Summary of computational support and general documentation for computer code (GENTREE) used in Office of Nuclear Waste Isolation Pilot Salt Site Selection Project (open access)

Summary of computational support and general documentation for computer code (GENTREE) used in Office of Nuclear Waste Isolation Pilot Salt Site Selection Project

A Decision Tree Computer Model was adapted for the purposes of a Pilot Salt Site Selection Project conducted by the Office of Nuclear Waste Isolation (ONWI). A deterministic computer model was developed to structure the site selection problem with submodels reflecting the five major outcome categories (Cost, Safety, Delay, Environment, Community Impact) to be evaluated in the decision process. Time-saving modifications were made in the tree code as part of the effort. In addition, format changes allowed retention of information items which are valuable in directing future research and in isolation of key variabilities in the Site Selection Decision Model. The deterministic code was linked to the modified tree code and the entire program was transferred to the ONWI-VAX computer for future use by the ONWI project.
Date: December 6, 1983
Creator: Beatty, J.A.; Younker, J.L.; Rousseau, W.F. & Elayat, H.A.
Object Type: Report
System: The UNT Digital Library
Waste management strategy for nuclear fusion power systems from a regulatory perspective (open access)

Waste management strategy for nuclear fusion power systems from a regulatory perspective

A waste management strategy for future nuclear fusion power systems is developed using existing regulatory methodology. The first step is the development of a reference fuel cycle. Next, the waste streams from such a facility are identified. Then a waste management system is defined to safely handle and dispose of these wastes. The future regulator must identify the decisions necessary to establish waste management performance criteria. The data base and methodologies necessary to make these decisions must then be developed. Safe management of nuclear fusion wastes is not only a technological challenge, but encompasses significant social, political, and ethical questions as well.
Date: December 6, 1977
Creator: Heckman, R.A.
Object Type: Article
System: The UNT Digital Library
Pressure drop considerations of a lithium cooled fusion breeder tokamak reactor blanket (open access)

Pressure drop considerations of a lithium cooled fusion breeder tokamak reactor blanket

Liquid lithium was selected as one of the coolants for the 1983 fusion breeder blanket used on the magnetically confined tokamak fusion reactor, and as a result, the thermal-hydraulic calculations were dominated by magnetohydrodynamic (MHD) considerations. The applicable sets of MHD equations for the engineering thermal-hydraulic design were reviewed and compared. Special attention was given to the MHD calculations for the fertile material zone, a packed bed of composite beryllium and thorium balls, since this region can dominate the thermal-hydraulic behavior of this blanket module. To keep the pressure drops acceptable, fertile fuel balls were omitted in the inboard blanket.
Date: December 6, 1983
Creator: Wong, C. P. C.
Object Type: Report
System: The UNT Digital Library
Physics at the Planck scale (open access)

Physics at the Planck scale

Effective supergravity theories suggested by superstrings can be explored to determine their potential for successfully describing both observed physics at zero temperature and an inflationary cosmology. An important ingredient in this study is the dynamics of gaugino condensation, which has been the subject of recent activity. 33 refs., 2 figs.
Date: December 6, 1990
Creator: Gaillard, M.K. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Physics)
Object Type: Article
System: The UNT Digital Library
Damage history of Argus, a 4TW Nd-glass system (open access)

Damage history of Argus, a 4TW Nd-glass system

Argus is a twin beam, 20 cm output aperture, Nd:glass laser system that has delivered 4TW to a laser fusion target. This performance is based on the concepts that multiple spatial filtering can prevent beam fill factors. Damage to optics due to self focusing and filamentation does not occur on Argus. The only form of damage is induced by broadband radiation from xenon flashlamps interacting with contaminants on or in the Nd:glass. The severity of damage is measured by the fraction of the beam obscured by the damage sites. This averages 0.1% per surface or 0.75% per arm. The amount of damage does not appear to be strongly related to the number of amplifier firings and generally occurs during the first few firings.
Date: December 6, 1977
Creator: Stowers, I.F. & Patton, H.G.
Object Type: Article
System: The UNT Digital Library
BOA, Beam Optics Analyzer A Particle-In-Cell Code (open access)

BOA, Beam Optics Analyzer A Particle-In-Cell Code

The program was tasked with implementing time dependent analysis of charges particles into an existing finite element code with adaptive meshing, called Beam Optics Analyzer (BOA). BOA was initially funded by a DOE Phase II program to use the finite element method with adaptive meshing to track particles in unstructured meshes. It uses modern programming techniques, state-of-the-art data structures, so that new methods, features and capabilities are easily added and maintained. This Phase II program was funded to implement plasma simulations in BOA and extend its capabilities to model thermal electrons, secondary emissions, self magnetic field and implement a more comprehensive post-processing and feature-rich GUI. The program was successful in implementing thermal electrons, secondary emissions, and self magnetic field calculations. The BOA GUI was also upgraded significantly, and CCR is receiving interest from the microwave tube and semiconductor equipment industry for the code. Implementation of PIC analysis was partially successful. Computational resource requirements for modeling more than 2000 particles begin to exceed the capability of most readily available computers. Modern plasma analysis typically requires modeling of approximately 2 million particles or more. The problem is that tracking many particles in an unstructured mesh that is adapting becomes inefficient. In particular …
Date: December 6, 2007
Creator: Bui, Thuc
Object Type: Report
System: The UNT Digital Library
Butt Joint Tool Commissioning (open access)

Butt Joint Tool Commissioning

ITER Central Solenoid uses butt joints for connecting the pancakes in the CS module. The principles of the butt joining of the CICC were developed by the JAPT during CSMC project. The difference between the CSMC butt joint and the CS butt joint is that the CS butt joint is an in-line joint, while the CSMC is a double joint through a hairpin jumper. The CS butt joint has to carry the hoop load. The straight length of the joint is only 320 mm, and the vacuum chamber around the joint has to have a split in the clamp shell. These requirements are challenging. Fig.1 presents a CSMC joint, and Fig.2 shows a CS butt joint. The butt joint procedure was verified and demonstrated. The tool is capable of achieving all specified parameters. The vacuum in the end was a little higher than the target, which is not critical and readily correctable. We consider, tentatively that the procedure is established. Unexpectedly, we discover significant temperature nonuniformity in the joint cross section, which is not formally a violation of the specs, but is a point of concern. All testing parameters are recorded for QA purposes. We plan to modify the butt …
Date: December 6, 2007
Creator: Martovetsky, N. N.
Object Type: Report
System: The UNT Digital Library
Visualization of Scalar Adaptive Mesh Refinement Data (open access)

Visualization of Scalar Adaptive Mesh Refinement Data

Adaptive Mesh Refinement (AMR) is a highly effective computation method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations, which must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR grids as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR scalar data visualization research.
Date: December 6, 2007
Creator: VACET; Weber, Gunther; Weber, Gunther H.; Beckner, Vince E.; Childs, Hank; Ligocki, Terry J. et al.
Object Type: Article
System: The UNT Digital Library
A Review of the IAEA Vulnerability Assessment Level Scheme: Applicabiliy to DTRA and DOE Programs in the FSU (open access)

A Review of the IAEA Vulnerability Assessment Level Scheme: Applicabiliy to DTRA and DOE Programs in the FSU

The International Atomic Energy Agency (IAEA) plans to use the Common Criteria, as the tool for developing graded and measurable evaluation criteria for information technology (IT) in safeguards systems in facilities subject to IAEA inspection. In their draft paper [ITSECSES] the IAEA defines a three-tiered Vulnerability Assessment Level (VAL) scheme. Each increased VAL level (1-3) defines additional and more stringent security and security-related requirements for the system developer, the system evaluator (assessor or authenticator), and for the IAEA. When all parties meet all requirements for a particular VAL level, IAEA has a measurable degree of confidence in the secure and proper operation of an IT system.
Date: December 6, 2001
Creator: Devaney, Mike M.; Hansen, Randy R.; Kouzes, Richard T. & Melton, Ronald B.
Object Type: Report
System: The UNT Digital Library
Physics division annual report 1999 (open access)

Physics division annual report 1999

This report summarizes the research performed in the past year in the Argonne Physics Division. The Division's programs include operation of ATLAS as a national heavy-ion user facility, nuclear structure and reaction research with beams of heavy ions, accelerator research and development especially in superconducting radio frequency technology, nuclear theory and medium energy nuclear physics. The Division took significant strides forward in its science and its initiatives for the future in the past year. Major progress was made in developing the concept and the technology for the future advanced facility of beams of short-lived nuclei, the Rare Isotope Accelerator. The scientific program capitalized on important instrumentation initiatives with key advances in nuclear science. In 1999, the nuclear science community adopted the Argonne concept for a multi-beam superconducting linear accelerator driver as the design of choice for the next major facility in the field a Rare Isotope Accelerator (WA) as recommended by the Nuclear Science Advisory Committee's 1996 Long Range Plan. Argonne has made significant R&D progress on almost all aspects of the design concept including the fast gas catcher (to allow fast fragmentation beams to be stopped and reaccelerated) that in large part defined the RIA concept the superconducting rf …
Date: December 6, 2000
Creator: Thayer, K., ed. & Physics
Object Type: Report
System: The UNT Digital Library
A Temperature-Profile Method for Estimating Flow Processes inGeologic Heat Pipes (open access)

A Temperature-Profile Method for Estimating Flow Processes inGeologic Heat Pipes

Above-boiling temperature conditions, as encountered, forexample, in geothermal reservoirs and in geologic repositories for thestorage of heat-producing nuclear wastes, may give rise to stronglyaltered liquid and gas flow processes in porous subsurface environments.The magnitude of such flow perturbation is extremely hard to measure inthe field. We therefore propose a simple temperature-profile method thatuses high-resolution temperature data for deriving such information. Theenergy that is transmitted with the vapor and water flow creates a nearlyisothermal zone maintained at about the boiling temperature, referred toas a heat pipe. Characteristic features of measured temperature profiles,such as the differences in the gradients inside and outside of the heatpipe regions, are used to derive the approximate magnitude of the liquidand gas fluxes in the subsurface, for both steady-state and transientconditions.
Date: December 6, 2004
Creator: Birkholzer, Jens T.
Object Type: Article
System: The UNT Digital Library
Comparison of AEO 2007 Natural Gas Price Forecast to NYMEX FuturesPrices (open access)

Comparison of AEO 2007 Natural Gas Price Forecast to NYMEX FuturesPrices

On December 5, 2006, the reference case projections from 'Annual Energy Outlook 2007' (AEO 2007) were posted on the Energy Information Administration's (EIA) web site. We at LBNL have, in the past, compared the EIA's reference case long-term natural gas price forecasts from the AEO series to contemporaneous natural gas prices that can be locked in through the forward market, with the goal of better understanding fuel price risk and the role that renewables play in mitigating such risk (see, for example, http://eetd.lbl.gov/ea/EMS/reports/53587.pdf or http://eetd.lbl.gov/ea/ems/reports/54751.pdf). As such, we were curious to see how the latest AEO gas price forecast compares to the NYMEX natural gas futures strip. This brief memo presents our findings. As a refresher, our past work in this area has found that over the past six years, forward natural gas contracts (with prices that can be locked in--e.g., gas futures, swaps, and physical supply) have traded at a premium relative to contemporaneous long-term reference case gas price forecasts from the EIA. As such, we have concluded that, over the past six years at least, levelized cost comparisons of fixed-price renewable generation with variable-price gas-fired generation that have been based on AEO natural gas price forecasts (rather than …
Date: December 6, 2006
Creator: Bolinger, Mark & Wiser, Ryan
Object Type: Report
System: The UNT Digital Library
Modeling An atmospheric Release As An Area Source In Support Of Waste Disposal At The Savannah River Site (open access)

Modeling An atmospheric Release As An Area Source In Support Of Waste Disposal At The Savannah River Site

None
Date: December 6, 2005
Creator: SIMPKINS, ALI
Object Type: Article
System: The UNT Digital Library
Evaluating Cumulative Ecosystem Response to Restoration Projects in the Columbia River Estuary, Annual Report 2006 (open access)

Evaluating Cumulative Ecosystem Response to Restoration Projects in the Columbia River Estuary, Annual Report 2006

This report is the third annual report of a six-year project to evaluate the cumulative effects of habitat restoration action in the Columbia River Estuary (CRE). The project is being conducted for the U.S. Army Corps of Engineers (Corps) by the Marine Sciences Laboratory of the Pacific Northwest National Laboratory, the Pt. Adams Biological Field Station of the National Marine Fisheries Service, and the Columbia River Estuary Study Taskforce. Measurement of the cumulative effects of ecological restoration projects in the Columbia River estuary is a formidable task because of the size and complexity of the estuarine landscape and the meta-populations of salmonids in the Columbia River basin. Despite the challenges presented by this system, developing and implementing appropriate indicators and methods to measure cumulative effects is the best way to enable estuary managers to track the overall effectiveness of investments in estuarine restoration projects. This project is developing methods to quantify the cumulative effects of multiple restoration activities in the CRE. The overall objectives of the 2006 study were to continue to develop techniques to assess cumulative effects, refine the standard monitoring protocols, and initiate development of an adaptive management system for Corps of Engineers’ habitat restoration monitoring efforts in …
Date: December 6, 2007
Creator: Johnson, Gary E.; Borde, Amy B.; Dawley, Earl; Diefenderfer, Heida L.; Ebberts, Blaine D.; Putman, Douglas A. et al.
Object Type: Report
System: The UNT Digital Library
Application of exterior complex scaling to positron-hydrogencollisions including rearrangement (open access)

Application of exterior complex scaling to positron-hydrogencollisions including rearrangement

The first application of an exterior complex scaling method to an atomic scattering problem with distinct rearrangement channels is reported. Calculations are performed for positron-hydrogen collisions in an s-wave model employing an electron-positron potential of V{sub 12} = -(8+(r{sub 1}-r{sub 2}){sup 2}){sup 1/2}, using the time-independent propagating exterior complex scaling (PECS) method. This potential has the correct long-range Coulomb tail of the full problem and the results demonstrate that ECS-based methods can accurately calculate scattering, ionization and positronium formation cross sections in this three-body rearrangement collision.
Date: December 6, 2007
Creator: Bartlett, Philip L.; Stelbovics, Andris T.; Rescigno, Thomas N. & McCurdy, C. William
Object Type: Article
System: The UNT Digital Library
Effect of Twist Pitch in the Strands on the Saturation and Losses in the Nb3Sn Strands for the ITER TF CICC (open access)

Effect of Twist Pitch in the Strands on the Saturation and Losses in the Nb3Sn Strands for the ITER TF CICC

ITER TF coils will see a significant longitudinal magnetic field in the event of the plasma disruption. This abrupt change of magnetic fields results in the appearance of an additional electrical field in the strands. The mechanism of this electrical field is the induced currents that expel the flux from the strands. This effect was known since the late 1970's [1-3] and most of the details necessary for the analyses given in this report are presented in [4]. Let's assume for simplicity a zero transport current in the strand. When a longitudinal pulsed field is applied, the outer filaments will carry an induced current repelling the change of flux. The current density of this current is 'critical' in the simplification of Bean's critical state model, where superconducting transition is represented as j=j{sub c} at any non-zero electrical field and zero where the electrical field has not penetrated. In reality, since the current density is roughly logarithmic with the electrical field, E=E{sub c}*exp[(j-j{sub c})/jo], Bean's model is just a simplification, and current density is slightly nonuniform in the outer filament and more so for the interior strands. The inner portion of the filaments will carry a current of the opposite sign. …
Date: December 6, 2007
Creator: Martovetsky, N. N.
Object Type: Report
System: The UNT Digital Library
IEC International Standards Under Development For Radiation-Generating Devices (open access)

IEC International Standards Under Development For Radiation-Generating Devices

The International Electrotechnical Commission (IEC) is the leading and oldest global organization with over 100 years history of developing and publishing international standards for all electrical, electronic and related technologies, including radiation detection instrumentation. Subcommittee 45B 'Radiation Protection Instrumentation' of the IEC has recently started the development of two standards on radiation-generating devices. IEC 62463 'Radiation protection instrumentation--X-ray Systems for the Screening of Persons for Security and the Carrying of Illicit Items' is applicable to X-ray systems designed for screening people to detect if they are carrying objects such as weapons, explosives, chemical and biological agents and other concealed items that could be used for criminal purposes, e.g. terrorist use, drug smuggling, etc. IEC 62523 'Radiation protection instrumentation--Cargo/Vehicle radiographic inspection systems' applies to cargo/vehicle imaging inspection systems using accelerator produced X-ray or gamma radiation to obtain images of the screened objects (e.g. cargo containers, transport and passenger vehicles and railroad cars). The objective of both standards is to specify standard requirements and general characteristics and test procedures, as well as, radiation, electrical, environmental, mechanical, and safety requirements and to provide examples of acceptable methods to test these requirements. In particular the standards address the design requirements as they relate to …
Date: December 6, 2007
Creator: Voytchev, M; Radev, R; Chiaro, P; Thomson, I; Dray, C & Li, J
Object Type: Article
System: The UNT Digital Library
Final Hazard Categorization for the Remediation of the 118-D-1, 118-D-2, 118-D-3, 118-H-1, 118-H-2, and 118-H-3 Solid Waste Burial Grounds (open access)

Final Hazard Categorization for the Remediation of the 118-D-1, 118-D-2, 118-D-3, 118-H-1, 118-H-2, and 118-H-3 Solid Waste Burial Grounds

This report presents the final hazard categorization (FHC) for the remediation of the 118-D-1, 118-D-2, and 118-D-3 Burial Grounds located within the 100-D/DR Area of the Hanford Site and the 118-H-1, 118-H-2, and 118-H-3 Burial Grounds located within the 100-H Area of the Hanford Site.
Date: December 6, 2006
Creator: Rodovsky, T. J.
Object Type: Report
System: The UNT Digital Library
Temperature dependent evolution of the electronic and local atomic structure in the cubic colossal magnetoresistive manganite La1-xSrxMnO3 (open access)

Temperature dependent evolution of the electronic and local atomic structure in the cubic colossal magnetoresistive manganite La1-xSrxMnO3

We have studied the temperature-dependent evolution of the electronic and local atomic structure in the cubic colossal magnetoresistive manganite La{sub 1-x}Sr{sub x}MnO{sub 3} (x= 0.3-0.4) with core and valence level photoemission (PE), x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES), resonant inelastic x-ray scattering (RIXS), extended x-ray absorption fine structure (EXAFS) spectroscopy and magnetometry. As the temperature is varied across the Curie temperature T{sub c}, our PE experiments reveal a dramatic change of the electronic structure involving an increase in the Mn spin moment from {approx} 3 {micro}B to {approx} 4 {micro}B, and a modification of the local chemical environment of the other constituent atoms indicative of electron localization on the Mn atom. These effects are reversible and exhibit a slow-timescale {approx}200 K-wide hysteresis centered at T{sub c}. Based upon the probing depths accessed in our PE measurements, these effects seem to survive for at least 35-50 {angstrom} inward from the surface, while other consistent signatures for this modification of the electronic structure are revealed by more bulk sensitive spectroscopies like XAS and XES/RIXS. We interpret these effects as spectroscopic fingerprints for polaron formation, consistent with the presence of local Jahn-Teller distortions of the MnO{sub 6} octahedra around the Mn …
Date: December 6, 2007
Creator: Arenholz, Elke; Mannella, N.; Booth, C. H.; Rosenhahn, A.; Sell, B. C.; Nambu, A. et al.
Object Type: Article
System: The UNT Digital Library
Indiana Humanities Council Request for the Indianapolis Energy Conversion Inst. For Phase I of the Indianapolis Energy Conservation Res Initiative also called the smartDESKTOP Initiative (open access)

Indiana Humanities Council Request for the Indianapolis Energy Conversion Inst. For Phase I of the Indianapolis Energy Conservation Res Initiative also called the smartDESKTOP Initiative

The smartDESKTOP Initiative at the Indiana Humanities Council received critical support in building and delivering a “digital desktop” for Indiana educators through the Department of Energy Grant—DE-FG02-06ER64282. During the project period September 2006 through October of 2007, the number of Indiana educators with accounts on the smartDESKTOP more than tripled from under 2,000 to more than 7,000 accounts. An external review of the project conducted for the purposes of understanding the impact of the service in Indiana schools revealed that the majority of respondents felt that using the smartDESKTOP did reduce the time they spent managing paper. The same study revealed the challenges of implementing a digital desktop meant to help teachers leverage technology to improve their teaching and ultimately student learning. The most significant outcome of this project is that the Indiana Department of Education expressed interest in assuming responsibility for sustaining this project. The transition of the smartDESKTOP to the Indiana Department of Education was effective on November 1, 2007.
Date: December 6, 2007
Creator: Keller, John B.
Object Type: Report
System: The UNT Digital Library
The winds of Fermilab (open access)

The winds of Fermilab

The drought of 1988 caused the operations group to become concerned about the rate of evaporation from the Main Ring cooling ponds. They needed a way to data-log windspeed and direction. They had an old broken Heathkit weather station. The anemometer and windvane were salvaged and repaired. An interface to two MADC channels on the PBAR CAMAC link was built on an old piece of CAMAC card with salvaged parts. The project cost nothing. It has been in service since January 1989.
Date: December 6, 1990
Creator: Tomlin, R.
Object Type: Report
System: The UNT Digital Library
Microbial field pilot study (open access)

Microbial field pilot study

The objective of this project is to perform a microbial enhanced oil recovery field pilot test in the Southeast Vassar Vertz Sand Unit (SEVVSU) in Payne County, Oklahoma. Indigenous, anaerobic, nitrate-reducing bacteria will be stimulated to selectively plug flow paths which have been preferentially swept by a prior waterflood. This will force future flood water to invade bypassed regions of the reservoir and increase sweep efficiency. During this quarter an additional tracer study was performed in the field to determine pre-treatment flow paths and the first nutrients were injected. 2 figs.
Date: December 6, 1991
Creator: Knapp, R.M.; McInerney, M.J. & Menzie, D.E.
Object Type: Report
System: The UNT Digital Library
Jet energy resolution of the SDC detector (open access)

Jet energy resolution of the SDC detector

We have answered the PAC question ( Demonstrate the jet energy resolution of your proposed detector by studying decays Z {yields} jet + jet and Z{prime} {yields} jet + jet, M{sub Z{prime}} = 1 TeV.'') using a general program called SSCSIM. This program is a tool for investigating simple questions involving the relations between detector parameters and physics capabilities of a detector. A different package called ANLSIM developed by our colleagues at Argonne has also been used to answer this question. The results as expected are very similar. In this note we will try to document our procedures. Our tentative conclusion from this study is that physics induced effects, out-of-cone fluctuations and underlying event fluctuations, dominate the resolution. Pushing the detector performance to the limits of technology improves the effective resolution by at most 20%. 20 refs., 6 figs., 5 tabs.
Date: December 6, 1990
Creator: Para, A.; Beretvas, A.; Denisenko, K.; Denisenko, N.; Green, D.; Yeh, G.P. (Fermi National Accelerator Lab., Batavia, IL (USA)) et al.
Object Type: Report
System: The UNT Digital Library
The entropy in supernova explosions (open access)

The entropy in supernova explosions

The explosion of a supernova forms because of the collapse to a neutron star. In addition an explosion requires that a region of relatively high entropy be in contact with the neutron star and persisting for a relatively protracted period of time. The high entropy region ensures that the maximum temperature in contact with the neutron star and in hydrostatic equilibrium is less than some maximum. This temperature must be low enough such that neutrino emission cooling is small, otherwise the equilibrium atmosphere will collapse adding a large accretion mass to the neutron star. A so-called normal explosion shock that must reverse the accretion flow corresponding to a typical stellar collapse must have sufficient strength or pressure to reverse this flow and eject the matter with 10{sup 51} ergs for a typical type II supernova. Surprisingly the matter behind such a shock wave has a relatively low entropy low enough such that neutrino cooling would be orders of magnitude faster than the expansion rate. The resulting accretion low would be inside the Bondi radius and result in free-fall accretion inside the expanding rarefaction wave. The accreted mass or reimplosion mass unless stopped by a high entropy bubble could than exceed …
Date: December 6, 1990
Creator: Colgate, S. A.
Object Type: Article
System: The UNT Digital Library