Partner
UNT Libraries Government Documents Department
1,099
Oklahoma Historical Society
455
UNT Libraries Special Collections
122
Sterling Municipal Library
27
UNT Music Library
26
Carl Albert Congressional Research and Studies Center
16
Alvin Community College
14
UNT Libraries
13
San Antonio Public Library
12
Rice University Woodson Research Center
11
74 More
Collection
Office of Scientific & Technical Information Technical Reports
863
Texas Digital Newspaper Program
320
Jim Argo Collection
277
Oklahoma Digital Newspaper Program
158
Tocker Foundation Grant
142
Government Accountability Office Reports
124
KXAS-NBC 5 News Collection
54
Oklahoma Historical Society Photograph Collection
45
Congressional Research Service Reports
42
Texas State Publications
32
134 More
Degree Department
Degree Discipline
Degree Level
Country
Year
Month
Annual Report of the Swallow-tailed Kite in Texas: 1998
Report compiling "information sent in by the public [...regarding] sightings of the Swallow-tailed Kite (Elanoides forficatus) for 1998 in Texas, unless stated otherwise" (p. 1), including data for 277 individual sightings that has been broken down by various factors.
Date:
March 1999
Creator:
Shackelford, Clifford E. & Simons, Gael G.
Object Type:
Report
System:
The Portal to Texas History
[Antonio Gil Y'Barbo: Pioneer and Builder of Nacogdoches, TX]
Step into the remarkable world of Antonio Gil Y'Barbo, a pioneering settler whose contributions to Nacogdoches, Texas, were pivotal for both his people and the region's history. Born in 1729 at the presidio of Los Adaes, Y'Barbo's journey from the military to cattle ranching and trading shaped the destiny of the area. Discover the challenges he faced under the stringent mercantilism of the Spanish Monarchy and how he played a vital role in providing a foundation for future Anglo-American settlers in Texas. Uncover the legacy of a man who left an indelible mark on Nacogdoches and beyond.
Date:
March 1999
Creator:
Mallory, Randy
Object Type:
Photograph
System:
The UNT Digital Library
Application of the normalization data analysis technique for single specimen R-curve determination
The authors conclude that the normalization technique for single specimen R-curve and J{sub IC} determination can be very effective. Much like EPD, this technique requires some user interpretation/judgement during data analysis and may be difficult to standardize or fully automate even with strict analysis rules.
Date:
March 1, 1999
Creator:
Porr, W. C. & Mills, W. J.
Object Type:
Article
System:
The UNT Digital Library
An approach to fundamental study of beam loss minimization
The accelerator design rules involving rms matching, developed at CERN in the 1970`s, are discussed. An additional rule, for equipartitioning the beam energy among its degrees of freedom, may be added to insure an rms equilibrium conditions. If the strong stochasticity threshold is avoided, as it is in realistic accelerator designs, the dynamics is characterized by extremely long transient settling times, making the role of equipartitioning hard to explain. An approach to systematic study using the RFQ accelerator as a simulation testbed is discussed. New methods are available from recent advances in research on complexity, nonlinear dynamics, and chaos.
Date:
March 1, 1999
Creator:
Jameson, Robert A.
Object Type:
Article
System:
The UNT Digital Library
Asotin Creek Instream Habitat Alteration Projects: 1998 Habitat Evaluation Surveys.
The Asotin Creek Model Watershed Master Plan was completed 1994. The plan was developed by a landowner steering committee for the Asotin County Conservation District (ACCD), with technical support from the various Federal, State and local entities. Actions identified within the plan to improve the Asotin Creek ecosystem fall into four main categories, (1) Stream and Riparian, (2) Forestland, (3) Rangeland, and (4) Cropland. Specific actions to be carried out within the stream and in the riparian area to improve fish habitat were, (a) create more pools, (b) increase the amount of large organic debris (LOD), (c) increase the riparian buffer zone through tree planting, and (d) increase fencing to limit livestock access; additionally, the actions are intended to stabilize the river channel, reduce sediment input, and protect private property. Fish species of main concern in Asotin Creek are summer steelhead (Oncorhynchus mykiss), spring chinook (Oncorhynchus tshawytscha), and bull trout (Salvelinus confluentus). Spring chinook in Asotin Creek are considered extinct (Bumgarner et al. 1998); bull trout and summer steelhead are below historical levels and are currently as ''threatened'' under the ESA. In 1998, 16 instream habitat projects were planned by ACCD along with local landowners. The ACCD identified the need …
Date:
March 1, 1999
Creator:
Bumgarner, Joseph D.
Object Type:
Report
System:
The UNT Digital Library
Aspherical bubble dynamics and oscillation times
The cavitation bubbles common in laser medicine are rarely perfectly spherical and are often located near tissue boundaries, in vessels, etc., which introduce aspherical dynamics. Here, novel features of aspherical bubble dynamics are explored. Time-resolved experimental photographs and simulations of large aspect ratio (length:diameter {approximately}20) cylindrical bubble dynamics are presented. The experiments and calculations exhibit similar dynamics. A small high-pressure cylindrical bubble initially expands radially with hardly any axial motion. Then, after reaching its maximum volume, a cylindrical bubble collapses along its long axis with relatively little radial motion. The growth-collapse period of these very aspherical bubbles differs only sightly from twice the Rayleigh collapse time for a spherical bubble with an equivalent maximum volume. This fact justifies using the temporal interval between the acoustic signals emitted upon bubble creation and collapse to estimate the maximum bubble volume. As a result, hydrophone measurements can provide an estimate of the bubble energy even for aspherical bubbles. The prolongation of the oscillation period of bubbles near solid boundaries relative to that of isolated spherical bubbles is also discussed.
Date:
March 1, 1999
Creator:
Godwin, R.P.; Chapyak, E.J.; Noack, J. & Vogel, A.
Object Type:
Report
System:
The UNT Digital Library
An assessment of the validity of cerium oxide as a surrogate for plutonium oxide gallium removal studies
Methods for purifying plutonium metal have long been established. These methods use acid solutions to dissolve and concentrate the metal. However, these methods can produce significant mixed waste, that is, waste containing both radioactive and chemical hazards. The volume of waste produced from the aqueous purification of thousands of weapons would be expensive to treat and dispose. Therefore, a dry method of purification is highly desirable. Recently, a dry gallium removal research program commenced. Based on initial calculations, it appeared that a particular form of gallium (gallium suboxide, Ga{sub 2}O) could be evaporated from plutonium oxide in the presence of a reducing agent, such as small amounts of hydrogen dry gas within an inert environment. Initial tests using ceria-based material (as a surrogate for PuO{sub 2}) showed that thermally-induced gallium removal (TIGR) from small samples (on the order of one gram) was indeed viable. Because of the expense and difficulty of optimizing TIGR from plutonium dioxide, TIGR optimization tests using ceria have continued. This document details the relationship between the ceria surrogate tests and those conducted using plutonia.
Date:
March 1, 1999
Creator:
Kolman, D.G.; Park, Y.; Stan, M.; Hanrahan, R.J. Jr. & Butt, D.P.
Object Type:
Report
System:
The UNT Digital Library
ATOM-ECONOMICAL PATHWAYS TO METHANOL FUEL CELL FROM BIOMASS
An economical production of alcohol fuels from biomass, a feedstock low in carbon and high in water content, is of interest. At Brookhaven National Laboratory (BNL), a Liquid Phase Low Temperature (LPLT) concept is under development to improve the economics by maximizing the conversion of energy carrier atoms (C,H) into energy liquids (fuel). So far, the LPLT concept has been successfully applied to obtain highly efficient methanol synthesis. This synthesis was achieved with specifically designed soluble catalysts, at temperatures < 150 C. A subsequent study at BNL yielded a water-gas-shift (WGS) catalyst for the production of hydrogen from a feedstock of carbon monoxide and H{sub 2}O at temperatures < 120 C. With these LPLT technologies as a background, this paper extends the discussion of the LPLT concept to include methanol decomposition into 3 moles of H{sub 2} per mole of methanol. The implication of these technologies for the atom-economical pathways to methanol fuel cell from biomass is discussed.
Date:
March 1, 1999
Creator:
MAHAJAN,D. & WEGRZYN,J.E.
Object Type:
Article
System:
The UNT Digital Library
Atomic scale models of Ion implantation and dopant diffusion in silicon
We review our recent work on an atomistic approach to the development of predictive process simulation tools. First principles methods, molecular dynamics simulations, and experimental results are used to construct a database of defect and dopant energetics in Si. This is used as input for kinetic Monte Carlo simulations. C and B trapping of the Si self- interstitial is shown to help explain the enormous disparity in its measured diffusivity. Excellent agreement is found between experiments and simulations of transient enhanced diffusion following 20-80 keV B implants into Si, and with those of 50 keV Si implants into complex B-doped structures. Our simulations predict novel behavior of the time evolution of the electrically active B fraction during annealing.
Date:
March 1, 1999
Creator:
Caturla, M; Johnson, M; Lenosky, T; Sadigh, B; Theiss, S K; Zhu, J et al.
Object Type:
Report
System:
The UNT Digital Library
Atomistic studies of jogged screw dislocations in {gamma}-TiAl alloys
The behavior of jogged screw dislocations in {gamma}-TiAl alloys has been investigated with large-scale molecular dynamics (MD) simulations. The authors find a new mechanism for formation of pinning points in jogged screw dislocations. They also find that the critical height for the jogs in the {+-}[{bar 1}10] directions on the (001) plane to move nonconservatively is between 3r{sub 0} and 4r{sub 0}, where r{sub 0} is the nearest neighbor distance of aluminum atoms. Interstitials and vacancies are created during the nonconservative motions of the jogs. In addition, the formation of dislocation dipole and loops around the jogs is also observed.
Date:
March 1, 1999
Creator:
Chen, K.Y.; Li, M. & Zhou, S.J.
Object Type:
Report
System:
The UNT Digital Library
An Audit Report on Statewide Travel Practices
Report of the Texas State Auditor's Office related to the 75th Legislature's emphasis on limiting employee travel expenditures and using travel funds appropriately, resulting in a travel cap which reduced total statewide travel spending from appropriated funds.
Date:
March 1999
Creator:
Texas. Office of the State Auditor.
Object Type:
Report
System:
The Portal to Texas History
Automated CCD camera characterization. 1998 summer research program for high school juniors at the University of Rochester`s Laboratory for Laser Energetics: Student research reports
The OMEGA system uses CCD cameras for a broad range of applications. Over 100 video rate CCD cameras are used for such purposes as targeting, aligning, and monitoring areas such as the target chamber, laser bay, and viewing gallery. There are approximately 14 scientific grade CCD cameras on the system which are used to obtain precise photometric results from the laser beam as well as target diagnostics. It is very important that these scientific grade CCDs are properly characterized so that the results received from them can be evaluated appropriately. Currently characterization is a tedious process done by hand. The operator must manually operate the camera and light source simultaneously. Because more exposures means more accurate information on the camera, the characterization tests can become very length affairs. Sometimes it takes an entire day to complete just a single plot. Characterization requires the testing of many aspects of the camera`s operation. Such aspects include the following: variance vs. mean signal level--this should be proportional due to Poisson statistics of the incident photon flux; linearity--the ability of the CCD to produce signals proportional to the light it received; signal-to-noise ratio--the relative magnitude of the signal vs. the uncertainty in that signal; …
Date:
March 1, 1999
Creator:
Silbermann, J.
Object Type:
Report
System:
The UNT Digital Library
Automated nuclear material recovery and decontamination of large steel dynamic experiment containers
A key mission of the Los Alamos National Laboratory (LANL) is to reduce the global nuclear danger through stockpile stewardship efforts that ensure the safety and reliability of nuclear weapons. In support of this mission LANL performs dynamic experiments on special nuclear materials (SNM) within large steel containers. Once these experiments are complete, these containers must be processed to recover residual SNM and to decontaminate the containers to below low level waste (LLW) disposal limits which are much less restrictive for disposal purposes than transuranic (TRU) waste limits. The purpose of this paper is to describe automation efforts being developed by LANL for improving the efficiency, increasing worker safety, and reducing worker exposure during the material cleanout and recovery activities performed on these containers.
Date:
March 1, 1999
Creator:
Dennison, D. K.; Gallant, D. A.; Nelson, D. C.; Stovall, L. A. & Wedman, D. E.
Object Type:
Article
System:
The UNT Digital Library
The Automator: Intelligent Control System Monitoring
A large-scale control system may contain several hundred thousand control points which must be monitored to ensure smooth operation. Knowledge of the current state of such a system is often implicit in the values of these points and operators must be cognizant of the state while making decisions. Repetitive operators requiring human intervention lead to fatigue, which can in turn lead to mistakes. The authors propose a tool called the Automator based on a middleware software server. This tool would provide a user-configurable engine for monitoring control points. Based on the status of these control points, a specified action could be taken. The action could range from setting another control point, to triggering an alarm, to running an executable. Often the data presented by a system is meaningless without context information from other channels. Such a tool could be configured to present interpreted information based on values of other channels. Additionally, this tool could translate numerous values in a non-friendly form (such as numbers, bits, or return codes) into meaningful strings of information. Multiple instances of this server could be run, allowing individuals or groups to configure their own Automators. The configuration of the tool will be file-based. In the …
Date:
March 1, 1999
Creator:
Bickley, M.; Bryan, D.A. & White, K.S.
Object Type:
Article
System:
The UNT Digital Library
Balanced Dairying: Production, Volume 22, Number 2, March 1999
Newsletter of the Texas Agricultural Extension Service discussing topics related to raising dairy cows, dairy production, and managing dairy operations.
Date:
March 1999
Creator:
Texas Agricultural Extension Service
Object Type:
Journal/Magazine/Newsletter
System:
The Portal to Texas History
The Baytown Sun (Baytown, Tex.), Vol. 77, No. 104, Ed. 1 Monday, March 1, 1999
Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date:
March 1, 1999
Creator:
Dobbs, Gary
Object Type:
Newspaper
System:
The Portal to Texas History
Beam coupling impedance of fast stripline beam kickers
A fast stripline beam kicker is used to dynamically switch a high current electron beam between two beamlines. The transverse dipole impedance of a stripline beam kicker has been previously determined from a simple transmission line model of the structure. This model did not include effects due to the long axial slots along the structure as well as the cavities and coaxial feed transition sections at the ends of the structure. 3-D time domain simulations show that the simple transmission line model underestimates the low frequency dipole beam coupling impedance by about 20% for our structure. In addition, the end cavities and transition sections can exhibit dipole impedances not included in the transmission line model. For high current beams, these additional dipole coupling terms can provide additional beam-induced steering effects not included in the transmission line model of the structure.
Date:
March 1, 1999
Creator:
Caporaso, G.; Chen, Y. J.; Nelson, A. D. & Poole, B. R.
Object Type:
Article
System:
The UNT Digital Library
Beam optics studies for the CEBAF accelerator
Measurements of differential orbits excited by two pairs of horizontal and vertical connectors, and by a change of the energy gain for the first one of two superconducting linacs allowed one to perform on-line control of the machine optics which provided valuable information for studying optics discrepancies. Off-line analysis of the data has uncovered a number of malfunctioning hardware pieces, e.g., improperly functioning BPMs and incorrectly focusing quadrupoles. It also indicated that the dipoles have significant focusing terms, which have to be taken into account to build a predictable optics. The analysis resulted in a significantly improved optics model for the CEBAF recirculator. The new optics preserved desired lattice architecture and orthogonal tunability. The presented approach was proven very successful in minimizing required tuning time and in building a more accurate theoretical model of beam transport for the CEBAF accelerator.
Date:
March 1, 1999
Creator:
Bogacz, S. & Lebedev, V.
Object Type:
Article
System:
The UNT Digital Library
Beam-target interaction experiments for Bremsstrahlung converter applications
The authors are investigating the possible adverse effects of (1) backstreaming ion emission from the Bremsstrahlung converter target and (2) the interaction of the resultant plasma with the electron beam during subsequent pulses for multi-pulse radiography facilities. These effects would primarily manifest themselves in a static focusing system as a rapidly varying x-ray spot. To study these effects, they are conducting beam-target interaction experiments on the ETA-II accelerator (a 6.0 MeV, 2.5 kA, 70 ns FWHM pulsed, electron accelerator). They are measuring spot dynamics and characterizing the resultant plasma for various configurations. Thus far, their experiments show that the first effect is not strongly present when the beam initially interacts with the target. Electron beam pulses delivered to the target after formation of a plasma are strongly affected. They have also performed initial experiments to determine the effect of the beam propagating through the plasma. This data shows that the head of the beam is relatively robust, but that backstreaming ions from the plasma can still manifest itself as a dynamic focus toward the tail of the beam. They report on the details of the experimental work to suppress these effects.
Date:
March 1, 1999
Creator:
Buckles, R.; Caparaso, G.; Chen, Y. J.; Crist, C.; Falabella, S.; Houck, T. et al.
Object Type:
Article
System:
The UNT Digital Library
Best Practices and Guidelines for Effectively Using a Contract Workforce
Report of the Texas State Auditor's Office related to providing state entities guidelines to consider for effectively using and properly managing their contract workforce.
Date:
March 1999
Creator:
Texas. Office of the State Auditor.
Object Type:
Report
System:
The Portal to Texas History
Big Bayou Creek and Little Bayou Creek Watershed Monitoring Program
Biological monitoring of Little Bayou and Big Bayou creeks, which border the Paducah Site, has been conducted since 1987. Biological monitoring was conducted by University of Kentucky from 1987 to 1991 and by staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) from 1991 through March 1999. In March 1998, renewed Kentucky Pollutant Discharge Elimination System (KPDES) permits were issued to the US Department of Energy (DOE) and US Enrichment Corporation. The renewed DOE permit requires that a watershed monitoring program be developed for the Paducah Site within 90 days of the effective date of the renewed permit. This plan outlines the sampling and analysis that will be conducted for the watershed monitoring program. The objectives of the watershed monitoring are to (1) determine whether discharges from the Paducah Site and the Solid Waste Management Units (SWMUs) associated with the Paducah Site are adversely affecting instream fauna, (2) assess the ecological health of Little Bayou and Big Bayou creeks, (3) assess the degree to which abatement actions ecologically benefit Big Bayou Creek and Little Bayou Creek, (4) provide guidance for remediation, (5) provide an evaluation of changes in potential human health concerns, and (6) provide data …
Date:
March 1, 1999
Creator:
Kszos, L. A.; Peterson, M. J.; Ryon & Smith, J. G.
Object Type:
Report
System:
The UNT Digital Library
Biodegradation of high explosives on granular activated carbon [GAC]: Enhanced desorption of high explosives from GAC -- Batch studies
Adsorption to GAC is an effective method for removing high explosives (HE) compounds from water, but no permanent treatment is achieved. Bioregeneration, which treats adsorbed contaminants by desorption and biodegradation, is being developed as a method for reducing GAC usage rates and permanently degrading RDX and HMX. Because desorption is often the limiting mass transfer mechanism in bioregeneration systems, several methods for increasing the rate and extent of desorption of RDX and HMX are being studied. These include use of cosolvents (methanol and ethanol), surfactants (both anionic and nonionic), and {beta}- and {gamma}-cyclodextrins. Batch experiments to characterize the desorption of these HEs from GAC have been completed using Northwestern LB-830, the GAC being used at Pantex. Over a total of 11 days of desorption, about 3% of the adsorbed RDX was desorbed from the GAC using buffered water as the desorption fluid. In comparison, about 96% of the RDX was extracted from the GAC by acetonitrile over the same desorption period. Ethanol and methanol were both effective in desorbing RDX and HMX; higher alcohol concentrations were able to desorb more HE from the GAC. Surfactants varied widely in their abilities to enhance desorption of HEs. The most effective surfactant that …
Date:
March 1, 1999
Creator:
Morley, M. C. & Speitel, G. E., Jr.
Object Type:
Report
System:
The UNT Digital Library
Bioenergetic and physiological studies of hyperthermophilic archaea. Final report
This project focuses on physiological and bioenergetic characteristics of two representative hyperthermophilic archaea: Thermococcus litoralis (T{sub opt} 88 C) and Pyrococcus furiosus (T{sub opt} 98 C). Both are obligately anaerobic heterotrophs which grow in the presence or absence of reducible sulfur compounds. T. litoralis was studied in relation to information previously developed for P. furiosus: effect of sulfur reduction on bioenergetics, preferred fermentation patterns, tungsten requirement, etc. A defined medium was developed for T. litoralis consisting of amino acids, vitamins and nucleotides. This serves as the basis for continuous culture studies probing metabolic response to media changes. P. furiosus and T. litoralis have also been found to produce a polysaccharide in the presence of maltose and yeast extract. The composition and chemical structure of this polysaccharide was investigated as well as the metabolic motivation for its production. A novel and, perhaps, primitive intracellular proteolytic complex (previously designated as protease S66) in P. furiosus was isolated and the gene encoding the subunit of the complex was cloned, sequenced and the protease expressed in active form in Eschericia coli. Among other issues, the role of this complex in protein turnover and stress response was examined in the context of this organism in …
Date:
March 1, 1999
Creator:
Kelly, R. M.
Object Type:
Report
System:
The UNT Digital Library
Biomedical engineering research at DOE national labs
Biomedical Engineering is the application of principles of physics, chemistry, nd engineering to problems of human health. The National Laboratories of the U.S. Department of Energy have been leaders in this scientific field since 1947. This inventory of their biomedical engineering projects was compiled in January 1999.
Date:
March 1, 1999
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library