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DEVELOPMENT OF A CALCIUM-BASED SORBENT FOR HOT GAS CLEANUP (open access)

DEVELOPMENT OF A CALCIUM-BASED SORBENT FOR HOT GAS CLEANUP

The preparation and testing of potential sorbents for removing H{sub 2}S and COS from hot coal gas continued. Two preparation methods received the most consideration. Both methods involve pelletizing powders in a revolving drum under moist conditions followed either by heat treatment or steam curing to harden the pellets, depending on the particle bonding mechanism. One method was used to pelletize mixtures of calcium carbonate and either alumina or a calcium aluminate cement in a single step. Another method was used to pelletize powdered limestone in an initial step followed by the application of a coating consisting of both limestone and a hydraulic cement in a second step. By employing this method, an especially promising material was produced consisting of a limestone core surrounded by a shell consisting initially of 80 wt.% limestone and 20% wt.% calcium aluminate cement. The best material exhibited both an acceptable crushing strength and adsorption capacity for H{sub 2}S.
Date: March 31, 1999
Creator: Wheelock, T. D.; Doraiswamy, L. K. & Constant, K.
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT OF AN ON-LINE COAL WASHABILITY ANALYZER (open access)

DEVELOPMENT OF AN ON-LINE COAL WASHABILITY ANALYZER

Washability analysis is the basis for nearly all coal preparation plant separations. Unfortunately, there are no on-line techniques for determining this most fundamental of all coal cleaning information. In light of recent successes at the University of Utah, it now appears possible to determine coal washability on-line through the use of x-ray computed tomography (CT) analysis. The successful development of such a device is critical to the establishment of process control and automated coal blending systems. In this regard, Virginia Tech, Terra Tek Inc., and several eastern coal companies have joined with the University of Utah and agreed to undertake the development of a x-ray CT-based on-line coal washability analyzer with financial assistance from DOE. The three-year project will cost $594,571, of which 33% ($194,575) will be cost-shared by the participants. The project involves development of appropriate software and extensive testing/evaluation of well-characterized coal samples from operating coal preparation plants. Each project participant brings special expertise to the project which is expected to create a new dimension in coal cleaning technology. Finally, it should be noted that the analyzer may prove to be a universal analyzer capable of providing not only washability analysis, but also particle size distribution analysis, ash …
Date: March 31, 1999
Creator: Lin, C.L.; Luttrell, G.H.; Adel, G.T. & Miller, Jan D.
Object Type: Report
System: The UNT Digital Library
District of Columbia Public Schools: Audit Confirms Reasonableness of Enrollment Count, but Report's Presentation Is Unclear (open access)

District of Columbia Public Schools: Audit Confirms Reasonableness of Enrollment Count, but Report's Presentation Is Unclear

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed an independent audit of the District of Columbia Public Schools' (DCPS) enrollment counts, which is required by the District of Columbia School Reform Act of 1995, focusing on whether the: (1) audit methodology was reasonable; and (2) audit report's presentation was clear and complete."
Date: March 31, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
DNA Uptake by Transformable Bacteria (open access)

DNA Uptake by Transformable Bacteria

The various processes of DNA uptake by cells can be categorized as: viral DNA entry, conjugation, or transformation. Within each category, a variety of mechanisms have been found. However, considerable similarities occur among the different mechanisms of conjugation and, especially, transformation. All of these natural mechanisms of DNA transfer are quite elaborate and involve multiple protein components, as the case may be, of the virus, the donor cell, and the recipient cell. The mechanisms of viral infection and conjugation will be discussed mainly with respect to their relevance to transformation.
Date: March 31, 1999
Creator: Lacks, Sanford A.
Object Type: Article
System: The UNT Digital Library
Energy Technology Division research summary - 1999. (open access)

Energy Technology Division research summary - 1999.

The Energy Technology Division provides materials and engineering technology support to a wide range of programs important to the US Department of Energy. As shown on the preceding page, the Division is organized into ten sections, five with concentrations in the materials area and five in engineering technology. Materials expertise includes fabrication, mechanical properties, corrosion, friction and lubrication, and irradiation effects. Our major engineering strengths are in heat and mass flow, sensors and instrumentation, nondestructive testing, transportation, and electromechanics and superconductivity applications. The Division Safety Coordinator, Environmental Compliance Officers, Quality Assurance Representative, Financial Administrator, and Communication Coordinator report directly to the Division Director. The Division Director is personally responsible for cultural diversity and is a member of the Laboratory-wide Cultural Diversity Advisory Committee. The Division's capabilities are generally applied to issues associated with energy production, transportation, utilization, or conservation, or with environmental issues linked to energy. As shown in the organization chart on the next page, the Division reports administratively to the Associate Laboratory Director (ALD) for Energy and Environmental Science and Technology (EEST) through the General Manager for Environmental and Industrial Technologies. While most of our programs are under the purview of the EEST ALD, we also have had …
Date: March 31, 1999
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Estimating the Maximum Splat Diameter of a Solidifying Droplet (open access)

Estimating the Maximum Splat Diameter of a Solidifying Droplet

We present a simple analytical model for the estimation of the maximum splat diameter of an impacting droplet on a subcooled target. This work is an extension of the isothermal model of Pasandideh-Fard et al. (1996). The model uses an energy conservation argument, applied between the initial and final drop configurations, to approximately capture the dynamics of spreading. The effects of viscous dissipation, surface tension, and contact angle are taken into account. Tests against limited experimental data at high Reynolds and Weber numbers indicate that an accuracy of the order of 5% is achieved with no adjustable parameters required. Agreement with experimental data in the limit We {yields} {infinity} is also very good. We additionally propose a simple model for the estimation of the thickness of the freezing layer developed at the droplet-substrate contact during droplet spreading. This model accounts for the effect of thermal contact resistance and its predictions compare favorably with experimental data.
Date: March 31, 1999
Creator: Hadjiconstantinou, N.G.
Object Type: Article
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Wednesday, March 31, 1999 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Wednesday, March 31, 1999

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: March 31, 1999
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History

Faculty Recital: 1999-03-31 Walter Gray, cello and James Gillespie, clarinet, Steven Harlos, piano

Access: Use of this item is restricted to the UNT Community
A faculty cello recital performed at the UNT College of Music Winspear Hall.
Date: March 31, 1999
Creator: Gray, Walter; Gillespie, James & Harlos, Steven, 1953-
Object Type: Sound
System: The UNT Digital Library
Final Report: Absorption Chiller Corrosion Protection, September 1, 1999 - March 31, 1999 (open access)

Final Report: Absorption Chiller Corrosion Protection, September 1, 1999 - March 31, 1999

None
Date: March 31, 1999
Creator: Chandler, Travis
Object Type: Report
System: The UNT Digital Library
Final Report: Measuring the Effects of a Unique Law Limiting Employee Medical Examinations to Job-Related Matters, April 1, 1997 - March 31, 1999 (open access)

Final Report: Measuring the Effects of a Unique Law Limiting Employee Medical Examinations to Job-Related Matters, April 1, 1997 - March 31, 1999

None
Date: March 31, 1999
Creator: Rothstein, Mark A.; Gelb, Betsy D. & Craig, Steven G.
Object Type: Report
System: The UNT Digital Library
Final Report: Task Force on requirements for HPC software: Guidelines for specifying HPC software, June 1, 1997 - August 31, 1999 (open access)

Final Report: Task Force on requirements for HPC software: Guidelines for specifying HPC software, June 1, 1997 - August 31, 1999

This document describes the results of a task force convened to determine what types of system software and tools were sufficiently important to warrant implementation across multiple vendors and machine types. The group included representatives from a wide range of user sites, as well as from the software development groups at vendor sites. Together, they established key software requirements, identified priorities for different types of user organizations, and formulated the requirements into language suitable for direct inclusion in procurements and requests-for-bids. The report is structured into four sections. The first discusses the formation and objectives of the task force and the processes used to arrive at consensus. Part 2 outlines the group's assumptions about how software will be specified on RFPs for parallel and clustered computers. In the next section, a tabular summary describes the requirements and the priority rank that was assigned to each. Part 4 presents the wording that is recommended for specifying each software element. Examples of how the requirements might be applied for various RFP scenarios, are in the appendices, which also provide vendor estimations of the level-of-effort required to develop and supply each requirement. The task force was sponsored by the Parallel Tools Consortium and …
Date: March 31, 1999
Creator: Pancake, Cherri M.
Object Type: Report
System: The UNT Digital Library
Financial Audit: 1998 Financial Report of the United States Government (open access)

Financial Audit: 1998 Financial Report of the United States Government

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO reviewed the annual audited financial statements for 24 major departments and agencies of the U.S. government."
Date: March 31, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Financial Audit: Independent Counsel Expenditures for the Six Months Ended September 30, 1998 (open access)

Financial Audit: Independent Counsel Expenditures for the Six Months Ended September 30, 1998

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO presented the results of its audits of expenditures reported by seven offices of independent counsel for the 6 months ended September 30, 1998, focusing on whether the statements of expenditures complied with the financial reporting requirements of the law."
Date: March 31, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Fluidtight Seal for a Container (open access)

Fluidtight Seal for a Container

A fluidtight seal for a container is formed by abutting a metal ring with a step machined in a convexo-concave container closure device and inserting this assembly into an open end of the container. Under compressive force, the closure device deforms causing the metal ring to pivot about the step on the closure device and interact with symmetrically tapered inner walls of the container to form a fluidtight seal between the container and the closure device. The compressive force is then withdrawn without affecting the fluidtight characteristic of the seal. A destructive force against the container closure device is necessary to destroy the fluidtight seal.
Date: March 31, 1999
Creator: Morrison, Edward F.
Object Type: Patent
System: The UNT Digital Library
Forward-in-Time Differencing for Fluids: Nonhydrostatic Modeling of Rotating Stratified Flow on a Mountainous Sphere (open access)

Forward-in-Time Differencing for Fluids: Nonhydrostatic Modeling of Rotating Stratified Flow on a Mountainous Sphere

Traditionally, numerical models for simulating planetary scale weather and climate employ the hydrostatic primitive equations-an abbreviated form of Navier-Stokes equations that neglect vertical accelerations and use simplified inertial forces. 1 Although there is no evidence so far that including nonhydrostatic effects in global models has any physical significance for large scale solutions, there is an apparent trend in the community toward restoring Navier-Stokes equations (or at least their less constrained forms) in global models of atmospheres and oceans. The primary motivation for this is that the state-of-the-art computers already admit resolutions where local nonhydrostatic effects become noticeable. Other advantages include: the convenience of local mesh refinement; better overall accuracy; insubstantial computational overhead relative to hydrostatic models; universality and therefore convenience of maintaining a single large code; as well as conceptual simplicity and mathematical elegancy--features important for education. The few existing nonhydrostatic global models differ in analytic formulation and numerical design, reflecting their different purposes and origins. Much of our present research improves the design of a high-performance numerical model for simulating the flows of moist (and precipitating), rotating, stratified fluids past a specified time-dependent irregular lower boundary. This model is representative of a class of nonhydrostatic atmospheric codes employing the …
Date: March 31, 1999
Creator: Smolarkiewicz, P.K.; Grubisic, V. & Margolin, L.G.
Object Type: Article
System: The UNT Digital Library
The Gilmer Mirror (Gilmer, Tex.), Vol. 122, No. 26, Ed. 1 Wednesday, March 31, 1999 (open access)

The Gilmer Mirror (Gilmer, Tex.), Vol. 122, No. 26, Ed. 1 Wednesday, March 31, 1999

Semiweekly newspaper from Gilmer, Texas that includes local, state, and national news along with advertising.
Date: March 31, 1999
Creator: Overton, Mac
Object Type: Newspaper
System: The Portal to Texas History
Illustrated Paperboy (Cleveland, Tex.), Vol. 7, No. 1, Ed. 1 Wednesday, March 31, 1999 (open access)

Illustrated Paperboy (Cleveland, Tex.), Vol. 7, No. 1, Ed. 1 Wednesday, March 31, 1999

Weekly newspaper from Cleveland, Texas that includes local, county, and state news along with extensive advertising.
Date: March 31, 1999
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
In-Situ Air Permeability Measurements Using the Cone Permeameter at the 200 East Area of the Hanford Site (open access)

In-Situ Air Permeability Measurements Using the Cone Permeameter at the 200 East Area of the Hanford Site

This report documents the field demonstration of the Cone Permeameter{trademark} (CPer) conducted at the Immobilization Low-Activity Waste (ILAW) site in the 200 East area of the Department of Energy's (DOE) Hanford facility. The demonstration was conducted using the Hanford Site Cone Penetration Platform (CPP) shown in Figure 1.1. The purpose of the technology demonstration was to (1) gather baseline data and evaluate the CPer's ability to measure air permeability in arid sands, silts and gravels; and (2) to determine the system's ability to replicate permeability profiles with multiple pushes in close proximity. The demonstration was jointly conducted by Applied Research Associates, Inc. (ARA) and Science and Engineering Associates (SEA). This report satisfies the requirements of ARA's contract No.2075 to Lockheed Martin Hanford Company. The report is organized into six major sections. This first section presents an introduction and outline to the report. Section 2 contains a discussion of the technologies used for the demonstration. Section 3 contains a brief description of the site where the demonstration was conducted. Section 4 describes the testing methodology and chronology. Section 5 presents the results obtained during the field test program. Comparisons between these results and existing site data are developed and discussed in …
Date: March 31, 1999
Creator: TROYER, G.L.
Object Type: Report
System: The UNT Digital Library
Induced energy-saving innovation in industrial durable goods. Final report (open access)

Induced energy-saving innovation in industrial durable goods. Final report

None
Date: March 31, 1999
Creator: Newell, Richard G.
Object Type: Report
System: The UNT Digital Library
Inertial Confinement Fusion Quarterly Report January-March 1999, Volume 9, Number 2 (open access)

Inertial Confinement Fusion Quarterly Report January-March 1999, Volume 9, Number 2

This quarterly report covers the following topics: (1) Properties of and Manufacturing Methods for NIF Laser Glasses (J. H. Campbell)--The NIF amplifiers require 3380 Nd-doped laser glass slabs; continuous glass melting methods will be used for the first time to manufacture these slabs. The properties of the laser glasses are summarized and the novel continuous melting method is described. (2) Diffractive Optics for the NIF (J. A. Britten)--We have fabricated demonstration diffractive optics according to the NIF baseline design at full scale, via wet-chemical etching of patterns into fused silica. We have examined the effects of dip-coated sol-gel antireflection coatings on the performance of these optics, and have concluded that diffractive optics should remain uncoated to minimize laser-induced damage to downstream optics and to maximize environmental stability. We have also demonstrated the feasibility of combining all diffractive structures required by NIF, which vary over orders of magnitude in lateral and vertical scales, onto a single surface. (3) Producing KDP and DKDP Crystals for the NIF Laser (A. K. Burnham)--Rapid-growth KDP has overcome most of the hurdles for production of boules for NIF switch crystals and doublers, but some improvements in process reliability at the tripler's 3{omega} damage threshold are needed. …
Date: March 31, 1999
Creator: Atherton, J.
Object Type: Report
System: The UNT Digital Library
Inversion of Head Wave Traveltimes for Three-Dimensional Planar Structure (open access)

Inversion of Head Wave Traveltimes for Three-Dimensional Planar Structure

Inversion of head wave arrival times for three-dimensional (3D) planar structure is formulated as a constrained parameter optimization problem, and solved via linear programming techniques. The earth model is characterized by a set of homogeneous and isotropic layers bounded by plane, dipping interfaces. Each interface may possess arbitrary strike and dip. Predicted data consists of traveltimes of critically refracted waves formed on the plane interfaces of the model. The nonlinear inversion procedure is iterative; an initial estimate of the earth model is refined until an acceptable match is obtained between observed and predicted data. Inclusion of a priori constraint information, in the form of inequality relations satisfied by the model parameters, assists the algorithm in converging toward a realistic solution. Although the 3D earth model adopted for the inversion procedure is simple, the algorithm is quite useful in two particular contexts: (i) it can provide an initial model estimate suitable for subsequent improvement by more general techniques (i.e., traveltime tomography), and (ii) it is an effective analysis tool for investigating the power of areal recording geometries for detecting and resolving 3D dipping planar structure.
Date: March 31, 1999
Creator: Aldridge, D. F. & Oldenburg, D. W.
Object Type: Article
System: The UNT Digital Library
Investigation of mixed metal sorbent/catalysts for the simultaneous removal of sulfur and nitrogen oxides (open access)

Investigation of mixed metal sorbent/catalysts for the simultaneous removal of sulfur and nitrogen oxides

Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. …
Date: March 31, 1999
Creator: Akyurtlu, A. & Akyurtlu, J.F.
Object Type: Report
System: The UNT Digital Library
Iraq: Post-War Challenges and U.S. Responses, 1991-1998 (open access)

Iraq: Post-War Challenges and U.S. Responses, 1991-1998

None
Date: March 31, 1999
Creator: unknown
Object Type: Report
System: The UNT Digital Library
IRS Audits: Weaknesses in Selecting and Conducting Correspondence Audits (open access)

IRS Audits: Weaknesses in Selecting and Conducting Correspondence Audits

A chapter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the Internal Revenue Service's (IRS) program to audit income tax returns through correspondence, focusing on: (1) the number, results, and duration of correspondence audits as well as the characteristics of the audited returns; and (2) processes and requirements that IRS has had for years to govern correspondence audits."
Date: March 31, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library