246 Matching Results

Results open in a new window/tab.

Investigations of substitutional impurity segregation to the {Sigma}5(310)/[001] STGB in FCC metals: a EFTEM and HRTEM study (open access)

Investigations of substitutional impurity segregation to the {Sigma}5(310)/[001] STGB in FCC metals: a EFTEM and HRTEM study

Investigations of the {Sigma}5 symmetric tilt grain boundaries (STGB) in face-centered cubic (FCC) metals in four different metal systems were performed. The metals we have chosen include pure Aluminum, pure Copper, Copper with 1at% Silver, and Aluminum with 1at% Copper. The model grain boundaries have been fabricated with ultra-high vacuum diffusion bonding of single crystals. With the controlled fabrication and preparation of bicrystals we are able to determine composition, structure and morphology of grain boundaries which depends on geometry, crystal orientation, impurity concentration and temperature. The limiting factor in this approach is the ability to fabricate well defined, precisely oriented interfaces, which is enabled here with the UHV Diffusion Bonding Machine [1]. The relation between grain boundary energy and impurity segregation to the interface have been theoretically calculated for the {Sigma}5 (310)/[001] interfaces within the Local Density Approximation (LDA). The calculations use a plane-wave basis and ultrasoft pseudopotentials [2]. The overall structure, especially for the Al interface is qualitatively similar to previous predictions based on pair-potential calculations. These theoretical calculations of the interface structure indicates that the Cu and the Ag atoms segregate to distinct atomic sites at the interface. High resolution electron microscopy (HRTEM) have been used to reveal …
Date: March 1, 2000
Creator: Plitzko, J M; Campbell, G H; King, W E & Foiles, S M
Object Type: Article
System: The UNT Digital Library
The Gayly Oklahoman (Oklahoma City, Okla.), Vol. 18, No. 5, Ed. 1 Wednesday, March 1, 2000 (open access)

The Gayly Oklahoman (Oklahoma City, Okla.), Vol. 18, No. 5, Ed. 1 Wednesday, March 1, 2000

Semi-monthly newspaper from Oklahoma City, Oklahoma that includes local, state, and national news and advertising of interest to the Lesbian, Gay, Bisexual, and Transgender (LGBT) community.
Date: March 1, 2000
Creator: Hawkins, Don
Object Type: Newspaper
System: The UNT Digital Library
Running the AGS MMPS at 5 HZ, 24 GEV (open access)

Running the AGS MMPS at 5 HZ, 24 GEV

N/A
Date: March 1, 2000
Creator: I., Marneris & Ruggiero, A. G.
Object Type: Report
System: The UNT Digital Library
Renewable Energy Deployment in the Federal Sector: A Status Report (Preprint) (open access)

Renewable Energy Deployment in the Federal Sector: A Status Report (Preprint)

Executive Order 13123 directs Federal agencies to expand their use of renewable energy at Federal facilities. It also requires the Secretary of Energy to develop goals for the amount of energy generated from renewable resources-such as solar, wind, and biomass-that will be used at those facilities by a certain year. This paper lists key provisions of the Executive Order dealing with renewable energy. It also describes (1) the Federal sector's extensive prior experience with renewable resources and energy systems, and (2) progress up to date (Spring 2000) in meeting the goals of the Executive Order. This progress included a Federal Working Group tasked with developing goals and guidelines for Federal use of renewable energy systems. The next step was to submit a draft goal and plan to the Secretary of Energy for approval and implementation among Federal agencies.
Date: March 1, 2000
Creator: Carlisle, N.
Object Type: Article
System: The UNT Digital Library
Legal Issues Affecting the Right of State Employees to Bring Suit Under the Age Discrimination in Employment Act and Other Federal Labor Laws (open access)
Microfabricated multi-frequency particle impedance characterization system (open access)

Microfabricated multi-frequency particle impedance characterization system

We have developed a microfabricated flow-through impedance characterization system capable of performing AC, multi-frequency measurements on cells and other particles. The sensor measures both the resistive and reactive impedance of passing particles, at rates of up to 100 particles per second. Its operational bandwidth approaches 10 MHz with a signal-to-noise ratio of approximately 40 dB. Particle impedance is measured at three or more frequencies simultaneously, enabling the derivation of multiple particle parameters. This constitutes an improvement to the well-established technique of DC particle sizing via the Coulter Principle. Human peripheral blood granulocyte radius, membrane capacitance, and cytoplasmic conductivity were measured (r = 4.1 {micro}m, C{sub mem} = 0.9 {micro}F/cm{sup 2}, {sigma}{sub int} = 0.66 S/m) and were found to be consistent with published values.
Date: March 1, 2000
Creator: Fuller, C. K.; Hamilton, J.; Ackler, H.; Krulevitch, P.; Boser, B.; Eldredge, A. et al.
Object Type: Article
System: The UNT Digital Library
Progress with the lick adaptive optics system (open access)

Progress with the lick adaptive optics system

Progress and results of observations with the Lick Observatory Laser Guide Star Adaptive Optics System are presented. This system is optimized for diffraction-limited imaging in the near infrared, 1-2 micron wavelength bands. We describe our development efforts in a number of component areas including, a redesign of the optical bench layout, the commissioning of a new infrared science camera, and improvements to the software and user interface. There is also an ongoing effort to characterize the system performance with both natural and laser guide stars and to fold this data into a refined system model. Such a model can be used to help plan future observations, for example, predicting the point-spread function as a function of seeing and guide star magnitude.
Date: March 1, 2000
Creator: Gavel, D T; Olivier, S S; Bauman, B; Max, C E & Macintosh, B
Object Type: Article
System: The UNT Digital Library
Inertial Conference Fusion Semiannual Report October 1999 - March 2000, Volume 1, Number 1 (open access)

Inertial Conference Fusion Semiannual Report October 1999 - March 2000, Volume 1, Number 1

This first issue of the ''ICF Semiannual Report'' contains articles whose diverse subjects attest to the broad technical and scientific challenges that are at the forefront of the ICF program at LLNL. The first article describes the progress being made at solving the surface roughness problem on capsule mandrels. All NIF capsule options, except machined beryllium, require a mandrel upon which the ablator is deposited. This mandrel sets the baseline sphericity of the final capsule. Problems involving defects in the mandrel have been overcome using various techniques so that 2-mm-size mandrels can now be made that meet the NIF design specification. The second article validates and provides a detailed numerical investigation of the shadowgraph technique currently used to diagnose the surface roughness of a fuel ice layer inside of a transparent capsule. It is crucial for the success of the indirect-drive ignition targets that the techniques used to characterize ice-surface roughness be well understood. This study identifies methods for analyzing the bright band that give an accurate measure of the ice-surface roughness. The third article describes a series of realistic laser and target modifications that can lead to 3-4 times more energy coupling and 10 times greater yield from a …
Date: March 1, 2000
Creator: Hammel, B. A.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Lasershot peening--a means to strengthen metals (open access)

Lasershot peening--a means to strengthen metals

Lasershot peening is an emerging modern process that impresses a compressive stress into the surfaces of metals, improving their operational lifetime. Almost everyone is familiar with taking a strip of metal or a wire and bending it multiple times until it breaks. In this situation, when the metal is bent, the surface of outer radius is stretched into a tensile state. Under tension, any flaw or micro-crack will grow in size with each bending of the metal until the crack grows through the entire strip, breaking it into two pieces. Flexure of metal components occurs in most applications. The teeth of a transmission gear flex as they deliver torque in a vehicle. Springs and valves flex every time they transfer loads. If fatigue failure from flexing occurs in the tooth of a transmission gear of light or heavy vehicles, in a fan blade of a diesel engine, in shock-absorbers or safety-related supporting structures, significant loss of assets and potentially loss of human life occurs. Lasershot peening, better than any other technique, has the potential to extend the fatigue lifetime of metal components. In the process, the laser generates a high intensity shock wave at the surface of the metal, straining …
Date: March 1, 2000
Creator: Chen, H. L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Initial Package Design Concepts Integrated Product Team (IPT) Summary Report (open access)

Initial Package Design Concepts Integrated Product Team (IPT) Summary Report

Initially, the question of transporting TRU waste to WIPP was raised as part of the EM Integration activities. The issue was re-examined as part of the system-wide view to re-engineer the TRU waste program. Consequently, the National Transportation Program and the National TRU Waste Program, in a cooperative effort, made a commitment to EM-20 to examine the feasibility of using rail to transport TRU waste material to WIPP. In December of 1999 Mr. Philip Altomare assembled a team of subject matter experts (SME) to define initial concepts for a Type B package capable of shipping TRU waste by rail (see Attachment 1 for a list of team members). This same team of experts also provided input to a preliminary study to determine if shipping TRU waste by rail could offer cost savings or other significant advantages over the current mode of operation using TRUPACT-II packages loaded on truck. As part of the analysis, the team also identified barriers to implementing rail shipments to WIPP and outlined a path forward. This report documents the findings of the study and its initial set of recommendations. As the study progressed, it was expanded to include new packages for truck as well as rail …
Date: March 1, 2000
Creator: Moss, J. & Luke, Dale Elden
Object Type: Report
System: The UNT Digital Library
Success in Managing Waste With No Identified Path to Disposal at the INEEL (open access)

Success in Managing Waste With No Identified Path to Disposal at the INEEL

The Idaho National Engineering and Environmental Laboratory (INEEL) is aggressively managing waste with no identified path to disposal (WNPD), which was previously termed special case waste (SCW). As a result of several years of this aggressive management, the INEEL has reduced its WNPD volume from approximately 38,000 m3 in 1993 to approximately 6.33 m3 in 1999. This paper discusses how the INEEL reduced its WNPD volume. It specifically discusses the beryllium reflector waste produced from the Advanced Test Reactor (ATR) as an example of the INEEL's success in managing its WNPD. The INEEL's success in reducing its WNPD volume is the result of establishing long-range strategic objectives and consistently allocating an annual budget to implement specific work tasks that are consistent with these objectives. In addition, specific short- and long-range work tasks were developed and documented in work control documents. The work tasks are evaluated annually for consistency with the strategic objectives. Since the INEEL has successfully reduced its WNPD volume, it is now focusing on disposing of the remaining volume and preventing future generation of WNPD. As a result of this focused effort, a life-cycle disposal plan was developed for the Advanced Test Reactor (ATR) beryllium waste. This plan …
Date: March 1, 2000
Creator: Mullen, Carlan K.; Carboneau, Michael Leonard & Leavitt, Max Russell
Object Type: Article
System: The UNT Digital Library
Phosphazene Silicate Nanocomposites. A Survey of Materials Properties and Synthetic Methods Using New Catalysts (open access)

Phosphazene Silicate Nanocomposites. A Survey of Materials Properties and Synthetic Methods Using New Catalysts

In the ceramics community, manipulation of synthetic conditions such as the choice of acid, base or ionic species as catalysts, aging of precursor solutions, and choice of sintering temperatures in the formation of silicate networks are known to produce radically different glass and ceramic morphologies.1 Implementation of these approaches has been attempted for some organic polymer based hybrid nanocomposites2 but not for polyphosphazene silicate composites. The desire to create unique and novel network morphologies became the impetus for establishing new catalysis protocols. The surprising inability to reproduce the mechanical properties of a well-established benchmark composite material from the literature,3 was one principal driver that initiated this in-depth investigation into the roles that the nature and amount of catalysts play in the production and physical properties of these composites.
Date: March 1, 2000
Creator: Harrup, Mason Kurt; Wertsching, Alan Kevin & Stewart, Frederick Forrest
Object Type: Article
System: The UNT Digital Library
Polysiloxane Encapsulation of High Level Calcine Waste for Transportation or Disposal (open access)

Polysiloxane Encapsulation of High Level Calcine Waste for Transportation or Disposal

This report presents the results of an experimental study investigating the potential uses for silicon-polymer encapsulation of High Level Calcine Waste currently stored within the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory (INEEL). The study investigated two different applications of silicon polymer encapsulation. One application uses silicon polymer to produce a waste form suitable for disposal at a High Level Radioactive Waste Disposal Facility directly, and the other application encapsulates the calcine material for transportation to an offsite melter for further processing. A simulated waste material from INTEC, called pilot scale calcine, which contained hazardous materials but no radioactive isotopes was used for the study, which was performed at the University of Akron under special arrangement with Orbit Technologies, the originators of the silicon polymer process called Polymer Encapsulation Technology (PET). This document first discusses the PET process, followed by a presentation of past studies involving PET applications to waste problems. Next, the results of an experimental study are presented on encapsulation of the INTEC calcine waste as it applies to transportation or disposal of calcine waste. Results relating to long-term disposal include: 1) a characterization of the pilot calcine waste; 2) …
Date: March 1, 2000
Creator: Loomis, Guy George
Object Type: Report
System: The UNT Digital Library
Remediation of Soil at Nuclear Sites (open access)

Remediation of Soil at Nuclear Sites

As the major nuclear waste and decontamination and decommissioning projects progress, one of the remaining problems that faces the nuclear industry is that of site remediation. The range of contamination levels and contaminants is wide and varied and there is likely to be a significant volume of soil contaminated with transuranics and hazardous organic materials that could qualify as mixed TRU waste. There are many technologies that offer the potential for remediating this waste but few that tackle all or most of the contaminants and even fewer that have been deployed with confidence. This paper outlines the progress made in proving the ability of Supercritical Fluid Extraction as a method of remediating soil, classified as mixed (TRU) transuranic waste.
Date: March 1, 2000
Creator: Holmes, R.; Boardman, C.; Robbins, R.; Fox, Robert Vincent & Mincher, Bruce Jay
Object Type: Article
System: The UNT Digital Library
The Oklahoma Daily (Norman, Okla.), Vol. 84, No. 116, Ed. 1 Wednesday, March 1, 2000 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 84, No. 116, Ed. 1 Wednesday, March 1, 2000

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: March 1, 2000
Creator: Wilmoth, Adam
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Baytown Sun (Baytown, Tex.), Vol. 78, No. 105, Ed. 1 Wednesday, March 1, 2000 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 78, No. 105, Ed. 1 Wednesday, March 1, 2000

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: March 1, 2000
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History
Engineering a new material for hot gas cleanup (open access)

Engineering a new material for hot gas cleanup

The engineering development of a promising sorbent for desulfurizing hot coal gas was initiated and preliminary results are presented. The sorbent is calcium-based and is designed to be regenerated and reused repeatedly. It is prepared by pelletizing powdered limestone in a rotating drum pelletizer followed by the application of a coating which becomes a strong, porous shell upon further treatment. The resulting spherical pellets combine the high reactivity of lime with the strength of an inert protective shell. Preliminary work indicates that a satisfactory shell material is comprised of a mixture of ultrafine alumina powder, somewhat coarser alumina particles, and pulverized limestone which upon heating to 1,373 K (1,100 C) becomes a coherent solid through the mechanism of particle sintering. Several batches of core-in-shell pellets were prepared and tested with encouraging results.
Date: March 1, 2000
Creator: Wheelock, T. D.; Doraiswamy, L. K. & Constant, K.
Object Type: Report
System: The UNT Digital Library
Collaborative Research: Hydrogeological-Geophysical Methods for Subsurface Site Characterization (open access)

Collaborative Research: Hydrogeological-Geophysical Methods for Subsurface Site Characterization

The significance of this project is that it addresses the issue of site characterization: not only is this issue a very significant budget item in the site clean-up effort, but also it is now realized that accurate and reliable site characterization is the key to the success of any cleanup effort. Our research objective is to develop methodologies for inexpensive high resolution imaging of natural heterogeneities and for relating these heterogeneities to the hydrogeologic parameters that control flow and contaminant transport. Our focus is to help establish the scientific basis for applying shallow geophysics to hydrogeological problems, through sediment-rock physics. This includes identifying uncertainties in applying shallow geophysics interpretations to hydrogeological site characterization.
Date: March 1, 2000
Creator: Rubin, Yoram; Morrison, Frank & Rector, Jamie
Object Type: Report
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 100, No. 296, Ed. 1 Wednesday, March 1, 2000 (open access)

Altus Times (Altus, Okla.), Vol. 100, No. 296, Ed. 1 Wednesday, March 1, 2000

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: March 1, 2000
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Alvin Advertiser (Alvin, Tex.), Ed. 1 Wednesday, March 1, 2000 (open access)

The Alvin Advertiser (Alvin, Tex.), Ed. 1 Wednesday, March 1, 2000

Weekly newspaper from Alvin, Texas that includes local, state, and national news along with advertising.
Date: March 1, 2000
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Double Oak Gazette (Double Oak, Tex.), Vol. 25, No. 3, Ed. 1 Wednesday, March 1, 2000 (open access)

The Double Oak Gazette (Double Oak, Tex.), Vol. 25, No. 3, Ed. 1 Wednesday, March 1, 2000

Monthly newspaper from Double Oak, Texas that includes news, information, and entertainment for residents of the Double Oak community along with advertising.
Date: March 1, 2000
Creator: Johnson, LaRue
Object Type: Newspaper
System: The Portal to Texas History
The East Tennessee Technology Park Progress Report for the Tennessee Hazardous Waste Reduction Act for Calendar Year 1999 (open access)

The East Tennessee Technology Park Progress Report for the Tennessee Hazardous Waste Reduction Act for Calendar Year 1999

This report is prepared for the East Tennessee Technology Park (formerly the Oak Ridge K-25 Site) (ETTP) in compliance with the ''Tennessee Hazardous Waste Reduction Act of 1990'' (THWRA) (TDEC 1990), Tennessee Code Annotated 68-212-306. Annually, THWRA requires a review of the site waste reduction plan, completion of summary waste reduction information as part of the site's annual hazardous waste reporting, and completion of an annual progress report analyzing and quantifying progress toward THWRA-required waste stream-specific reduction goals. This THWRA-required progress report provides information about ETTP's hazardous waste streams regulated under THWRA and waste reduction progress made in calendar year (CY) 1999. This progress report also documents the annual review of the site plan, ''Oak Ridge Operations Environmental Management and Enrichment Facilities (EMEF) Pollution Prevention Program Plan'', BJC/OR-306/R1 (Bechtel Jacobs Company 199a). In 1996, ETTP established new goal year ratios that extended the goal year to CY 1999 and targeted 50 percent waste stream-specific reduction goals. In CY 1999, these CY 1999 goals were extended to CY 2000 for all waste streams that generated waste in 1999. Of the 70 ETTP RCRA waste streams tracked in this report from base years as early as CY 1991, 51 waste streams met …
Date: March 1, 2000
Creator: LLC, Bechtel Jacobs Company
Object Type: Report
System: The UNT Digital Library
The Adiabatic Matching Section Solution for the Source Injector (open access)

The Adiabatic Matching Section Solution for the Source Injector

Typical designs for a Heavy Ion Fusion Power Plant require the source injector to deliver 100 beams, packed into an array with a spacing of 7 cm. When designing source injectors using a single large aperture source for each beam, the emitter surfaces are packed into an array with a spacing of 30 cm. Thus, the matching section of the source injector must not only prepare the beam for transport in a FODO lattice, but also funnel the beams together. This can be accomplished by an ESQ matching section in which each beam travels on average at a slight angle to the axis of the quadrupoles and uses the focusing effect of the FODO lattice to maintain the angle. At the end of the matching section, doublet steering is used to bring the beams parallel to each other for injection into the main accelerator. A specific solution of this type for an 84-beam source injector is presented.
Date: March 1, 2000
Creator: Ahle, L.; Grote, D. P.; Halaza, E.; Henestroza, E.; Kwan, J. W. & MacLaren, S. A.
Object Type: Article
System: The UNT Digital Library
Test Plan for Measuring Ventilation Rates and Combustible Gas Levels in TWRS Active Catch Tanks (open access)

Test Plan for Measuring Ventilation Rates and Combustible Gas Levels in TWRS Active Catch Tanks

The purpose of this data collection activity is to obtain data for a screening of combustible gases in catch tanks that are currently operated by the River Protection Project (RPP). The results will be used to support closure of the flammable gas unreviewed safety question for these facilities. The data collection will be conducted in accordance with the ''Tank Safety Screening Data Quality Objective'' (Dukelow et al. 1995). Combustible gas, ammonia, and organic vapor levels in the headspace of the catch tanks will be field-measured using hand-held instruments. If a combustible gas level measurement in a tank exceeds an established threshold, vapor grab samples (i.e., Hoke and SUMMA) will be collected for laboratory analysis. In addition, ventilation rates of some catch tanks will be determine using the tracer gas injection method to evaluate removal of flammable gas by air flowing through the tanks. This test plan identifies the field tests, sample collection, laboratory analysis, quality assurance, and reporting objectives for this data collection effort. The plan also provides step-by-step direction for field measurement of combustible gas concentrations and determination of ventilation rates.
Date: March 1, 2000
Creator: NGUYEN, D.M.
Object Type: Report
System: The UNT Digital Library