Partner
UNT Libraries Government Documents Department
8,914
Oklahoma Historical Society
3,584
UNT Libraries Special Collections
2,357
UNT Libraries
667
UNT Music Library
546
National Museum of the Pacific War/Admiral Nimitz Foundation
310
Sterling Municipal Library
294
Carl Albert Congressional Research and Studies Center
212
UNT Honors College
116
San Antonio Public Library
102
121 More
Collection
Office of Scientific & Technical Information Technical Reports
5,288
Texas Digital Newspaper Program
3,231
Jim Argo Collection
2,404
Congressional Research Service Reports
1,828
Oklahoma Digital Newspaper Program
1,444
Tocker Foundation Grant
1,323
Government Accountability Office Reports
904
José L. Castillo Photograph Collection
566
College of Music Recordings
536
The Black Academy of Arts and Letters Records
529
213 More
Degree Department
Degree Discipline
Degree Level
Country
States
Decade
Year
Month
The Effect of Li, He and Ca on Grain Boundary Cohesive Strength in Ni
Boron is added to nickel-base superalloys such as Alloy X-750 in order to enhance high temperature strength and ductility so that the alloy may be more easily hot worked[1]. Boron additions also have been shown to ameliorate intergranular hydrogen embrittlement in nickel[2], and to improve the high temperature resistance of Alloy X-750 to aqueous stress corrosion cracking (SCC) in the absence of irradiation[3]. Recent quantum mechanical calculations demonstrate that boron strengthens grain boundaries in pure nickel[4], and may contribute to the observed benefits of boron on workability and fracture resistance of nickel alloys. Alloy X-750 exhibits greater susceptibility to intergranular stress corrosion cracking (IGSCC) when irradiated[5], and it has been proposed that the presence of grain boundary helium and/or lithium is responsible. Arguments have been advanced that helium embrittlement of the grain boundaries is primarily responsible for the greater observed susceptibility to IGSCC in irradiated X-750[1]. Alternatively, it has been proposed that lithium promotes IGSCC either by entering the water at the crack tip and lowering the local pH, or by inducing a restructuring of the grain boundary itself[1]. Direct embrittlement of grain boundaries by lithium also has been investigated by ion bombardment in Nimonic PE16, illustrating that under certain …
Date:
April 1, 2000
Creator:
Smith, Richard W.; Geng, W. T.; Geller, Clint B.; Wu, R. & Freeman, A. J.
Object Type:
Article
System:
The UNT Digital Library
Effects of Water Radiolysis in Water Cooled Reactors, NERI Proposal No.99-0010. Technical progress report
OAK B188 Effects of Water Radiolysis in Water Cooled Reactors, NERI Proposal No.99-0010. Technical progress report
Date:
April 1, 2000
Creator:
Pimblott, S.M.
Object Type:
Report
System:
The UNT Digital Library
EFFECTS OF XE ION IRRADIATION AND SUBSEQUENT ANNEALING ON THE PROPERTIES OF MAGNESIUM-ALUMINATE SPINEL
Single crystals of magnesium-aluminate spinel MgAl{sub 2}O{sub 4} were irradiated with 340 keV Xe{sup 2} ions at {minus}173 C ({approximately} 100 K). A fluence of 1 x 10{sup 20} Xe/m{sup 2} created an amorphous layer at the surface of the samples. The samples were annealed for 1 h at different temperatures ranging from 130 C to 880 C. Recrystallization took place in the temperature interval between 610 C and 855 C. Transmission electron microscopy (TEM) images show two distinct layers near the surface: (1) a polycrystalline layer with columnar grain structure; and (2) a buried damaged layer epitaxial with the substrate. After annealing at 1100 C for 52 days, the profile of implanted Xe ions did not change, which means that Xe ions are not mobile in the spinel structure up to 1100 C. The thickness of the buried damaged layer decreased significantly in the 1100 C annealed sample comparing to the sample annealed for 1 h at 855 C.
Date:
April 1, 2000
Creator:
AFANASYEV, I. & AL, ET
Object Type:
Article
System:
The UNT Digital Library
Electrochromic windows for commercial buildings: Monitored results from a full-scale testbed
Electrochromic glazings promise to be the next major advance in energy-efficient window technology, helping to transform windows and skylights from an energy liability to an energy source for the nation's building stock. Monitored results from a full-scale demonstration of large-area electrochromic windows are given. The test consisted of two side-by-side, 3.7x4.6-m, office-like rooms. In each room, five 62x173-cm lower electrochromic windows and five 62x43-cm upper electrochromic windows formed a large window wall. The window-to-exterior-wall ratio (WWR) was 0.40. The southeast-facing electrochromic windows had an overall visible transmittance (Tv) range of Tv=0.11-0.38 and were integrated with a dimmable electric lighting system to provide constant work plane illuminance and to control direct sun. Daily lighting use from the automated electrochromic window system decreased by 6 to 24% compared to energy use with static, low-transmission (Tv =0.11), unshaded windows in overcast to cle ar sky winter conditions in Oakland, California. Daily lighting energy use increased as much as 13% compared to lighting energy use with static windows that had Tv=0.38. Even when lighting energy savings were not obtainable, the visual environment produced by the electrochromic windows, indicated by well-controlled window and room luminance levels, was significantly improved for computer-type tasks throughout the day …
Date:
April 1, 2000
Creator:
Lee, Eleanor S.; DiBartolomeo, Dennis L. & Selkowitz, Stephen E.
Object Type:
Article
System:
The UNT Digital Library
ELECTROLYTIC MEMBRANE DIALYSIS FOR TREATING WASTEWATER STREAMS
This project will determine whether electrolytic dialysis has promise in the separation of charged particles in an aqueous solution. The ability to selectively move ions from one aqueous solution to another through a semipermeable membrane will be studied as a function of emf, amperage, and particle electrical charge. The ions selected for the study are Cl{sup -} and SO{sub 4}{sup 2-}. These ions are of particular interest because of their electrical conduction properties in aqueous solution resulting with their association with the corrosive action of metals. The studies will be performed with commercial membranes on solutions prepared in the laboratory from reagent salts. pH adjustments will be made with dilute reagent acid and base. Specific objectives of the project include testing a selected membrane currently available for electrolytic dialysis, membrane resistance to extreme pH conditions, the effectiveness of separating a mixture of two ions selected on the basis of size, the efficiency of the membranes in separating chloride (Cl{sup 1-}) from sulfate (SO{sub 4}{sup 2-}), and separation efficiency as a function of electromotive force (emf).
Date:
April 1, 2000
Creator:
Timpe, Ronald C.
Object Type:
Report
System:
The UNT Digital Library
Empirical support for global integrated assessment modeling: Productivity trends and technological change in developing countries' agriculture and electric power sectors
Integrated assessment (IA) modeling of climate policy is increasingly global in nature, with models incorporating regional disaggregation. The existing empirical basis for IA modeling, however, largely arises from research on industrialized economies. Given the growing importance of developing countries in determining long-term global energy and carbon emissions trends, filling this gap with improved statistical information on developing countries' energy and carbon-emissions characteristics is an important priority for enhancing IA modeling. Earlier research at LBNL on this topic has focused on assembling and analyzing statistical data on productivity trends and technological change in the energy-intensive manufacturing sectors of five developing countries, India, Brazil, Mexico, Indonesia, and South Korea. The proposed work will extend this analysis to the agriculture and electric power sectors in India, South Korea, and two other developing countries. They will also examine the impact of alternative model specifications on estimates of productivity growth and technological change for each of the three sectors, and estimate the contribution of various capital inputs--imported vs. indigenous, rigid vs. malleable-- in contributing to productivity growth and technological change. The project has already produced a data resource on the manufacturing sector which is being shared with IA modelers. This will be extended to the …
Date:
April 1, 2000
Creator:
Sathaye, Jayant A.
Object Type:
Report
System:
The UNT Digital Library
ENERGY LANDSCAPE OF 2D FLUID FORMS
The equilibrium states of 2D non-coarsening fluid foams, which consist of bubbles with fixed areas, correspond to local minima of the total perimeter. (1) The authors find an approximate value of the global minimum, and determine directly from an image how far a foam is from its ground state. (2) For (small) area disorder, small bubbles tend to sort inwards and large bubbles outwards. (3) Topological charges of the same sign repel while charges of opposite sign attract. (4) They discuss boundary conditions and the uniqueness of the pattern for fixed topology.
Date:
April 1, 2000
Creator:
Jiang, Y.; Janiaud, E.; Flament, C.; Glazier, J. A. & Granner, F.
Object Type:
Article
System:
The UNT Digital Library
Energy use and energy intensity of the U.S. chemical industry
The U.S. chemical industry is the largest in the world, and responsible for about 11% of the U.S. industrial production measured as value added. It consumes approximately 20% of total industrial energy consumption in the U.S. (1994), and contributes in similar proportions to U.S. greenhouse gas emissions. Surprisingly, there is not much information on energy use and energy intensity in the chemical industry available in the public domain. This report provides detailed information on energy use and energy intensity for the major groups of energy-intensive chemical products. Ethylene production is the major product in terms of production volume of the petrochemical industry. The petrochemical industry (SIC 2869) produces a wide variety of products. However, most energy is used for a small number of intermediate compounds, of which ethylene is the most important one. Based on a detailed assessment we estimate fuel use for ethylene manufacture at 520 PJ (LHV), excluding feedstock use. Energy intensity is estimated at 26 GJ/tonne ethylene (LHV), excluding feedstocks.The nitrogenous fertilizer production is a very energy intensive industry, producing a variety of fertilizers and other nitrogen-compounds. Ammonia is the most important intermediate chemical compound, used as basis for almost all products. Fuel use is estimated at …
Date:
April 1, 2000
Creator:
Worrell, E.; Phylipsen, D.; Einstein, D. & Martin, N.
Object Type:
Report
System:
The UNT Digital Library
Environmental Management Performance Report April 2000
The purpose of the Environmental Management Performance Report (EMPR) is to provide the Department of Energy Richland Operations Office's (DOE-RL's) report of Hanford's Environmental Management (EM) performance by: Project Hanford Management Contract (PHMC) through Fluor Hanford, Inc. (FHI) and its subcontractors; Environmental Restoration Contract through Bechtel Hanford, Inc. (BHI), and its subcontractors; Pacific Northwest National Laboratories (PNNL) for EM and EM Science and Technology (S and T) Mission; and Office of Safety Regulation of the TWRS Privatization Contractor. This report is a monthly publication that summarizes EM Site performance under RL Operations Office. It is organized by the four sections listed above, with each section containing an Executive Summary and Area Performance Summaries.
Date:
April 1, 2000
Creator:
EDER, D.M.
Object Type:
Report
System:
The UNT Digital Library
Enzymology and Molecular Biology of Cell Wall Biosynthesis. Final Technical Report
The following aspects of enzymology of cell wall synthesis were pursued under this cited grant: (1) Isolation of plasma membrane-localized glucan synthase II (GS-II) of pea; (2) Cloning of genes for possible plant GS-II components; (3) Golgi glucan synthase-I (GS-I); and (4) Golgi reversibly glycosylated protein 1 (RGP1).
Date:
April 1, 2000
Creator:
Ray, Dr. Peter M.
Object Type:
Report
System:
The UNT Digital Library
An Equilibrium-Based Model of Gas Reaction and Detonation
During gaseous diffusion plant operations, conditions leading to the formation of flammable gas mixtures may occasionally arise. Currently, these could consist of the evaporative coolant CFC-114 and fluorinating agents such as F2 and ClF3. Replacement of CFC-114 with a non-ozone-depleting substitute is planned. Consequently, in the future, the substitute coolant must also be considered as a potential fuel in flammable gas mixtures. Two questions of practical interest arise: (1) can a particular mixture sustain and propagate a flame if ignited, and (2) what is the maximum pressure that can be generated by the burning (and possibly exploding) gas mixture, should it ignite? Experimental data on these systems, particularly for the newer coolant candidates, are limited. To assist in answering these questions, a mathematical model was developed to serve as a tool for predicting the potential detonation pressures and for estimating the composition limits of flammability for these systems based on empirical correlations between gas mixture thermodynamics and flammability for known systems. The present model uses the thermodynamic equilibrium to determine the reaction endpoint of a reactive gas mixture and uses detonation theory to estimate an upper bound to the pressure that could be generated upon ignition. The model described and …
Date:
April 1, 2000
Creator:
Trowbridge, L.D.
Object Type:
Report
System:
The UNT Digital Library
Evaluation of ultramafic deposits in the Eastern United States and Puerto Rico as sources of magnesium for carbon dioxide sequestration
In this report, the authors evaluate the resource potential of extractable magnesium from ultramafic bodies located in Vermont, the Pennsylvania-Maryland-District-of-Columbia (PA-MD-DC) region, western North Carolina, and southwestern Puerto Rico. The first three regions occur in the Appalachian Mountains and contain the most attractive deposits in the eastern United States. They were formed during prograde metamorphism of serpentinized peridotite fragments originating from an ophiolite protolith. The ultramafic rocks consist of variably serpentinized dunite, harzburgite, and minor iherzolite generally containing antigorite and/or lizardite as the major serpentine minor phases. Chrysotile contents vary from minor to major, depending on occurrence. Most bodies contain an outer sheath of chlorite-talc-tremolite rock. Larger deposits in Vermont and most deposits in North Carolina contain a core of dunite. Magnesite and other carbonates are common accessories. In these deposits, MgO ranges from 36 to 48 wt % with relatively pure dunite having the highest MgO and lowest H{sub 2}O contents. Ultramafic deposits in southwestern Puerto Rico consist of serpentinized dunite and harzburgite thought to be emplaced as large diapirs or as fragments in tectonic melanges. They consist of nearly pure, low-grade serpentinite in which lizardite and chrysotile are the primary serpentine minerals. Chlorite is ubiquitous in trace amounts. …
Date:
April 1, 2000
Creator:
Goff, Fraser; Guthrie, George; Lipin, Bruce; Fite, Melissa; Chipera, Steve; Counce, Dale et al.
Object Type:
Report
System:
The UNT Digital Library
Evidence of Deepwater Spawning of Fall Chinook Salmon (Oncorhynchus Tshawytscha) : Spawning Near Ives and Pierce Island of the Columbia River, 1999.
Fall chinook salmon Oncorhynchus tshawytscha, thought to originate from Bonneville Hatchery, were first noted to be spawning downstream of Bonneville Dam by Washington Department of Fisheries and Wildlife (WDFW) biologists in 1993 (Hymer 1997). Known spawning areas include gravel beds on the Washington side of the river near Hamilton Creek and Ives island. Limited spawning ground surveys were conducted in the area around Ives and Pierce Islands during 1994-1997 and based on these surveys it was believed that fall chinook salmon successfully spawned in this area. The size of this population from 1994 to 1996 was estimated at 1,800 to 5,200 fish (Hymer 1997). Recently, chum salmon were also documented spawning downstream of Bonneville Dam. Chum salmon O. kisutch were listed as threatened under the Endangered Species Act (ESA) in March, 1999. There are several ongoing investigations to define the physical habitat characteristics associated with fall chinook and chum salmon spawning areas downstream of Bonneville Dam. A major concern is to determine what flows (i.e. surface elevations) are necessary to ensure their long-term survival. Our objective was to locate deepwater spawning locations in the main Columbia River channel and to collect additional data on physical habitat parameters at the site. …
Date:
April 1, 2000
Creator:
Mueller, Robert P. & Dauble, Dennis D.
Object Type:
Report
System:
The UNT Digital Library
Executive Guide: Creating Value Through World-class Financial Management (Supersedes AIMD-99-45)
Guidance issued by the General Accounting Office with an abstract that begins "This publication supersedes AIMD-99-45, Executive Guide: Creating Value Through World-Class Financial Management (Exposure Draft), August 1999. GAO published a guide on the financial management practices and improvement efforts of nine leading public and private sector finance organizations to identify the success factors, practices, and outcomes associated with world-class financial management. This executive guide is intended to assist federal agencies in achieving the objectives of the Chief Financial Officers Act of 1990 and subsequent related legislation by providing case studies of 11 practices critical for establishing and maintaining sound financial operations."
Date:
April 1, 2000
Creator:
United States. General Accounting Office.
Object Type:
Text
System:
The UNT Digital Library
An expandable software model for collaborative decision making during the whole building life cycle
Decisions throughout the life cycle of a building, from design through construction and commissioning to operation and demolition, require the involvement of multiple interested parties (e.g., architects, engineers, owners, occupants and facility managers). The performance of alternative designs and courses of action must be assessed with respect to multiple performance criteria, such as comfort, aesthetics, energy, cost and environmental impact. Several stand-alone computer tools are currently available that address specific performance issues during various stages of a building's life cycle. Some of these tools support collaboration by providing means for synchronous and asynchronous communications, performance simulations, and monitoring of a variety of performance parameters involved in decisions about a building during building operation. However, these tools are not linked in any way, so significant work is required to maintain and distribute information to all parties. In this paper we describe a software model that provides the data management and process control required for collaborative decision making throughout a building's life cycle. The requirements for the model are delineated addressing data and process needs for decision making at different stages of a building's life cycle. The software model meets these requirements and allows addition of any number of processes and support …
Date:
April 1, 2000
Creator:
Papamichael, K.; Pal, V.; Bourassa, N.; Loffeld, J. & Capeluto, G.
Object Type:
Article
System:
The UNT Digital Library
Experimental measurements of the thermal conductivity of ash deposits: Part 1. Measurement technique
This paper describes a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. Since ash deposit thermal conductivity is thought to be strongly dependent on deposit microstructure, the technique is designed to minimize the disturbance of the natural deposit microstructure. Traditional techniques for measuring deposit thermal conductivity generally do not preserve the sample microstructure. Experiments are described that demonstrate the technique, quantify experimental uncertainty, and determine the thermal conductivity of highly porous, unsintered deposits. The average measured conductivity of loose, unsintered deposits is 0.14 {+-} 0.03 W/(m K), approximately midway between rational theoretical limits for deposit thermal conductivity.
Date:
April 1, 2000
Creator:
Robinson, A. L.; Buckley, S. G.; Yang, N. & Baxter, L. L.
Object Type:
Report
System:
The UNT Digital Library
Experimental measurements of the thermal conductivity of ash deposits: Part 2. Effects of sintering and deposit microstructure
The authors report results from an experimental study that examines the influence of sintering and microstructure on ash deposit thermal conductivity. The measurements are made using a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. The technique is designed to minimize the disturbance of the natural deposit microstructure. The initial stages of sintering and densification are accompanied by an increase in deposit thermal conductivity. Subsequent sintering continues to densify the deposit, but has little effect on deposit thermal conductivity. SEM analyses indicates that sintering creates a layered deposit structure with a relatively unsintered innermost layer. They hypothesize that this unsintered layer largely determines the overall deposit thermal conductivity. A theoretical model that treats a deposit as a two-layered material predicts the observed trends in thermal conductivity.
Date:
April 1, 2000
Creator:
Robinson, A. L.; Buckley, S. G.; Yang, N. & Baxter, L. L.
Object Type:
Report
System:
The UNT Digital Library
FASAB News, Issue 61, April-May 2000
Other written product issued by the General Accounting Office with an abstract that begins "GAO provided information on the Federal Accounting Standards Advisory Board's recent actions, meetings, and practices."
Date:
April 1, 2000
Creator:
United States. General Accounting Office.
Object Type:
Text
System:
The UNT Digital Library
FCC Record, Volume 15, No. 10, Pages 6053 to 6636, April 3 - April 14, 2000
Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date:
April 2000
Creator:
United States. Federal Communications Commission.
Object Type:
Book
System:
The UNT Digital Library
FCC Record, Volume 15, No. 12, Pages 7254 to 7824, April 17 - April 28, 2000
Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date:
April 2000
Creator:
United States. Federal Communications Commission.
Object Type:
Book
System:
The UNT Digital Library
Feasibility of an appliance energy testing and labeling program for Sri Lanka
A feasibility study evaluated the costs and benefits of establishing a program for testing, labeling and setting minimum efficiency standards for appliances and lighting in Sri Lanka. The feasibility study included: refrigerators, air-conditioners, flourescent lighting (ballasts & CFls), ceiling fans, motors, and televisions.
Date:
April 1, 2000
Creator:
Biermayer, Peter; Busch, John; Hakim, Sajid; Turiel, Issac; du Pont, Peter & Stone, Chris
Object Type:
Report
System:
The UNT Digital Library
Final Report on Passive and Active Low-Frequency Electromagnetic Spectroscopy for Airborne Detection of Underground Facilities
The objective of this program is to perform research to advance the science in the application of both passive and active electromagnetic measurement techniques for the detection and spatial delineation of underground facilities. Passive techniques exploit the electromagnetic fields generated by electrical apparatus within the structure, including generators, motors, power distribution circuitry, as well as communications hardware and similar electronics equipment. Frequencies monitored are generally in the audio range (60-20,000 Hz), anticipating strong sources associated with normal AC power (i.e., 50 or 60 Hz and associated harmonics), and low frequency power from broad-band sources such as switching circuits. Measurements are made using receiver induction coils wired to electronics that digitize and record the voltage induced by the time varying magnetic fields. Active techniques employ electromagnetic field transmitters in the form of AC current carrying loops also in the audio frequency range, and receiving coils that measure the resultant time varying magnetic fields. These fields are perturbed from those expected in free space by any conductive material in the vicinity of the coils, including the ground, so that the total measured field is comprised of the primary free-space component and the secondary scattered component. The latter can be further delineated into …
Date:
April 2000
Creator:
SanFilipo, Bill
Object Type:
Report
System:
The UNT Digital Library
Financial Report of the United States Government, 1999
Other written product issued by the General Accounting Office with an abstract that begins "GAO presented the United States government's 1999 financial report. The report includes: (1) audited financial statements that cover the executive, legislative, and judicial branches; and (2) GAO's audit of the financial report."
Date:
April 1, 2000
Creator:
United States. General Accounting Office.
Object Type:
Text
System:
The UNT Digital Library
First year operational experience with the Cherenkov Detector (DIRC) of BaBar
The DIRC (acronym for Detection of Internally Reflected Cherenkov (light)) is a new type of Cherenkov ring imaging detector based on total internal reflection that is used for the first time in the BaBar detector at PEP-II ring of SLAC. The Cherenkov radiators are long rectangular bars made of synthetic fused silica. The photon detector is a water tank equipped with an array of 10,752 conventional photomultipliers. The first year operational experience in the BaBar detector is presented using cosmic data and collision data in the energy region of the Y(4s) resonance.
Date:
April 1, 2000
Creator:
Adam, I. & Collaboration, BaBar
Object Type:
Article
System:
The UNT Digital Library