Harmonics suppression in electromagnets with application to the ALS storage ring corrector magnet design (open access)

Harmonics suppression in electromagnets with application to the ALS storage ring corrector magnet design

This memo presents an analytical development for prediction of skew harmonics in a iron core C-magnet to due arbitrarily positioned electromagnet coils. A structured approach is presented for the suppression of an arbitrary number of harmonic components to arbitrarily low values. Application of the analytical harmonic strength calculations coupled to the structured harmonic suppression approach is presented in the context of the design of the ALS storage ring corrector magnets.
Date: January 28, 1991
Creator: Schlueter, R. D.
Object Type: Report
System: The UNT Digital Library
Groundwater Monitoring Plan for the 216-A-29 Ditch (open access)

Groundwater Monitoring Plan for the 216-A-29 Ditch

This report describes the groundwater monitoring plan for the 216-A-29 ditch on the Hanford Site. This document presents a groundwater monitoring plan, under Resource Conservation and Recovery Act of 1976 (RCRA) regulatory requirements found in WAC 173-303-400, and by reference, requirements in 40 CFR 265.93 (d)(6) for the 216-A-29 Ditch (A-29 Ditch) in the Hanford Site's 200 East Area. The objectives of this monitoring plan are to determine whether any hazardous constituents are detectable in the groundwater beneath the ditch. The groundwater monitoring network described in this plan includes 10 RCRA-compliant wells to monitor the aquifer in the immediate vicinity of the A-29 Ditch. Groundwater assessment activities have been conducted at the A-29 Ditch, the result of elevated specific conductivity and total organic halogens (TOX). A groundwater assessment report (Votava 1995) found that no hazardous constituents had impacted groundwater and the site returned to interim-status indicator-parameter/detection monitoring. This plan describes the process and quality objectives for conducting the indicator-parameter program. The site will be sampled semiannually for indicator parameters including pH, specific conductance, TOX, and total organic carbon. Site-specific parameters include tritium and ICP metals. These constituents, as well as anions, alkalinity, and turbidity will be sampled annually. Groundwater elevations …
Date: January 28, 1999
Creator: Sweeney, Mark D.
Object Type: Report
System: The UNT Digital Library
[The mechanisms of hydrogen incorporation in coal liquefaction] (open access)

[The mechanisms of hydrogen incorporation in coal liquefaction]

In earlier reports we have describe d our efforts to understand the mechanism of deuterium incorporation during the thermolysis of 1,2-diphenylethane and 2,2,5,5-tetramethyl-3,4-diphenylhexane under D[sub 2] gas in a glass vessel. We have reported that in both of these cases, there is substantial deuterium incorporation. A summary of our conclusions follows: Conclusions previously reported for the 1,2-diphenylethane (DPE) system. 1. Benzyl radicals produced in the thermolysis react mainly with DPE to extract a hydrogen atom and produce undeuterated toluene. 2. The 1,2-diphenylethyl radicals produced are mainly responsible for the reaction with D[sub 2] to give D atoms. 3. D atoms then react with aromatic rings to form adduct radicals which are, at least in part, reconverted to D-substituted aromatics in termination steps. 4.2-Phenylethyl radicals react in a less discriminating manner, 1/3 to 1/2 of the events probably involving direct reaction with D[sub 2]. 5. A reasonable match to major product distribution can be accomplished using a model consisting of the set of ten reactions.
Date: January 28, 1993
Creator: Guthrie, R.
Object Type: Report
System: The UNT Digital Library
Applied technology section. Monthly report, December 1993 (open access)

Applied technology section. Monthly report, December 1993

This monthly report contains abstracts of the progress made in various projects from the applied technology section at the Savannah River Plant. Research areas include engineering modeling and simulation, applied physics, experimental thermal hydraulics, and packaging and transportation.
Date: January 28, 1994
Creator: Buckner, M. R.
Object Type: Report
System: The UNT Digital Library
Harmonics suppression in electromagnets with application to the ALS storage ring corrector magnet design (open access)

Harmonics suppression in electromagnets with application to the ALS storage ring corrector magnet design

This memo presents an analytical development for prediction of skew harmonics in a iron core C-magnet to due arbitrarily positioned electromagnet coils. A structured approach is presented for the suppression of an arbitrary number of harmonic components to arbitrarily low values. Application of the analytical harmonic strength calculations coupled to the structured harmonic suppression approach is presented in the context of the design of the ALS storage ring corrector magnets.
Date: January 28, 1991
Creator: Schlueter, R. D.
Object Type: Report
System: The UNT Digital Library
Environmental and economic assessment of discharges from Gulf of Mexico Region Oil and Gas Operations. Quarterly technical progress report, 1 October--31 December 1993 (open access)

Environmental and economic assessment of discharges from Gulf of Mexico Region Oil and Gas Operations. Quarterly technical progress report, 1 October--31 December 1993

Task 2 (Preparation of the Sampling and Analysis Plan) activities involved the incorporation of the offshore site selection process into the Sampling and Analysis Plan. Task 3 (Environmental Field Sampling and Analysis of NORM, Heavy Metals, and Organics) work included making decisions on tissue analyses and performing analyses of water and sediment samples. Task 4 (Monitoring of the Recovery of Impacted Wetland and Open Bay Produced Water Discharge Sites in Coastal Louisiana and Texas) activities involved the completion of the spring benthos samples collection on pre-termination samples at Four Isle Dome and the first post-termination samples at Delacroix Island. Task 5 (Assessment of Economic Impacts of Offshore and Coastal Discharge Requirements on Present and Future Operations in the Gum of Mexico Region) activities included continued work on development of a base case production forecast, modeling future production, and determining economic impact of treatment technologies. Task 6 (Synthesis of Gulf of Mexico Seafood Consumption and Use Patterns) work involved the completion of the fall survey season and the initiation of the survey data assembly. Task 7 (Technology Transfer Plan) activities included presentations at the Society of Environmental Toxicology and Chemistry annual meeting and Minerals Management Service Information Transfer Meeting. Task 8 …
Date: January 28, 1994
Creator: Gettleson, D. A.
Object Type: Report
System: The UNT Digital Library
A real-time emergency response workstation using a 3-D numerical model initialized with sodar (open access)

A real-time emergency response workstation using a 3-D numerical model initialized with sodar

Many emergency response dispersion modeling systems provide simple Gaussian models driven by single meteorological tower inputs to estimate the downwind consequences from accidental spills or stack releases. Complex meteorological or terrain settings demand more sophisticated resolution of the three-dimensional structure of the atmosphere to reliably calculate plume dispersion. Mountain valleys and sea breeze flows are two common examples of such settings. To address these complexities, the authors have implemented the three-dimensional diagnostic MATHEW mass-adjusted wind field and ADPIC particle-in-cell dispersion models on a workstation for use in real-time emergency response modeling. MATHEW/ADPIC have shown their utility in a variety of complex settings over the last 15 years within the Department of Energy`s Atmospheric Release Advisory Capability (ARAC) project. The models are initialized using an array of surface wind measurements from meteorological towers coupled with vertical profiles from an acoustic sounder (sodar). The workstation automatically acquires the meteorological data every 15 minutes. A source term is generated using either defaults or a real-time stack monitor. Model outputs include contoured isopleths displayed on site geography or plume densities shown over 3-D color shaded terrain. The models are automatically updated every 15 minutes to provide the emergency response manager with a continuous display …
Date: January 28, 1993
Creator: Lawver, B. S.; Sullivan, T. J. & Baskett, R. L.
Object Type: Article
System: The UNT Digital Library
First-wall heat-flux measurements during ELMing H-mode plasma (open access)

First-wall heat-flux measurements during ELMing H-mode plasma

In this report we present measurements of the diverter heat flux in DIII-D for ELMing H-mode and radiative diverter conditions. In previous work we have examined heat flux profiles in lower single-null diverted plasmas and measured the scaling of the peak heat flux with plasma current and beam power. One problem with those results was our lack of good power accounting. This situation has been improved to better than 80--90% accountability with the installation of new bolometer arrays, and the operation of the entire complement of 5 Infrared (IR) TV cameras using the DAPS (Digitizing Automated Processing System) video processing system for rapid inter-shot data analysis. We also have expanded the scope of our measurements to include a wider variety of plasma shapes (e.g., double-null diverters (DND), long and short single-null diverters (SND), and inside-limited plasmas), as well as more diverse discharge conditions. Double-null discharges are of particular interest because that shape has proven to yield the highest confinement (VH-mode) and beta of all DIII-D plasmas, so any future diverter modifications for DIII-D will have to support DND operation. In addition, the proposed TPX tokamak is being designed for double-null operation, and information on the magnitude and distribution of diverter …
Date: January 28, 1994
Creator: Lasnier, C. J.; Allen, S. L.; Hill, D. N.; Leonard, A. W. & Petrie, T. W.
Object Type: Report
System: The UNT Digital Library
Engineering development of advanced coal-fired low-emission boiler systems. Quarterly technical progress report, October--December 1993 (open access)

Engineering development of advanced coal-fired low-emission boiler systems. Quarterly technical progress report, October--December 1993

Preliminary subsystem designs were developed for a Low-Emission Boiler System. Key features of the NO{sub x} and Boiler Subsystem includes: deep staged combustion with advanced low NO{sub x} burners in a furnace arrangement designed to minimize NO{sub x} emission, advanced pulverizer design, advanced operating diagnostics and control integration of steam conditions, combustion, burner management, and sootblowing.
Date: January 28, 1994
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Encapsulation of Hazardous Wastes Into Agglomerates (open access)

Encapsulation of Hazardous Wastes Into Agglomerates

The objective of this study was to investigate the feasibility of using the cementitious properties and agglomeration characteristics of coal conversion byproducts to encapsulate and immobilize hazardous waste materials. The intention was to establish an economical way of co-utilization and co-disposal of wastes. In addition, it may aid in the eradication of air pollution problems associated with the fine-powdery nature of fly ash. Encapsulation into agglomerates is a novel approach of treating toxic waste. Although encapsulation itself is not a new concept, existing methods employ high-cost resins that render them economically unfeasible. In this investigation, the toxic waste was contained in a concrete-like matrix whereby fly ash and other cementitious waste materials were utilized. The method incorporates the principles of solidification, stabilization and agglomeration. Another aspect of the study is the evaluation of the agglomeration as possible lightweight aggregates. Since fly ash is commercially used as an aggregate, it would be interesting to study the effect of incorporating toxic wastes in the strength development of the granules. In the investigation, the fly ash self-cementation process was applied to electroplating sludges as the toxic waste. The process hoped to provide a basis for delisting of the waste as hazardous and, thereby …
Date: January 28, 1992
Creator: Guloy, Aida
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Computer animation of clouds (open access)

Computer animation of clouds

Computer animation of outdoor scenes is enhanced by realistic clouds. I will discuss several different modeling and rendering schemes for clouds, and show how they evolved in my animation work. These include transparency-textured clouds on a 2-D plane, smooth shaded or textured 3-D clouds surfaces, and 3-D volume rendering. For the volume rendering, I will present various illumination schemes, including the density emitter, single scattering, and multiple scattering models.
Date: January 28, 1994
Creator: Max, N.
Object Type: Article
System: The UNT Digital Library
2F Evaporator CP class instrumentation uncertainties evaluations (open access)

2F Evaporator CP class instrumentation uncertainties evaluations

There are two instrumentation systems in the 2F Evaporator facilities (bldg. 242-16F) that are classified as the Critical Protection (CP). They are the Evaporator Pot Temperature instrumentations and Steam Condensate Gamma Monitor. The pot instrumentation consists of two interrelated circuits sharing the same temperature sensor and transducer. They are the high alarm and interlock circuit and the recorder circuit. The gamma monitor instrumentation consists of four interrelated circuits sharing the same scintillation detector. They are the gamma alarm and interlock circuit, failure alarm and interlock circuit, condensate cesium activity recorder circuit, and condensate americium activity recorder circuit. The resulting uncertainties for the instrument circuits are tabulated. (GHH)
Date: January 28, 1994
Creator: Hwang, Edward
Object Type: Report
System: The UNT Digital Library
A novel process for methanol synthesis. Progress report, September 1, 1991--November 30, 1991 (open access)

A novel process for methanol synthesis. Progress report, September 1, 1991--November 30, 1991

A bench-scale reactor is being used to conduct studies of the conversion of synthesis gas to methanol by a novel process. In previous reports, we provided evidence for a two step reaction in series: the carbonylation of methanol to methyl formate taking place in a non-equilibrium region in the vicinity of the copper chromite surface, and the hydrogenolysis of methyl formate to methanol taking place on the surface of the copper chromite. The synergism between the two catalysts enhances the rate of methanol formation. In this quarter, we tested several copper chromites (with different surface areas and stabilizing agents) on the rate of methanol synthesis. It seems likely that pore diffusion limitations control the hydrogenolysis reaction since the rate of methanol formation is proportional to the square root of the copper chromite surface area. Elemental analyses using Inductively Coupled Plasma analysis and pore size distribution analysis of copper chromite were carried out.
Date: January 28, 1992
Creator: Tierney, J. W. & Wender, I.
Object Type: Report
System: The UNT Digital Library
2F and 2H evaporator loop evaluation closure report (open access)

2F and 2H evaporator loop evaluation closure report

As a result of the Concentrate Transfer System (CTS) tank ventilation system contamination event, a task team was formed to evaluate instrument loops associated with waste reduction equipment. During the event a conductivity probe designed to provide an alarm and initiate an interlock failed to respond to the presence of liquid. An investigation revealed that the probe had become disconnected from the loop. The daily functional check of the conductivity probe circuit only tested the circuit continuity from the ventilation unit to the control room and did not actually test the probe. To test the continuity, a test switch was used to simulate the conducting probe. Because the functional check did not test each part of the loop, the test could be satisfactorily completed even though the probe itself was inoperable. The function of the task team was to develop a list of loops and interlocks prioritized by importance and likelihood of similar failure. The team evaluated the associated loop calibration and functional test procedures to verify that they are adequate to ensure loop performance on a periodic frequency. This report documents the evaluation findings and associated actions required prior to startup of the 2F and 2H evaporators.
Date: January 28, 1994
Creator: Bates, W. F.
Object Type: Report
System: The UNT Digital Library
Study of neutron focusing at the Texas Cold Neutron Source: Progress report (open access)

Study of neutron focusing at the Texas Cold Neutron Source: Progress report

The purpose of this three year study is to develop a neutron focusing system to be used with the Texas Cold Neutron Source (TCNS) to produce an intense beam of neutrons. A prompt gamma activation analysis (PGAA) facility will also be designed, setup, and tested under this DOE grant. During the first year of the DOE grant, a new procedure was developed and used to design a focusing converging guide consisting of truncated rectangular cone sections. Detailed calculations were performed using a 3-D Monte Carlo code which the authors wrote to trace neutrons through the existing curved guide of the TCNS into the proposed converging guide. Using realistic reflectivities for Ni-Ti supermirrors, they obtained gains of 4 to 5 for the neutron flux averaged over an area of 1 x 1 cm. Two graduate students were supported by the first year of the DOE grant. Both have passed the Nuclear Engineering qualifying examination and have been admitted to candidacy for the doctoral degree at The University of Texas at Austin. Their programs of study and dissertation projects have been approved by the appropriate committees.
Date: January 28, 1993
Creator: Wehring, B. W. & Uenlue, K.
Object Type: Report
System: The UNT Digital Library
Oxidation of Coal and Coal Pyrite Mechanisms and Influence on Surface Characteristics. Technical Progress Report, [September--December 1991] (open access)

Oxidation of Coal and Coal Pyrite Mechanisms and Influence on Surface Characteristics. Technical Progress Report, [September--December 1991]

The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical coal cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the fifth quarter, wet chemical and dry oxidation tests were done on Upper Freeport coal from the Troutville {number_sign}2 Mine, Clearfield County, Pennsylvania.
Date: January 28, 1992
Creator: Doyle, F. M.
Object Type: Report
System: The UNT Digital Library
Liquid Phase Methanol LaPorte Process Development Unit: Modification Operation, and Support Studies. Task 3.6/3.7: Alternative Catalyst/Life Run (open access)

Liquid Phase Methanol LaPorte Process Development Unit: Modification Operation, and Support Studies. Task 3.6/3.7: Alternative Catalyst/Life Run

In April 1987, Air Products started the third and final contract with the US Department of Energy to develop the Liquid Phase Methanol (LPMEOH) process. One of the objectives was to identify alternative commercial catalyst(s) for the process. This objective was strategically important as we want to demonstrate that the LPMEOH process is flexible and not catalyst selection limited. Among three commercially available catalysts evaluated in the lab, the catalyst with a designation of F21/0E75-43 was the most promising candidate. The initial judging criteria included not only the intrinsic catalyst activity but also the ability to be used effectively in a slurry reactor. The catalyst was then advanced for a 40-day life test in a laboratory 300 cc autoclave. The life test result also revealed superior stability when compared with that of a standard catalyst. Consequently, the new catalyst was recommended for demonstration in the Process Development Unit (PDU) at LaPorte, Texas. This report details the methodology of testing and selecting the catalyst.
Date: January 28, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Final report: Optical design of 1.15:1 relay lens NAO=0.245 (open access)

Final report: Optical design of 1.15:1 relay lens NAO=0.245

Lawrence Livermore National Laboratory (LLNL) needs a 1.15:1 magnification relay lens that will image a CRT with fiber optics faceplate onto a CCD detector array. Optical Research Associates (ORA) designed a similar lens several years ago with a different magnification (2.5:1 see Reference 1). LLNL had the lens built, and it performed satisfactorily. Now a larger CCD is available, and LLNL needs this new design to have many features of the earlier form except for magnification. Some of these features include virtual telecentricity at both the input and output of the lens, high collection and transmission efficiency, low image distortion, and moderately high MTF modest spatial frequency in the image. A reference in this report lists the complete set of requirements and goals for an intermediate magnification, and we repeat many of them in this report. LLNL has changed the magnification requirement, because we found that the design could not meet some of the former mechanical constraints with the new goal. During the design process, we found that a lens based on previous form (double gauss derivative) was very sensitive to small errors of construction (such as element thickness and centering). We decided to try an alternate design that is …
Date: January 28, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Investigation of mineral transformations and ash deposition during staged combustion. Quarterly technical progress report, October 1, 1993--December 31, 1993 (open access)

Investigation of mineral transformations and ash deposition during staged combustion. Quarterly technical progress report, October 1, 1993--December 31, 1993

A thorough understanding of the fundamental processes which govern the mineral behavior is essential to the development of tools to predict and manage ash deposition. The purpose of the current project is to perform a fundamental study of mineral transformations and ash deposition during staged combustion of pulverized coal. Staging of combustion air is a strategy used to reduce NO{sub x} emissions from coal-fired units. It is applicable to both advanced combustion systems currently under development (e.g. HITAF) and low NO{sub x} retrofits for existing units. These low NO{sub x} combustion strategies produce fuel rich or reducing conditions in the lower furnace. Therefore, the combustion history of the coal particles is significantly changed from that experienced under normal combustion conditions. A carefully designed experimental study is needed to examine the effects of altered combustion conditions on mineral matter release, fly ash formation, particle stickiness and deposit formation. This project uses state-of-the-art analytical equipment and a well-characterized laboratory combustor to address this need. This report describes work in the initial quarter of a fundamental, three-year study of mineral transformations and ash deposition during staged combustion.
Date: January 28, 1994
Creator: Harb, J. N.
Object Type: Report
System: The UNT Digital Library
Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 5, October--December, 1993 (open access)

Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 5, October--December, 1993

During this quarter several runs directed at revealing the presence of transport limitations were conducted. Also, methanol oxidation over vanadyl pyrophosphate was studied in a series of tests that investigated the effects of pressure, temperature, and methanol:oxygen ratio. Work on the preparation of a silica supported catalyst continued and several promoted catalysts were prepared. These results are discussed in detail and plans for the coming quarter are outlined.
Date: January 28, 1994
Creator: McCormick, Robert L.; Jha, Mahesh C. & Streuber, R. D.
Object Type: Report
System: The UNT Digital Library
Linkage of anthropogenic aerosol to clouds and climate. Progress report No. 2 (open access)

Linkage of anthropogenic aerosol to clouds and climate. Progress report No. 2

This progress report describes the monitoring being done to validate a linkage of anthropogenic aerosol to clouds and climate. Equipment and findings are reported. The equipment construction called for in the original proposal has now been competed. These instruments are the high temperature processor, the data acquisition system for the direct Royco optical particle counter (OPC), and modifications to the formvar replicator. The main field effort during the past year has been the shipboard experiment SEAHUNT (Shiptrail Evolution Above High Updraft Naval Targets). There were also some laboratory and local ambient particle measurements and a surface field program on and near the California coast. The shipboard project was not anticipated in the original proposal but the laboratory and surface measurements were along the lines suggested in the original proposal.
Date: January 28, 1992
Creator: Hudson, J. G.
Object Type: Report
System: The UNT Digital Library
[The mechanisms of hydrogen incorporation in coal liquefaction]. Sixth progress report, December 31, 1992 (open access)

[The mechanisms of hydrogen incorporation in coal liquefaction]. Sixth progress report, December 31, 1992

In earlier reports we have describe d our efforts to understand the mechanism of deuterium incorporation during the thermolysis of 1,2-diphenylethane and 2,2,5,5-tetramethyl-3,4-diphenylhexane under D{sub 2} gas in a glass vessel. We have reported that in both of these cases, there is substantial deuterium incorporation. A summary of our conclusions follows: Conclusions previously reported for the 1,2-diphenylethane (DPE) system. 1. Benzyl radicals produced in the thermolysis react mainly with DPE to extract a hydrogen atom and produce undeuterated toluene. 2. The 1,2-diphenylethyl radicals produced are mainly responsible for the reaction with D{sub 2} to give D atoms. 3. D atoms then react with aromatic rings to form adduct radicals which are, at least in part, reconverted to D-substituted aromatics in termination steps. 4.2-Phenylethyl radicals react in a less discriminating manner, 1/3 to 1/2 of the events probably involving direct reaction with D{sub 2}. 5. A reasonable match to major product distribution can be accomplished using a model consisting of the set of ten reactions.
Date: January 28, 1993
Creator: Guthrie, R.
Object Type: Report
System: The UNT Digital Library
100-DR-1 radiological surveys (open access)

100-DR-1 radiological surveys

This report summarizes and documents the results of the radiological surveys conducted over the surface of the 100-DR-1 Operable Unit, Hanford Site, Richland, Washington. In addition, this report explains the survey methodology using the Ultrasonic Ranging and Data System (USRADS). The 100-DR-1 radiological survey field task consisted of two activities: characterization of the operable unit-specific background conditions and the radiological survey of the operable unit surface area. The survey methodology was based on utilization of USRADS for automated recording of the gross gamma radiation levels at or near 6 in. and at 3 ft from the surface soil. The purpose of the survey is to identify the location of unidentified subsurface radioactive material areas and any surface contamination associated with these areas. The radiological surveys were conducted using both a digital count rate meter with a NaI detector reporting in counts per minute (CPM) and a dose rate meter reporting micro-Roentgen per hour (uR) connected to a CHEMRAD Tennessee Corp. Series 2000 USRADS. The count rate meter was set for gross counting, i.e., Window ``out``. The window setting allows detection of low, intermediate, and high energy photons. The USRADS equipment is used to record the detector readings verses the location …
Date: January 28, 1994
Creator: Naiknimbalkar, N. M.
Object Type: Report
System: The UNT Digital Library
High resolution microstructural and microchemical analysis of zirconia eutectic interfaces. Progress report, July 1991--June 1992 (open access)

High resolution microstructural and microchemical analysis of zirconia eutectic interfaces. Progress report, July 1991--June 1992

The goal of the research performed here is to study and understand the nature of fine scale microchemical variation, on the order of the lattice periodicity, in ceramic oxides. To that end, during the past year, emphasis was placed on the selection of appropriate materials systems and their fabrication into samples suitable for study using advanced high resolution analytical electron microscopy (work to be performed in the coming year). The work concentrated on two materials systems.
Date: January 28, 1992
Creator: Notis, M. R.
Object Type: Report
System: The UNT Digital Library