Berkeley Lab's ALS generates Femtosecond Synchrotron Radiation (open access)

Berkeley Lab's ALS generates Femtosecond Synchrotron Radiation

A Lawrence Berkeley National Laboratory (Berkeley Lab) team drawing its members from the Materials Sciences Division (MSD), the Center for Beam Physics in the Accelerator and Fusion Research Division, and the Advanced Light Source (ALS) has succeeded in generating 300-femtosecond pulses of synchrotron radiation at the ALS synchrotron radiation machine. Though this ''proof-of-principle'' experiment made use of visible light on a borrowed beamline, the laser ''time-slicing'' technique at the heart of the demonstration will soon be applied in a new bend-magnet beamline designed explicitly for the production of femtosecond pulses of X-rays to study long-range and local order in condensed matter with ultrafast time resolution. An undulator beamline based on the same technique has been proposed that will dramatically increase the flux and brightness.
Date: May 23, 2000
Creator: Robinson, Arthur L.
Object Type: Article
System: The UNT Digital Library
Biofuels for sustainable transportation (open access)

Biofuels for sustainable transportation

Biomass is an attractive energy source, and transportation fuels made from biomass offer a number of benefits. Developing the technology to produce and use biofuels will create transportation fuel options that can positively impact the national energy security, the economy, and the environment. Biofuels include ethanol, methanol, biodiesel, biocrude, and methane.
Date: May 23, 2000
Creator: Neufeld, S.
Object Type: Book
System: The UNT Digital Library
Clean Water Act Reauthorization (open access)

Clean Water Act Reauthorization

None
Date: May 23, 2000
Creator: Copeland, Claudia
Object Type: Report
System: The UNT Digital Library
Combined macro-meso scale modeling of sintering. Part I: Continuum approach (open access)

Combined macro-meso scale modeling of sintering. Part I: Continuum approach

An integrated approach, including a continuum theory of sintering and mesostructure evolution analysis, is used for the solution of the problem of bi-layered structure sintering. Two types of bi-layered structures are considered: layers of the same material different by initial porosity, and layers of two different materials. The effective sintering stress and the normalized bulk modulus for the bi-layer powder sintering are derived based on mesoscale simulations. The combined effect of the layers' porosity and differences in sintering rate on shrinkage and warpage is studied for both sintering on a rigid substrate and free sintering.
Date: May 23, 2000
Creator: OLEVSKY,EUGENE A. & TIKARE,VEENA
Object Type: Article
System: The UNT Digital Library
Combined macro-meso scale modeling of sintering. Part II, Mesoscale simulations (open access)

Combined macro-meso scale modeling of sintering. Part II, Mesoscale simulations

A mesoscale kinetic Monte Carlo model is presented to simulate microstructural evolution during sintering of 2D complex microstructures which evolves by grain growth, pore migration and densification. No assumptions about the geometry of the evolving microstructure are made. The results of these simulations are used to generate sintering stress and normalize viscous bulk modulus for use in continuum level simulation of sintering. The advantage of these simulations is that they can be used to generate more accurate parameters as various assumptions regarding geometry and transport mechanism are made. The previous companion paper used the results from the mesoscale simulations to simulate shrinkage and warpage in sintering of bilayer ceramics.
Date: May 23, 2000
Creator: TIKARE,VEENA; OLEVSKY,EUGENE A. & BRAGINSKY,MICHAEL V.
Object Type: Article
System: The UNT Digital Library
Commodity multi-processor systems in the ATLAS level-2 trigger (open access)

Commodity multi-processor systems in the ATLAS level-2 trigger

Low cost SMP (Symmetric Multi-Processor) systems provide substantial CPU and I/O capacity. These features together with the ease of system integration make them an attractive and cost effective solution for a number of real-time applications in event selection. In ATLAS the authors consider them as intelligent input buffers (active ROB complex), as event flow supervisors or as powerful processing nodes. Measurements of the performance of one off-the-shelf commercial 4-processor PC with two PCI buses, equipped with commercial FPGA based data source cards (microEnable) and running commercial software are presented and mapped on such applications together with a long-term program of work. The SMP systems may be considered as an important building block in future data acquisition systems.
Date: May 23, 2000
Creator: Abolins, M.; Blair, R.; Bock, R.; Bogaerts, A.; Dawson, J.; Ermoline, Y. et al.
Object Type: Article
System: The UNT Digital Library
Computational environment and software configuration management of the 1996 performance assessment for the Waste Isolation Pilot Plant (open access)

Computational environment and software configuration management of the 1996 performance assessment for the Waste Isolation Pilot Plant

The US Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP), located in southeast New Mexico, is a deep geologic repository for the permanent disposal of transuranic waste generated by DOE defense-related activities. Sandia National Laboratories (SNL), in its role as scientific advisor to the DOE, is responsible for evaluating the long-term performance of the WIPP. This risk-based Performance Assessment (PA) is accomplished in part through the use of numerous scientific modeling codes, which rely for some of their inputs on data gathered during characterization of the site. The PA is subject to formal requirements set forth in federal regulations. In particular, the components of the calculation fall under the configuration management and software quality assurance aegis of the American Society of Mechanical Engineers (ASME) Nuclear Quality Assurance (NQA) requirements. This paper describes SNL's implementation of the NQA requirements regarding configuration management. The complexity of the PA calculation is described, and the rationale for developing a flexible, robust run-control process is discussed. The run-control implementation is described, and its integration with the configuration-management system is then explained, to show how a calculation requiring 37,000 CPU-hours, and involving 225,000 output files totaling 95 Gigabytes, was accomplished in 5 months by 2 …
Date: May 23, 2000
Creator: Froehlich, Gary K.; Williamson, Charles M. & Ogden, Harvey C.
Object Type: Article
System: The UNT Digital Library
Conservation Reserve Program: Status and Current Issues (open access)

Conservation Reserve Program: Status and Current Issues

The Conservation Reserve Program (CRP), enacted in 1985, enables producers to retire highly erodible or environmentally sensitive cropland, usually for 10 years. Congress reauthorized and amended the CRP in the 1996 Federal Agriculture Improvement and Reform Act (P.L. 104-127; 16 U.S.C. 3811, et seq.). The law caps enrollment at 36.4 million acres and makes funding mandatory through the commodity Credit Corporation.
Date: May 23, 2000
Creator: Zinn, Jeffrey A.
Object Type: Report
System: The UNT Digital Library
Engineering Task Plan for the Integrity Assessment Examination of Double Contained Receiver Tanks (DCRT) Catch Tanks and Ancillary facilities (open access)

Engineering Task Plan for the Integrity Assessment Examination of Double Contained Receiver Tanks (DCRT) Catch Tanks and Ancillary facilities

This Engineering Task Plan (ETP) presents the integrity assessment examination of three DCRTs, seven catch tanks, and two ancillary facilities located in the 200 East and West Areas of the Hanford Site. The integrity assessment examinations, as described in this ETP, will provide the necessary information to enable the independently qualified registered professional engineer (IQRPE) to assess the condition and integrity of these facilities. The plan is consistent with the Double-Shell Tank Waste Transfer Facilities Integrity Assessment Plan.
Date: May 23, 2000
Creator: Becker, D. L.
Object Type: Report
System: The UNT Digital Library
Evaluation of electric vehicle production and operating costs (open access)

Evaluation of electric vehicle production and operating costs

This report presents an analysis of the initial cost of electric vehicles (EVs). The manufacturing and retail cost structure of mature conventional vehicles produced at high volume is analyzed first, and the contributions by various cost categories to vehicle price are estimated. The costs are then allocated to such vehicle component groups as body, chassis, and powertrain. The similarities and differences among various component systems are reviewed. In electric vehicles, an electric drive replaces the conventional powertrain, and a battery pack replaces the fuel system. Three types of traction motors are reviewed, and their cost in high-volume production is analyzed. Various components of the motor and controller package are analyzed, and their representative costs are summarized. Four types of EV batteries are reviewed, and their costs are presented. Various alternatives for the low-, medium-, and high-volume production of EVs are evaluated, and some sample costs are presented. A methodology that estimates initial and operating costs on the basis of this analysis is presented. The methodology also estimates the average lifetime cost of owning and operating an electric vehicle.
Date: May 23, 2000
Creator: Cuenca, R. M.; Gaines, L. L. & Vyas, A. D.
Object Type: Report
System: The UNT Digital Library
Exploratory Technology Research Program for Electrochemical Energy Storage, Annual Report for 1999 (open access)

Exploratory Technology Research Program for Electrochemical Energy Storage, Annual Report for 1999

None
Date: May 23, 2000
Creator: Kinoshita, K.
Object Type: Report
System: The UNT Digital Library
FY96-98 Summary Report Mercury: Next Generation Laser for High Energy Density Physics SI-014 (open access)

FY96-98 Summary Report Mercury: Next Generation Laser for High Energy Density Physics SI-014

The scope of the Mercury Laser project encompasses the research, development, and engineering required to build a new generation of diode-pumped solid-state lasers for Inertial Confinement Fusion (ICF). The Mercury Laser will be the first integrated demonstration of laser diodes, crystals, and gas cooling within a scalable laser architecture. This report is intended to summarize the progress accomplished during the first three years of the project. Due to the technological challenges associated with production of 900 nm diode-bars, heatsinks, and high optical-quality Yb:S-FAP crystals, the initial focus of the project was primarily centered on the R&D in these three areas. During the third year of the project, the R&D continued in parallel with the development of computer codes, partial activation of the laser, component testing, and code validation where appropriate.
Date: May 23, 2000
Creator: Bayramian, A.; Beach, R.; Bibeau, C.; Chanteloup, J.; Ebbers, C.; Emanuel, M. et al.
Object Type: Report
System: The UNT Digital Library
GaInNAs Laser Gain (open access)

GaInNAs Laser Gain

The optical gain spectra for GaInNAs/GaAs quantum wells are computed using a microscopic laser theory. From these spectra, the peak gain and carrier radiative decay rate as functions of carrier density are determined. These dependences allow the study of the lasing threshold current density of GaInNAs/GaAs quantum well structures.
Date: May 23, 2000
Creator: Chow, Weng W.; Jones, Eric D.; Modine, Normand A.; Kurtz, Steven R. & Allerman, Andrew A.
Object Type: Article
System: The UNT Digital Library
Homelessness: Consolidating HUD's McKinney Programs (open access)

Homelessness: Consolidating HUD's McKinney Programs

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed the potential need to consolidate homeless assistance programs administered by the Department of Housing and Urban Development (HUD), focusing on the: (1) different program requirements for HUD's four Stewart B. McKinney Homeless Assistance Act programs--the Emergency Shelter Grants Program, the Supportive Housing Program, the Shelter Plus Care Program, and the Section 8 Single-Room Occupancy Program; (2) coordination and administrative challenges that the four programs pose; and (3) actions that HUD has taken to overcome these challenges."
Date: May 23, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
HORIZONTAL DROP OF THE NAVAL SNF LONG WASTE PACKAGE ON UNYIELDING SURFACE (open access)

HORIZONTAL DROP OF THE NAVAL SNF LONG WASTE PACKAGE ON UNYIELDING SURFACE

The objective of this calculation is to determine the structural response of a Naval Spent Nuclear Fuel (SNF) Long Waste Package (WP) subjected to a 2.4-m horizontal drop on an unyielding surface (US). The scope of this document is limited to reporting the calculation results in terms of maximum stress intensities. This calculation is associated with the waste package design and was performed by the Waste Package Design section in accordance with the development plan for ''Horizontal Drop of the Naval SNF Long Waste Package on Unyielding Surface''.
Date: May 23, 2000
Creator: Schmitt, T.
Object Type: Report
System: The UNT Digital Library
Immigration and Naturalization Service: Information on the Disposition of Naturalization Cases and on Courtesy as a Factor in Employee Performance Appraisals (open access)

Immigration and Naturalization Service: Information on the Disposition of Naturalization Cases and on Courtesy as a Factor in Employee Performance Appraisals

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on the Immigration and Naturalization Service's (INS) naturalization application processing, focusing on: (1) the disposition of naturalization cases from the Chicago District Office that were lost at the Nebraska Service Center in 1997 or 1998; and (2) determining if INS employee performance appraisals included a dimension pertaining to the courteousness with which staff provide service to customers."
Date: May 23, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Issues in emissions testing of hybrid electric vehicles. (open access)

Issues in emissions testing of hybrid electric vehicles.

Argonne National Laboratory (ANL) has tested more than 100 prototype HEVs built by colleges and universities since 1994 and has learned that using standardized dynamometer testing procedures can be problematic. This paper addresses the issues related to HEV dynamometer testing procedures and proposes a new testing approach. The proposed ANL testing procedure is based on careful hybrid operation mode characterization that can be applied to certification and R and D. HEVs also present new emissions measurement challenges because of their potential for ultra-low emission levels and frequent engine shutdown during the test cycles.
Date: May 23, 2000
Creator: Duoba, M.; Anderson, J. & Ng, H.
Object Type: Article
System: The UNT Digital Library
Linear Corrugating - Final Technical Report (open access)

Linear Corrugating - Final Technical Report

Linear Corrugating is a process for the manufacture of corrugated containers in which the flutes of the corrugated medium are oriented in the Machine Direction (MD) of the several layers of paper used. Conversely, in the conventional corrugating process the flutes are oriented at right angles to the MD in the Cross Machine Direction (CD). Paper is stronger in MD than in CD. Therefore, boxes made using the Linear Corrugating process are significantly stronger-in the prime strength criteria, Box Compression Test (BCT) than boxes made conventionally. This means that using Linear Corrugating boxes can be manufactured to BCT equaling conventional boxes but containing 30% less fiber. The corrugated container industry is a large part of the U.S. economy, producing over 40 million tons annually. For such a large industry, the potential savings of Linear Corrugating are enormous. The grant for this project covered three phases in the development of the Linear Corrugating process: (1) Production and evaluation of corrugated boxes on commercial equipment to verify that boxes so manufactured would have enhanced BCT as proposed in the application; (2) Production and evaluation of corrugated boxes made on laboratory equipment using combined board from (1) above but having dual manufactures joints …
Date: May 23, 2000
Creator: Chapman, Lloyd
Object Type: Report
System: The UNT Digital Library
Linear Multigrid Techniques in Self-consistent Electronic Structure Calculations (open access)

Linear Multigrid Techniques in Self-consistent Electronic Structure Calculations

Ab initio DFT electronic structure calculations involve an iterative process to solve the Kohn-Sham equations for an Hamiltonian depending on the electronic density. We discretize these equations on a grid by finite differences. Trial eigenfunctions are improved at each step of the algorithm using multigrid techniques to efficiently reduce the error at all length scale, until self-consistency is achieved. In this paper we focus on an iterative eigensolver based on the idea of inexact inverse iteration, using multigrid as a preconditioner. We also discuss how this technique can be used for electrons described by general non-orthogonal wave functions, and how that leads to a linear scaling with the system size for the computational cost of the most expensive parts of the algorithm.
Date: May 23, 2000
Creator: Fattebert, J-L
Object Type: Article
System: The UNT Digital Library
Mechanisms affecting emission in rare-earth-activated phosphors (open access)

Mechanisms affecting emission in rare-earth-activated phosphors

The relatively poor efficiency of phosphor materials in cathodoluminescence with low accelerating voltages is a major concern in the design of field emission flat panel displays operated below 5 kV. The authors research on rare-earth-activated phosphors indicates that mechanisms involving interactions of excited activators have a significant impact on phosphor efficiency. Persistence measurements in photoluminescence (PL) and cathodoluminescence (CL) show significant deviations from the sequential relaxation model. This model assumes that higher excited manifolds in an activator de-excite primarily by phonon-mediated sequential relaxation to lower energy manifolds in the same activator ion. In addition to sequential relaxation, there appears to be strong coupling between activators, which results in energy transfer interactions. Some of these interactions negatively impact phosphor efficiency by nonradiatively de-exciting activators. Increasing activator concentration enhances these interactions. The net effect is a significant degradation in phosphor efficiency at useful activator concentrations, which is exaggerated when low-energy electron beams are used to excite the emission.
Date: May 23, 2000
Creator: Tallant, David R.; Seager, Carleton H. & Simpson, Regina L.
Object Type: Article
System: The UNT Digital Library
Mesoscopic-scale observations of surface alloying, surface phase transitions, domain coarsening, and 3-D island growth: Pb on Cu(100) (open access)

Mesoscopic-scale observations of surface alloying, surface phase transitions, domain coarsening, and 3-D island growth: Pb on Cu(100)

Low energy electron microscopy (LEEM) is used to investigate the dynamics of Pb overlayer growth on Cu(100). By following changes in surface morphology during Pb deposition, the amount of Cu transported to the surface as the Pb first alloys into the surface during formation of the c(4x4) phase and subsequently de-alloys during conversion to the c(2x2) phase is measured. The authors find that the added coverage of Cu during alloying is consistent with the proposed model for the c(4x4) alloy phase, but the added coverage during de-alloying is not consistent with the accepted model for the c(2x2) phase. To account for the discrepancy, the authors propose that Cu atoms are incorporated in the c(2x2) structure. Island growth and step advancement during the transition from the c(2x2) to c(5{radical}2x{radical}2)R45{degree} structure agrees with this model. The authors also use the LEEM to identify the order and temperature of the two-dimensional melting phase transitions for the three Pb/Cu(100) surface structures. Phase transitions for the c(5{radical}2x{radical}2)R45{degree} and c(4x4) structures are first-order, but the c(2x2) transition is second order. They determine that rotational domains of the c(5{radical}2x{radical}2)R45{degree} structure coarsen from nanometer- to micron-sized dimensions with relatively mild heating ({approximately}120 C), whereas coarsening of c(4x4) domains …
Date: May 23, 2000
Creator: Kellogg, Gary Lee & Plass, Richard A.
Object Type: Article
System: The UNT Digital Library
National Credit Union Central Liquidity Facility Lending Before the Year 2000 Date Change (open access)

National Credit Union Central Liquidity Facility Lending Before the Year 2000 Date Change

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the lending activity of the National Credit Union Central Liquidity Facility (CLF), focusing on: (1) CLF's lending during October through December 1999; and (2) credit union borrowing from the discount window and the comparison between credit unions' cost of borrowing from CLF to the cost of alternative sources of liquidity."
Date: May 23, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Neutrons and antimony neutronic evaluations (open access)

Neutrons and antimony neutronic evaluations

The new experimental results and recent extensive model development discussed in the companion report ANL/NDM-149 [Smi00], the new resonance parameterization of ref. [Mug99] and experimental results and models available in the literature, are used to construct neutronic evaluations for {sup 121}Sb and {sup 123}Sb in the ENDF/B-6 formats. These are comprehensive evaluations extending from thermal energies to 30 MeV, and include all reactions and processes commonly used in applied neutronic calculations. Comparisons are made with ENDF/B-6 MAT 5125 and 5131 files [ENDF].
Date: May 23, 2000
Creator: Smith, A. B. & Fessler, A.
Object Type: Report
System: The UNT Digital Library
Neutrons and antimony physical measurements and interpretations (open access)

Neutrons and antimony physical measurements and interpretations

New experimental information for the elastic and inelastic scattering of {approx} 4--10 MeV neutrons from elemental antimony is presented. The differential measurements are made at {approx} 40 or more scattering angles and at incident neutron-energy intervals of {approx} 0.5 MeV. The present experimental results, those previously reported from this laboratory and as found in the literature are comprehensively interpreted using spherical optical-statistical and dispersive-optical models. Direct vibrational processes via core-excitation, isospin and shell effects are discussed. Antimony models for applications are proposed and compared with global, regional, and specific models reported in the literature.
Date: May 23, 2000
Creator: Smith, A. B.
Object Type: Report
System: The UNT Digital Library