Search Results

open access

Alternative Fuels and Chemicals From Synthesis Gas Technical Progress Report: Number 23

Description: The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.
Date: June 30, 2000
Creator: Tijrn, Peter J.
Partner: UNT Libraries Government Documents Department
open access

Analysis, tuning and comparison of two general sparse solvers for distributed memory computers

Description: We describe the work performed in the context of a Franco-Berkeley funded project between NERSC-LBNL located in Berkeley (USA) and CERFACS-ENSEEIHT located in Toulouse (France). We discuss both the tuning and performance analysis of two distributed memory sparse solvers (superlu from Berkeley and mumps from Toulouse) on the 512 processor Cray T3E from NERSC (Lawrence Berkeley National Laboratory). This project gave us the opportunity to improve the algorithms and add new features to the codes. We then quite extensively analyze and compare the two approaches on a set of large problems from real applications. We further explain the main differences in the behavior of the approaches on artificial regular grid problems. As a conclusion to this activity report, we mention a set of parallel sparse solvers on which this type of study should be extended.
Date: June 30, 2000
Creator: Amestoy, P. R.; Duff, I. S.; L'Excellent, J. Y. & Li, X. S.
Partner: UNT Libraries Government Documents Department
open access

Aviation Safety: Safer Skies Initiative Has Taken Initial Steps to Reduce Accident Rates by 2007

Description: A chapter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the Federal Aviation Administration's (FAA) Safer Skies Initiative, focusing on: (1) to what extent addressing the safety problems to be addressed by the initiative will help reduce the fatal accident rate; (2) what progress the initiative has made in identifying and implementing interventions to address each of these safety problems; (3) what progress has been made in assessing the effectiveness of those interventions; and (4) how FAA is coordinating the Safer Skies initiative with other safety activities conducted throughout the agency, in partnership with the aviation industry, and by other federal agencies."
Date: June 30, 2000
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
open access

The Case for a 500 GEV E+E - Linear Collider

Description: There are now several proposals that have been put forward from around the world for an e{sup +}e{sup {minus}} linear collider with an initial center of mass energy of 500 GeV. In this paper, the authors discuss why a project of this type deserves priority as the next, major initiative in high energy physics.
Date: June 30, 2000
Creator: Bagger, J.; Baltay, C.; AL, ET; Marciano, W.; Paige, F.; Turcot, A. S. et al.
Partner: UNT Libraries Government Documents Department
open access

Combustion 2000

Description: This report presents work carried out under contract DE-AC22-95PC95144 ''Combustion 2000 - Phase II.'' The goals of the program are to develop a coal-fired high performance power generation system (HIPPS) that is capable of: {lg_bullet} thermal efficiency (HHV) {ge} 47% {lg_bullet} NOx, SOx, and particulates {le} 10% NSPS (New Source Performance Standard) {lg_bullet} coal providing {ge} 65% of heat input {lg_bullet} all solid wastes benign {lg_bullet} cost of electricity {le} 90% of present plants Phase I, which began in 1992, focused on the analysis of various configurations of indirectly fired cycles and on technical assessments of alternative plant subsystems and components, including performance requirements, developmental status, design options, complexity and reliability, and capital and operating costs. Phase I also included preliminary R&D and the preparation of designs for HIPPS commercial plants approximately 300 MWe in size. Phase II, had as its initial objective the development of a complete design base for the construction and operation of a HIPPS prototype plant to be constructed in Phase III. As part of a descoping initiative, the Phase III program has been eliminated and work related to the commercial plant design has been ended. The rescoped program retained a program of engineering research and development focusing on high temperature heat exchangers, e.g. HITAF development (Task 2); a rescoped Task 6 that is pertinent to Vision 21 objectives and focuses on advanced cycle analysis and optimization, integration of gas turbines into complex cycles, and repowering designs; and preparation of the Phase II Technical Report (Task 8). This rescoped program deleted all subsystem testing (Tasks 3, 4, and 5) and the development of a site specific engineering design and test plan for the HIPPS prototype plant (Task 7). Work reported herein is from: {lg_bullet} Task 2.2.4 Pilot Scale Testing {lg_bullet} Task 2.2.5.2 Laboratory and Bench Scale …
Date: June 30, 2000
Partner: UNT Libraries Government Documents Department
open access

Contingent Workers: Incomes and Benefits Lag Behind Those of Rest of Workforce

Description: A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on the status of contingent workers, focusing on the: (1) nature and size of the contingent workforce; (2) extent to which contingent workers have access to health insurance and pensions; (3) protections afforded these workers under laws regarding family and medical leave, retirement income, hourly wages, labor relations, civil rights, and health and safety; and (4) options available for providing contingent workers increased access to employee benefits and increased coverage under laws designed to protect workers."
Date: June 30, 2000
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
open access

Defense Inventory: Process for Canceling Inventory Orders Needs Improvement

Description: A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on the Department of Defense's (DOD) inventory management, focusing on the: (1) extent to which orders exceeded requirements when the orders were placed; and (2) processes for cancelling orders that exceeded requirements."
Date: June 30, 2000
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
open access

Department of Labor: Administering the Labor-Management Reporting and Disclosure Act

Description: A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the Labor-Management Reporting and Disclosure Act (LMRDA) of 1959, focusing on: (1) the Department of Labor's organizational structure and use of fiscal year (FY) 1999 resources to implement LMRDA; and (2) how the Department of Labor administers and enforces each title of the act for which it is responsible."
Date: June 30, 2000
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
open access

Department of Veterans Affairs: Credit Costs and Risks of Proposed VA Small Business Loan Guarantee Program

Description: A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO provided information on the federal costs and risks of a proposed program for the Department of Veterans Affairs (VA) to guarantee small business loans to veterans, focusing on: (1) the federal credit costs and risks of the proposed program; (2) the cost impact of alternative borrower requirements in the implementation of the proposed program; and (3) the administrative issues resulting from VA's implementation of the proposed program."
Date: June 30, 2000
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
open access

DISPOSAL CONTAINER HANDLING SYSTEM DESCRIPTION DOCUMENT

Description: The Disposal Container Handling System receives and prepares new disposal containers (DCs) and transfers them to the Assembly Transfer System (ATS) or Canister Transfer System (CTS) for loading. The system receives the loaded DCs from ATS or CTS and welds the lids. When the welds are accepted the DCs are termed waste packages (WPs). The system may stage the WP for later transfer or transfer the WP directly to the Waste Emplacement/Retrieval System. The system can also transfer DCs/WPs to/from the Waste Package Remediation System. The Disposal Container Handling System begins with new DC preparation, which includes installing collars, tilting the DC upright, and outfitting the container for the specific fuel it is to receive. DCs and their lids are staged in the receipt area for transfer to the needed location. When called for, a DC is put on a cart and sent through an airlock into a hot cell. From this point on, all processes are done remotely. The DC transfer operation moves the DC to the ATS or CTS for loading and then receives the DC for welding. The DC welding operation receives loaded DCs directly from the waste handling lines or from interim lag storage for welding of the lids. The welding operation includes mounting the DC on a turntable, removing lid seals, and installing and welding the inner and outer lids. After the weld process and non-destructive examination are successfully completed, the WP is either staged or transferred to a tilting station. At the tilting station, the WP is tilted horizontally onto a cart and the collars removed. The cart is taken through an air lock where the WP is lifted, surveyed, decontaminated if required, and then moved into the Waste Emplacement/Retrieval System. DCs that do not meet the welding non-destructive examination criteria are transferred to …
Date: June 30, 2000
Creator: Loros, E. F.
Partner: UNT Libraries Government Documents Department
open access

Engineering Development of Slurry Bubble Column Reactor (SBCR) Technology Quarterly Technical Progress Report: Number 21

Description: The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors.
Date: June 30, 2000
Creator: Toseland, Bernard A.
Partner: UNT Libraries Government Documents Department
open access

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
open access

Final Environmental Impact Statement for the JEA Circulating Fluidized Bed Combustor Project

Description: This EIS assesses environmental issues associated with constructing and demonstrating a project that would be cost-shared by DOE and JEA (formerly the Jacksonville Electric Authority) under the Clean Coal Technology Program. The project would demonstrate circulating fluidized bed (CFB) combustion technology at JEA's existing Northside Generating Station in Jacksonville, Florida, about 9 miles northeast of the downtown area of Jacksonville. The new CFB combustor would use coal and petroleum coke to generate nearly 300 MW of electricity by repowering the existing Unit 2 steam turbine, a 297.5-MW unit that has been out of service since 1983. The proposed project is expected to demonstrate emission levels of sulfur dioxide (SO{sub 2}), oxides of nitrogen (NO{sub x}), and particulate matter that would be lower than Clean Air Act limits while at the same time producing power more efficiently and at less cost than conventional coal utilization technologies. At their own risk, JEA has begun initial construction activities without DOE funding. Construction would take approximately two years and, consistent with the original JEA schedule, would be completed in December 2001. Demonstration of the proposed project would be conducted during a 2-year period from March 2002 until March 2004. In addition, JEA plans to repower the currently operating Unit 1 steam turbine about 6 to 12 months after the Unit 2 repowering without cost-shared funding from DOE. Although the proposed project consists of only the Unit 2 repowering, this EIS analyzes the Unit 1 repowering as a related action. The EIS also considers three reasonably foreseeable scenarios that could result from the no-action alternative in which DOE would not provide cost-shared funding for the proposed project. The proposed action, in which DOE would provide cost-shared finding for the proposed project, is DOE's preferred alternative. The EIS evaluates the principal environmental issues, including air quality, …
Date: June 30, 2000
Partner: UNT Libraries Government Documents Department
open access

Final Environmental Impact Statement for Treating Transuranic (TRU)/Alpha Low-level Waste at the Oak Ridge National Laboratory Oak Ridge, Tennessee

Description: The DOE proposes to construct, operate, and decontaminate/decommission a TRU Waste Treatment Facility in Oak Ridge, Tennessee. The four waste types that would be treated at the proposed facility would be remote-handled TRU mixed waste sludge, liquid low-level waste associated with the sludge, contact-handled TRU/alpha low-level waste solids, and remote-handled TRU/alpha low-level waste solids. The mixed waste sludge and some of the solid waste contain metals regulated under the Resource Conservation and Recovery Act and may be classified as mixed waste. This document analyzes the potential environmental impacts associated with five alternatives--No Action, the Low-Temperature Drying Alternative (Preferred Alternative), the Vitrification Alternative, the Cementation Alternative, and the Treatment and Waste Storage at Oak Ridge National Laboratory (ORNL) Alternative.
Date: June 30, 2000
Partner: UNT Libraries Government Documents Department
open access

Final report to the Department of Energy, Basic Energy Sciences, Grant No. DE-FG02-97ER45649 [Theoretical study of phonon modes and electron-phonon scattering]

Description: We have studied the effect of additional layering within a semiconductor quantum well on carrier mobility compared to a simple quantum well. The previous report indicated results concerning modification of the phonon dispersion of the quantum well with additional layering and enhanced scattering from interface phonons accompanied by a reduction in confined phonon scattering. New results for this report are calculated relaxation times for transitions into all subbands of the quantum well structures and subsequent mobilities. We have found that mobilities are enhanced in structurally modified quantum well systems compared to simple quantum wells. Structurally modified quantum wells have additional thin layers of barrier material inside the well regions. For the case considered here, we have studied GaAs/AlAs quantum wells with thin AlAs layers, 8 {angstrom} in width, at room temperature. We have found that structurally modified quantum wells in the approximate ranges of 50-90 {angstrom}, 200-250 {angstrom}, and 370-400 {angstrom} show higher mobilities when compared to simple quantum wells of comparable widths. Mobilities increase when the separation between subbands is unfavorable for single phonon emission or absorption. Upon reaching resonance there is a sharp decrease in the mobilities until conditions become favorable again. This is a final report on the theoretical study of phonon modes and electron-phonon scattering in structurally modified electronic materials.
Date: June 30, 2000
Creator: McIntyre, Dr. Cynthia R.
Partner: UNT Libraries Government Documents Department
open access

Hydropower Relicensing: Federal Costs Are Not Being Recovered

Description: A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed hydropower relicensing, focusing on the status of efforts to recover the costs incurred by federal agencies to administer the hydropower program."
Date: June 30, 2000
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
open access

Information Policy: NTIS' Financial Position Provides an Opportunity to Reassess Its Mission

Description: A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO reviewed the National Technical Information Service's (NTIS) financial position, focusing on whether: (1) NTIS can continue to be self-sufficient and, if not, what issues need to be addressed; and (2) NTIS' World News Connection's (WNC) online foreign news service exceeds NTIS' statutory authority to the detriment of private firms offering similar news services."
Date: June 30, 2000
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
open access

INTEGRATED SYSTEM TO CONTROL PRIMARY PM 2.5 FROM ELECTRIC POWER PLANTS

Description: Task 1 involves fitting the conventional ElectroCore separator with a central electrode and evaluating the performance. The conventional ElectroCore, used in the field test at Plant Miller near Birmingham, Alabama, was shipped to the LSR laboratory where it was cleaned and inspected. The unit had been sitting unprotected outdoors and was badly rusted inside and out. After cleaning the unit to the best of our ability, the internal walls of the separator were still very rough compared to when the unit was new. Restoring the unit to its original condition was estimated to cost about $30,000 and take about 16 weeks, so it was decided to modify the test procedures to be able to use the unit in its existing condition. Repairing the unit would put the project over budget and behind schedule. The rough walls would have little impact on the electrical characteristics or on the details of the flow geometry. It was believed that the rough walls would have a large impact on particle performance because the particles are expected to bounce along the wall before being extracted from the bleed flow outlet slot. The device is designed to prevent particles from adhering to the walls and it would be impossible to keep particles from adhering to the now roughened surface. The approach was to use the unit for evaluating the central electrode installation and to look at the gas flows within the unit but not to use it to measure particle separation efficiency.
Date: June 30, 2000
Partner: UNT Libraries Government Documents Department
open access

Intelligent Machine Learning Analysis for Fuel Cell Operations

Description: A performance computational model for a 100 kW nominal solid oxide fuel cell generator system is described. The calculational methods are based on the FORTRAN programming language. Comprehensive parameter input options are presented, and constraints are identified. Example reactant, electrical, and efficiency outputs are demonstrated over the relevant operating ranges. A sample calculated output display at nominal operating conditions is given.
Date: June 30, 2000
Creator: Murphy, R. W. & Hoyt, W. A.
Partner: UNT Libraries Government Documents Department
open access

Monitoring the Durability Performance of Concrete in Nuclear Waste Containment. Technical Progress Report No. 4

Description: OAK-B135 Monitoring the Durability Performance of Concrete in Nuclear Waste Containment. Technical Progress Report No. 4. The analysis of the effect of cracks on the acceleration of the calcium leaching process of cement-based materials has been pursued. During the last period (Technical Progress Report No 3), we have introduced a modeling accounting for the high diffusivity of fractures in comparison with the weak solid material diffusivity. It has been shown through dimensional and asymptotic analysis that small fractures do not significantly accelerate the material aging process. This important result for the overall structural aging kinetics of containment structure has been developed in a paper submitted to the international journal ''Transport in Porous Media''.
Date: June 30, 2000
Creator: Ulm, Franz-Josef
Partner: UNT Libraries Government Documents Department
Back to Top of Screen