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Modelos de Simulación a Diferentes Escalas de la Dinámica del Bosque Tropical. Reserva Forestal Imataca. Sector Central.

Description: Thesis submitted to the National Experimental University of Guayana as partial requirement for the degree of Master of Science in Environmental Science. This thesis discusses simulation models at different scales of tropical forest dynamics.
Date: June 2000
Creator: Delgado, Luz A. & Acevedo, Miguel F.
Partner: UNT College of Engineering

STI. DE-FG02-00ER1505 [Brief summary of 11th International Conference on Arabidopsis Research]

Description: The 11th International Conference on Arabidopsis Research was held in Madison, Wisconsin, June 24 through June 28, 2000. Arabidopsis thaliana has been the subject of genetic study for many years. However, during the last decade, the number of research laboratories using Arabidopsis as a model system has increased tremendously, and Arabidopsis is currently being used to study all aspects of plant biology. The rapid rate of progress in Arabidopsis research, including the completion of the genomic sequence, underscores the usefulness of holding a meeting every year. These conferences provide an important opportunity for the Arabidopsis community to interact and exchange information. The meeting opened with an evening keynote address on the global impact of plant biology, delivered by Richard Jefferson, the Executive Director of CAMBIA (Center for the Application of Molecular Biology to International Agriculture). This was followed by short updates from each of the NSF-funded Plant Genome groups. Many of these groups are carrying out projects that impact the Arabidopsis community. Each of the 17 platform sessions consisted of talks from two invited speakers followed by two short talks that were chosen from the submitted poster abstracts. A concerted effort was made to invite junior investigators, including graduate students and postdocs, to give these talks. Posters were available for viewing during three formal sessions, and, because the poster session was adjacent to the lecture hall, it was easy for participants to go back and forth between posters and lectures. Finally, a mixer and an informal banquet provided opportunities for participants to meet new people and renew acquaintances. Furthermore, the registration package included all lunches and dinners together in a cafeteria next to the posters and lecture hall, thus encouraging the meeting of established investigators with students and postdocs. The North American Arabidopsis Steering Committee (elected by electronic ballot by ...
Date: June 24, 2000
Partner: UNT Libraries Government Documents Department

Entanglement and Quantum Computation: An Overview

Description: This report presents a selective compilation of basic facts from the fields of particle entanglement and quantum information processing prepared for those non-experts in these fields that may have interest in an area of physics showing counterintuitive, ''spooky'' (Einstein's words) behavior. In fact, quantum information processing could, in the near future, provide a new technology to sustain the benefits to the U.S. economy due to advanced computer technology.
Date: June 27, 2000
Creator: Perez, R.B.
Partner: UNT Libraries Government Documents Department

Dynamics of Coupled Contaminant and Microbial Transport in Heterogeneous Porous Media: Purdue Component

Description: Dynamic microbial attachment/detachment occurs in subsurface systems in response to changing environmental conditions caused by contaminant movement and degradation. Understanding the environmental conditions and mechanisms by which anaerobic bacteria partition between aqueous and solid phases is a critical requirement for designing and evaluating in situ bioremediation efforts. This interdisciplinary research project, of which we report only the Purdue contribution, provides fundamental information on the attachment/detachment dynamics of bacteria in heterogeneous porous media. Fundamental results from the Purdue collaboration are: (a) development of a matched-index method for obtaining 3-D Lagrangian trajectories of microbial sized particles transporting within porous media or microflow cells, (b) application of advanced numerical methods to optimally design a microflow cell for studying anaerobic bacterial attachment/detachment phenomena, (c) development of two types of models for simulating bacterial movement and attachment/detachment in microflow cells and natural porous media, (d) application of stochastic analysis to upscale pore scale microbial attachment/detachment models to natural heterogeneous porous media, and (e) evaluation of the role nonlocality plays in microbial dynamics in heterogeneous porous media
Date: June 1, 2000
Creator: Cushman, J.H. & Fletcher, Madilyn
Partner: UNT Libraries Government Documents Department

Effect of Extrusion Temperature on the Microstructural Development of Powder Metallurgy Ti-47A1-2Cr-1Nb-1Ta Alloy

Description: Effect of extrusion temperatures on the microstructural development of a powder metallurgy (PM) Ti-47Al-2Cr-1Nb-1Ta (at. %) alloy has been investigated. Microstructure of the PM alloy extruded at 1150 C consists of a fine-grained ({gamma} + {alpha}{sub 2}) two-phase structure in association with coarse grains of metastable B2 (ordered bcc) phase. In addition, fine {omega} (ordered hexagonal) particles are also found within some B2 grains. The PM alloy containing the metastable B2 grains displays a low-temperature superplastic behavior, in which a tensile elongation of 310% is obtained at 800 C under a strain rate of 2 x 10{sup -5} s{sup -1}. It is suggested that the decomposition of metastable B2 phase and microstructural evolution during the deformation play a crucial role in the low-temperature superplasticity of the PM TiAl alloy. A refined fully-lamellar (FL) microstructure with alternating {gamma} and {alpha}{sub 2} lamellae is developed within the PM alloy extruded at 1400 C. The creep resistance of the refined FL-TiAl alloy is found to be superior to those of the TiAl alloys fabricated by conventional processing techniques. Creep mechanisms for the PM alloy with a refined FL microstructure are critically discussed according to TEM examination of deformation substructure.
Date: June 29, 2000
Creator: Hsiung, L. & Nieh, T.G.
Partner: UNT Libraries Government Documents Department

Enhancements in Magnesium Die Casting Impact Properties

Description: The need to produce lighter components in transportation equipment is the main driver in the increasing demand for magnesium castings. In many automotive applications, components can be made of magnesium or aluminum. While being lighter, often times the magnesium parts have lower impact and fatigue properties than the aluminum. The main objective of this study was to identify potential improvements in the impact resistance of magnesium alloys. The most common magnesium alloys in automotive applications are AZ91D, AM50 and AM60. Accordingly, these alloys were selected as the main candidates for the study. Experimental quantities of these alloys were melted in an electrical furnace under a protective atmosphere comprising sulfur hexafluoride, carbon dioxide and dry air. The alloys were cast both in a permanent mold and in a UBE 315 Ton squeeze caster. Extensive evaluation of tensile, impact and fatigue properties was conducted at CWRU on permanent mold and squeeze cast test bars of AZ91, AM60 and AM50. Ultimate tensile strength values between 20ksi and 30ksi were obtained. The respective elongations varied between 25 and 115. the Charpy V-notch impact strength varied between 1.6 ft-lb and 5 ft-lb depending on the alloy and processing conditions. Preliminary bending fatigue evaluation indicates a fatigue limit of 11-12 ksi for AM50 and AM60. This is about 0.4 of the UTS, typical for these alloys. The microstructures of the cast specimens were investigated with optical and scanning electron microscopy. Concomitantly, a study of the fracture toughness in AM60 was conducted at ORNL as part of the study. The results are in line with values published in the literature and are representative of current state of the art in casting magnesium alloys. The experimental results confirm the strong relationship between aluminum content of the alloys and the mechanical properties, in particular the impact strength and the ...
Date: June 30, 2000
Creator: Schwam, David; Wallace, John F.; Zhu, Yulong; Viswanathan, Srinath & Iskander, Shafik
Partner: UNT Libraries Government Documents Department

Oak Ridge National Laboratory Facilities Revitalization Project - Project Management Plan

Description: The Facilities Revitalization Project (FRP) has been established at Oak Ridge National Laboratory (ORNL) to provide new and/or refurbished research and support facilities for the Laboratory's science mission. The FRP vision is to provide ORNL staff with world-class facilities, consolidated at the X-10 site, with the first phase of construction to be completed within five years. The project will utilize a combination of U.S. Department of Energy (DOE), State of Tennessee, and private-sector funds to accomplish the new construction, with the facilities requirements to be focused on support of the ORNL Institutional Plan. This FRP Project Management Plan has been developed to provide the framework under which the project will be conducted. It is intended that the FRP will be managed as a programmatic office, with primary resources for execution of the project to be obtained from the responsible organizations within ORNL (Engineering, Procurement, Strategic Planning, etc.). The FRP Project Management Plan includes a definition of the project scope, the organizational responsibilities, and project approach, including detailed Work Breakdown Structure (WBS), followed by more detailed discussions of each of the main WBS elements: Project Planning Basis, Facility Deactivation and Consolidation, and New Facilities Development. Finally, a general discussion of the overall project schedule and cost tracking approach is provided.
Date: June 6, 2000
Creator: Myrick, T.E.
Partner: UNT Libraries Government Documents Department

ALARA Design Review for the Resumption of the Plutonium Finishing Plant (PFP) Cementation Process Project Activities

Description: The requirements for the performance of radiological design reviews are codified in 10CFR835, Occupational Radiation Protection. The basic requirements for the performance of ALARA design reviews are presented in the Hanford Site Radiological Control Manual (HSRCM). The HSRCM has established trigger levels requiring radiological reviews of non-routine or complex work activities. These requirements are implemented in site procedures HNF-PRO-1622 and 1623. HNF-PRO-1622 Radiological Design Review Process requires that ''radiological design reviews [be performed] of new facilities and equipment and modifications of existing facilities and equipment''. In addition, HNF-PRO-1623 Radiological Work Planning Process requires a formal ALARA Review for planned activities that are estimated to exceed 1 person-rem total Dose Equivalent (DE). The purpose of this review is to validate that the original design for the PFP Cementation Process ensures that the principles of ALARA (As Low As Reasonably Achievable) were included in the original project design. That is, that the design and operation of existing Cementation Process equipment and processes allows for the minimization of personnel exposure in its operation, maintenance and decommissioning and that the generation of radioactive waste is kept to a minimum.
Date: June 14, 2000
Creator: DAYLEY, L.
Partner: UNT Libraries Government Documents Department

Parametric Analyses of Heat Removal from High Level Waste Tanks

Description: The general thermal hydraulics program GOTH-SNF was used to predict the thermal response of the waste in tanks 241-AY-102 and 241-AZ-102 when mixed by two 300 horsepower mixer pumps. This mixing was defined in terms of a specific waste retrieval scenario. Both dome and annulus ventilation system flow are necessary to maintain the waste within temperature control limits during the mixing operation and later during the sludge-settling portion of the scenario are defined.
Date: June 5, 2000
Creator: TRUITT, J.B.
Partner: UNT Libraries Government Documents Department

Strong Earthquake Motion Estimates for the UCSB Campus, and Related Response of the Engineering 1 Building

Description: This is the second report on the UC/CLC Campus Earthquake Program (CEP), concerning the estimation of exposure of the U.C. Santa Barbara campus to strong earthquake motions (Phase 2 study). The main results of Phase 1 are summarized in the current report. This document describes the studies which resulted in site-specific strong motion estimates for the Engineering I site, and discusses the potential impact of these motions on the building. The main elements of Phase 2 are: (1) determining that a M 6.8 earthquake on the North Channel-Pitas Point (NCPP) fault is the largest threat to the campus. Its recurrence interval is estimated at 350 to 525 years; (2) recording earthquakes from that fault on March 23, 1998 (M 3.2) and May 14, 1999 (M 3.2) at the new UCSB seismic station; (3) using these recordings as empirical Green's functions (EGF) in scenario earthquake simulations which provided strong motion estimates (seismic syntheses) at a depth of 74 m under the Engineering I site; 240 such simulations were performed, each with the same seismic moment, but giving a broad range of motions that were analyzed for their mean and standard deviation; (4) laboratory testing, at U.C. Berkeley and U.C. Los Angeles, of soil samples obtained from drilling at the UCSB station site, to determine their response to earthquake-type loading; (5) performing nonlinear soil dynamic calculations, using the soil properties determined in-situ and in the laboratory, to calculate the surface strong motions resulting from the seismic syntheses at depth; (6) comparing these CEP-generated strong motion estimates to acceleration spectra based on the application of state-of-practice methods - the IBC 2000 code, UBC 97 code and Probabilistic Seismic Hazard Analysis (PSHA), this comparison will be used to formulate design-basis spectra for future buildings and retrofits at UCSB; and (7) comparing the response of ...
Date: June 6, 2000
Creator: Archuleta, R.; Bonilla, F.; Doroudian, M.; Elgamal, A. & Hueze, F.
Partner: UNT Libraries Government Documents Department

Analysis for Eccentric Multi Canister Overpack (MCO) Drops at the Canister Storage Building (CSB) (CSB-S-0073)

Description: The purpose of this report is to investigate the potential for damage to the multi-canister overpack (MCO) during impact from an eccentric accidental drop onto the standard storage tube, overpack storage tube, service station or sampling/weld station. Damage to the storage tube and sample/weld station is beyond the scope of this report. The results of this analysis are required to show the following: (1) If a breach resulting in unacceptable release of contamination could occur in the MCO. (2) If the dropped MCO could become stuck in the storage tube after the drop. (3) Maximum deceleration of the spent nuclear fuel baskets. The model appropriate for the standard storage tubes with the smaller gap is the basis for the analysis and results reported herein in this SNF-5204, revision 2 report. Revision 1 of this report is based on a model that includes the larger gap appropriate for the overpack tubes.
Date: June 7, 2000
Partner: UNT Libraries Government Documents Department

Project Execution Plan Project 98L-EWW-460 Plutonium Stabilization and Handling DOE 98-D-453

Description: This Project Execution Plan (PEP) describes the management methods and responsibilities of the project participants. Project W-460 is sufficiently large to warrant a stand alone PEP. This project specific PEP describes the relationships and responsibilities of the project team and identifies the technical, schedule, and cost baselines that have been established for the project. The Department of Energy (DOE), Hanford Works (Hanford), at Richland, Wa. currently does not have a system capable of stabilizing or packaging large quantities of plutonium-bearing solids to meet DOE technical standard DOE-STD-3013-99. This project will allow Hanford to meet this standard by installing stabilization and packaging equipment (SPE). The SPE is capable of stabilizing and packaging the current inventory of greater than 30 percent plutonium-bearing materials currently stored in the Plutonium Finishing Plant's (PFP) vaults into 3013 storage containers. The scope of this project is to procure and install the SPE via a Hanford contract and coordination with the Savannah River Site. In addition, the project will modify PFP vaults and upgrade the PFP Laboratory measurement systems. The Facility infrastructure will be modified to support the new SPE system and the new standardized storage container configuration.
Date: June 21, 2000
Creator: MCGRATH, G.M.
Partner: UNT Libraries Government Documents Department

Technical Issues and Characterization for Fuel and Sludge in Hanford K Basins

Description: Technical Issues for the interim dry storage of N Reactor Spent Nuclear Fuel (SNF) are discussed. Characterization data from fuel, to support resolution of these issues, are reviewed and new results for the oxidation of fuel in a moist atmosphere and the drying of whole fuel elements are presented. Characterization of associated K basin sludge is also discussed in light of a newly adopted disposal pathway.
Date: June 1, 2000
Creator: MAKENAS, B.J.
Partner: UNT Libraries Government Documents Department

Mass Spectrometric Immunoassay for Parathyroid Hormone Related Protein (PTHrP)

Description: Many cancers, including prostate, breast and lung express parathyroid hormone related protein (PTHrP). Despite the common tumor overexpression of PTHrP, serum levels of PTHrP are not commonly elevated in affected patients. They postulate that the reasons for the discrepancy between tissue and serum measurements of PTHrP are the inadequate sensitivity and specificity of current PTHrP serum assays. To improve the clinical value of PTHrP serum assays for the cancer patient, they are developing a new generation of novel and ultrasensitive PTHrP serum immunoassays based on immunoaffinity purification, nanospray liquid chromatography tandem mass spectrometry (LC/MS/MS) and accelerator mass spectrometry (AMS).
Date: June 16, 2000
Creator: Zheng, K.; Rivera, J.D.; Vogel, J.S.; Buchholz, B.A.; Burton, D.W.; Deftos, L.J. et al.
Partner: UNT Libraries Government Documents Department

American National Standard ANSI/ANS-8.12-1987: Criticality Control of Plutonium-Uranium Mixtures

Description: American National Standard ANSI/ANS-8.12-1987 (Ref. 1) was approved for use on September 11, 1987, The history of the development of the standard is discussed in Ref. 2. The first version of this standard, which included subcritical limits only on homogeneous plutonium-uranium fuel mixtures, was approved July 17, 1978. The current version was revised to add limits on heterogeneous systems (Ref., 3). This paper provides additional information on the limits presented in the standard.
Date: June 13, 2000
Creator: Shaeffer, M.K. & Keeton, S.C.
Partner: UNT Libraries Government Documents Department

Artificial Neural Network Solutions of Slab-Geometry Neutron Diffusion Problems

Description: Artificial neural network (ANN) methods have been researched extensively within the nuclear community for applications in systems control, diagnostics, and signal processing. We consider here the use of multilayer perceptron ANNs as an alternative to finite-difference and finite-element methods for obtaining solutions to neutron diffusion problems. This work is based on a method proposed by van Milligen et. al. to obtain solutions of the differential equations arising in plasma physics applications. This ANN method has the potential advantage of yielding an accurate, differentiable approximation to the solution of diffusion problems at all points in the spatial domain.
Date: June 12, 2000
Creator: Brantley, P. S.
Partner: UNT Libraries Government Documents Department

A Study of the Effects of Disorder in the 2D Hubbard Model

Description: We study the effects of disorder on long range antiferromagnetic correlations and the Mott gap in the half-filled, two dimensional, repulsive Hubbard model. We employ Hartree-Fock (HF) and Quantum Monte Carlo (QMC) techniques in our study of the bond and site disordered models. Results from mean field (HF) calculations are used to develop a qualitative picture of the physics and to guide our choice for input to the QMC methods. The basic properties of two QMC methods for correlated fermions are discussed, and the results from these different approaches are presented.
Date: June 5, 2000
Creator: Enjalran, M.; Hebert, F.; Scalettar, R.; Zhang, S. & Batrouni, G.
Partner: UNT Libraries Government Documents Department

Calibration Facilities for NIF

Description: The calibration facilities will be dynamic and will change to meet the needs of experiments. Small sources, such as the Manson Source should be available to everyone at any time. Carrying out experiments at Omega is providing ample opportunity for practice in pre-shot preparation. Hopefully, the needs that are demonstrated in these experiments will assure the development of (or keep in service) facilities at each of the laboratories that will be essential for in-house preparation for experiments at NIF.
Date: June 15, 2000
Creator: Perry, T. S.
Partner: UNT Libraries Government Documents Department

Non-Inductive Current Drive Modeling Extending Advanced Tokamak Operation to Steady State

Description: A critical issue for sustaining high performance, negative central shear (NCS) discharges is the ability to maintain current distributions that are maximum off axis. Sustaining such hollow current profiles in steady state requires the use of non-inductively driven current sources. On the DIII-D experiment, a combination of neutral beam current drive (NBCD) and bootstrap current have been used to create transient NCS discharges. The electron cyclotron heating (ECH) and current drive (ECCD) system is currently being upgraded from three gyrotrons to six to provide more than 3MW of absorbed power in long-pulse operation to help sustain the required off-axis current drive. This upgrade SuPporrs the long range goal of DIII-D to sustain high performance discharges with high values of normalized {beta}, {beta}{sub n} = {beta}/(I{sub p}/aB{sub T}), confinement enhancement factor, H, and neutron production rates while utilizing bootstrap current fraction, f{sub bs}, in excess of 50%. At these high performance levels, the likelihood of onset of MHD modes that spoil confinement indicates the need to control plasma profiles if we are to extend this operation to long pulse or steady state. To investigate the effectiveness of the EC system and to explore operating scenarios to sustain these discharges, we use time-dependent simulations of the equilibrium, transport and stability. We explore methods to directly alter the safety factor profile, q, through direct current drive or by localized electron heating to modify the bootstrap current profile. Time dependent simulations using both experimentally determined [1] and theory-based [2] energy transport models have been done. Here, we report on simulations exploring parametric dependencies of the heating, current drive, and profiles that affect our ability to sustain stable discharges.
Date: June 6, 2000
Creator: Casper, T.A.; Lodestro, L.L.; Pearlstein, L.D.; Porter, G.D.; Murakami, M.; Lao, L.L. et al.
Partner: UNT Libraries Government Documents Department

Composite Thin-Disk Laser Scaleable to 100 kW Average Power Output and Beyond

Description: By combining newly developed technologies to engineer composite laser components with state of the art diode laser pump delivery technologies, we are in a position to demonstrate high beam quality, continuous wave, laser radiation at scaleable high average powers. The crucial issues of our composite thin disk laser technology were demonstrated during a successful first light effort. The high continuous wave power levels that are now within reach make this system of high interest to future DoD initiatives in solid-state laser technology for the laser weapon arena.
Date: June 1, 2000
Creator: Zapata, L.; Beach, R. & Payne, S.
Partner: UNT Libraries Government Documents Department

Tank Monitoring and Control System (TMACS) Acceptance Test Procedure

Description: The purpose of this document is to describe tests performed to validate Revision 12.0 of the TMACS Monitor and Control System (TMACS) and verify that the software functions as intended by design. This document is intended to test the software portion of TMACS. The tests will be performed on the development system. The software to be tested is the TMACS knowledge bases (KB) and the I/O driver/services. The development system will not be communicating to field equipment; instead, the field equipment is simulated using emulators or multiplexers in the lab.
Date: June 1, 2000
Creator: BARNES, D.A.
Partner: UNT Libraries Government Documents Department

Training implementation matrix, Spent Nuclear Fuel Project (SNFP)

Description: This Training Implementation Matrix (TIM) describes how the Spent Nuclear Fuel Project (SNFP) implements the requirements of DOE Order 5480.20A, Personnel Selection, Qualification, and Training Requirements for Reactor and Non-Reactor Nuclear Facilities. The TIM defines the application of the selection, qualification, and training requirements in DOE Order 5480.20A at the SNFP. The TIM also describes the organization, planning, and administration of the SNFP training and qualification program(s) for which DOE Order 5480.20A applies. Also included is suitable justification for exceptions taken to any requirements contained in DOE Order 5480.20A. The goal of the SNFP training and qualification program is to ensure employees are capable of performing their jobs safely and efficiently.
Date: June 8, 2000
Creator: EATON, G.L.
Partner: UNT Libraries Government Documents Department

Canister Cleaning System Final Design Report Project A-2A

Description: Approximately 2,300 metric tons Spent Nuclear Fuel (SNF) are currently stored within two water filled pools, the 105 K East (KE) fuel storage basin and the 105 K West (KW) fuel storage basin, at the U.S. Department of Energy, Richland Operations Office (RL). The SNF Project is responsible for operation of the K Basins and for the materials within them. A subproject to the SNF Project is the Debris Removal Subproject, which is responsible for removal of empty canisters and lids from the basins. The Canister Cleaning System (CCS) is part of the Debris Removal Project. The CCS will be installed in the KW Basin and operated during the fuel removal activity. The KW Basin has approximately 3600 canisters that require removal from the basin. The CCS is being designed to ''clean'' empty fuel canisters and lids and package them for disposal to the Environmental Restoration Disposal Facility complex. The system will interface with the KW Basin and be located in the Dummy Elevator Pit.
Date: June 15, 2000
Creator: FARWICK, C.C.
Partner: UNT Libraries Government Documents Department