]

Description: Research was focused on work done to date and melding with current market conditions and demand. The overall objective of this program is to demonstrate the feasibility of EnerTech`s combustion technology to produce clean energy efficiently and cost effectively from coal and/or other char slurry fuels. From the data generated in this project, EnerTech will be able to conduct preliminary engineering design work for a process development unit. The design work included simulations that optimize process cycle efficiency, and includes analysis of process temperature, pressures, and mass/energy flows. The overall goal is to conduct the research necessary to launch a commercial process. Market surveys indicated that stand-alone systems would not find a near-term market; therefore, the company is concentrating on a configuration that includes a process that first generates a slurry char product.
Date: September 15, 1998
Creator: Klosky, M.

An Efficient Molecular Dynamics Scheme for Predicting Dopant Implant Profiles in Semiconductors

Description: The authors present a highly efficient molecular dynamics scheme for calculating the concentration profile of dopants implanted in group-IV alloy, and III-V zinc blende structure materials. The program incorporates methods for reducing computational overhead, plus a rare event algorithm to give statistical accuracy over several orders of magnitude change in the dopant concentration. The code uses a molecular dynamics (MD) model, instead of the binary collision approximation (BCA) used in implant simulators such as TRIM and Marlowe, to describe ion-target interactions. Atomic interactions are described by a combination of 'many-body' and screened Coulomb potentials. Inelastic energy loss is accounted for using a Firsov model, and electronic stopping is described by a Brandt-Kitagawa model which contains the single adjustable parameter for the entire scheme. Thus, the program is easily extensible to new ion-target combinations with the minimum of tuning, and is predictive over a wide range of implant energies and angles. The scheme is especially suited for calculating profiles due to low energy, large angle implants, and for situations where a predictive capability is required with the minimum of experimental validation. They give examples of using their code to calculate concentration profiles and 2D 'point response' profiles of dopants in crystalline silicon, silicon-germanium blends, and gallium-arsenide. They can predict the experimental profiles over five orders of magnitude for <100> and <110> channeling and for non-channeling implants at energies up to hundreds of keV.
Date: September 15, 1998
Creator: Beardmore, K.M. & Gronbech-Jensen, N.

Fast-Track Trade Negotiating Authority: A Comparison of 105th Congress Legislative Proposals

Description: This report provides a side-by-side comparison of H.R. 2621 and S. 2400, as reported, 105th Congress bills that would provide the President with trade negotiating authority and accord certain resulting agreements and implementing bills expedited -- or "fast-track" -- legislative consideration.
Date: September 15, 1998
Creator: Grimmett, Jeanne J.

Final Report: Computer Games to Teach Geography: El Nino: Mysteries of the Pacific and Mysteries of the Antarctic, August 15, 1994 - June 20, 1998

Description: During the period covered by this project we have accomplished all the objectives described in our original proposal. The main achievement, however, has been to bring to the commercial market an excellent quality education software product. This highest level of quality has been recognized by the Software Publisher Association, which has awarded its most prestigious appreciation, the Codie Award, for our first product Ocean Expeditions: El Nino. With regards to commercialization, we have developed, as a Phase III project, a comprehensive business plan which we have used to find a publisher/distributor of our products (Tom Snyder Productions) and are presently updating to raise private funding. Also, we have been awarded a 5-year Cooperative Agreement by NASA to continue the development of our products and bring five new products to the education market by the early part of the millennium.
Date: September 15, 1998
Creator: Gautier-Downes, Catherine

Managing America's solid waste

Description: This report presents an historical overview of the federal role in municipal solid waste management from 1965 to approximately 1995. Attention is focuses on the federal role in safeguarding public health, protecting the environment, and wisely using material and energy resources. It is hoped that this report will provide important background for future municipal solid waste research and development initiatives.
Date: September 15, 1998
Creator: Phillips, J. A.

MCFC component development at ANL.

Description: Argonne National Laboratory is developing advanced cathode and electrolyte components for the molten carbonate fuel cell (MCFC). Working in support of the MCFC developers, the goal of this effort is to extend the life of the MCFC cell and to improve its performance.
Date: September 15, 1998
Creator: Bloom, I.

Status and update of the National Ignition Facility radiation effects testing program

Description: We are progressing in our efforts to make the National Ignition Facility (NIF) available to the nation as a radiation effects simulator to support the Services needs for nuclear hardness and survivability testing and validation. Details of our program were summarized in a paper presented at the 1998 HEART Conference. This paper describes recent activities and up-dates plans for NIF radiation effects testing.
Date: September 15, 1998
Creator: Davis, J; Serduke, F & Wuest, C R

Structure of parallel-velocity-shear driven mode in toroidal plasmas

Description: It is shown that the Fourier-ballooning representation is appropriate for the study of short wavelength drift-like perturbation in toroidal plasmas with a parallel velocity shear (PVS). The radial structure of the mode driven by a PVS is investigated in a torus. The Reynolds stress created by PVS turbulence and proposed as one of the sources for a sheared poloidal plasma rotation is analyzed. It is demonstrated that a finite ion temperature may strongly enhance the Reynolds stress creation ability from PVS driven turbulence. The correlation of this observation with the requirement that ion heating power be higher than a threshold value for the formation of an internal transport barrier is discussed.
Date: September 15, 1998
Creator: Dong, J.Q.; Xu, W.B.; Zhang, Y.Z. & Horton, W.

TAE Saturation of Alpha Particle Driven Instability in TFTR

Description: A nonlinear theory of kinetic instabilities near threshold [H.L. Berk, et al., Plasma Phys. Rep. 23, (1997) 842] is applied to calculate the saturation level of Toroidicity-induced Alfvén Eigenmodes (TAE) and be compared with the predictions of (delta)f method calculations [Y. Chen, Ph.D. Thesis, Princeton University, 1998]. Good agreement is observed between the predictions of both methods and the predicted saturation levels are comparable with experimentally measured amplitudes of the TAE oscillations in TFTR [D.J. Grove and D.M. Meade, Nucl. Fusion 25, (1985) 1167].
Date: September 15, 1998
Creator: Berk, H. L.; Chen, Y.; Gorelenkov, N. N. & White, R. B.

Two Methods for a First Order Hardware Gradiometer Using Two HTS SQUID's

Description: Two different systems for noise cancellation (first order gradiometers) have been developed using two similar high temperature superconducting (HTS) SQUIDs. ''Analog'' gradiometry is accomplished in hardware by either (1) subtracting the signals from the sensor and background SQUIDs at a summing amplifier (parallel technique) or (2) converting the inverted background SQUID signal to a magnetic field at the sensor SQUID (series technique). Balance levels achieved are 2000 and 1000 at 20 Hz for the parallel and series methods respectively. The balance level as a function of frequency is also presented. The effect which time delays in the two sets of SQUID electronics have on this balance level is presented and discussed.
Date: September 15, 1998
Creator: Espy, M.A.; Flynn, E.R.; Kraus, R.H., Jr. & Matlachov, A.