Resource Type

Overview of the Flammability of Gases Generated in Hanford Waste Tanks (open access)

Overview of the Flammability of Gases Generated in Hanford Waste Tanks

This report presents an overview of what is known about the flammability of the gases generated and retained in Hanford waste tanks in terms of the gas composition, the flammability and detonability limits of the gas constituents, and the availability of ignition sources. The intrinsic flammability (or nonflammability) of waste gas mixtures is one major determinant of whether a flammable region develops in the tank headspace; other factors are the rate, surface area, volume of the release, and the tank ventilation rate, which are not covered in this report.
Date: July 21, 2000
Creator: Mahoney, L. A.; Huckaby, J. L.; Bryan, S. A. & Johnson, G. D.
System: The UNT Digital Library
High Shock, High Frequency Characteristics of a Mechanical Isolator for a Piezoresistive Accelerometer, the ENDEVCO 7270AM6* (open access)

High Shock, High Frequency Characteristics of a Mechanical Isolator for a Piezoresistive Accelerometer, the ENDEVCO 7270AM6*

A mechanical isolator has been developed for a piezoresistive accelerometer. The purpose of the isolator is to mitigate high frequency shocks before they reach the accelerometer because the high frequency shocks may cause the accelerometer to resonate. Since the accelerometer is undamped, it often breaks when it resonates. The mechanical isolator was developed in response to impact test requirements for a variety of structures at Sandia National Laboratories (SNL). An Extended Technical Assistance Program (ETAP) with the accelerometer manufacturer has resulted in a commercial mechanically isolated accelerometer that is available to the general public, the ENDEVCO 7270AM6*, for three shock acceleration ranges of 6,000 g, 20,000 g, and 60,000 g. The in-axis response shown in this report has acceptable frequency domain performance from DC to 10 kHz and 10(XO)over a temperature range of {minus}65 F to +185 F. Comparisons with other isolated accelerometers show that the ENDEVCO 7270AM6 has ten times the bandwidth of any other commercial isolator. ENDEVCO 7270AM6 cross-axis response is shown in this report.
Date: July 1, 2000
Creator: Bateman, Vesta I.; Brown, Frederick A. & Nusser, Michael A.
System: The UNT Digital Library
UNFINISHED BUSINESS: The Economics of The Kyoto Protocol (open access)

UNFINISHED BUSINESS: The Economics of The Kyoto Protocol

The Kyoto Protocol to the Framework Convention on Climate Change (FCCC) was completed on the morning of December 11, 1997, following over two years of negotiations. The product of these deliberations is a complex and incomplete document knitting together the diversity of interests and perspectives represented by the more than 150 delegations. Because the document is complex, its implications are not immediately obvious. If it enters into force, the Kyoto Protocol will have far-reaching implications for all nations--both nations with obligations under the Protocol and those without obligations. National energy systems, and the world's energy system, could be forever changed. In this paper the authors develop an assessment of the energy and economic implications of achieving the goals of the Kyoto Protocol. They find that many of the details of the Protocol that remain to be worked out introduce critical uncertainties affecting the cost of compliance. There are also a variety of uncertainties that further complicate the analysis. These include future non-CO{sub 2} greenhouse gas emissions and the cost of their mitigation. Other uncertainties include the resolution of negotiations to establish rules for determining and allocating land-use emissions rights, mechanisms for Annex 1 trading, and participation by non-Annex 1 members …
Date: July 6, 2000
Creator: Edmonds, J. A.; MacCracken, C. N.; Sands, R. D. & Kim, S. H.
System: The UNT Digital Library
THE PLASMA FLUIDIZED BED. (open access)

THE PLASMA FLUIDIZED BED.

None
Date: July 18, 2000
Creator: Currier, Robert P.; Trkula, Mitchell & Snyder, Hans R.
System: The UNT Digital Library
Second Quarter Hanford Seismic Report for Fiscal Year 2000 (open access)

Second Quarter Hanford Seismic Report for Fiscal Year 2000

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the US Department of Energy and its contractors. Hanford Seismic Monitoring also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 42 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. The HSN uses 21 sites and the EWRN uses 36 sites; both networks share 16 sites. The networks have 46 combined data channels because Gable Butte and Frenchman Hills East are three-component sites. The reconfiguration of the telemetry and recording systems was completed during the first quarter. All leased telephone lines have been eliminated and radio telemetry is now used exclusively. For the HSN, there were …
Date: July 17, 2000
Creator: Hartshorn, D. C.; Reidel, S. P. & Rohay, A. C.
System: The UNT Digital Library
Stability and transport in compact quasi-axisymmetric stellarators (open access)

Stability and transport in compact quasi-axisymmetric stellarators

The potential performance and flexibility of a compact, quasi-axisymmetric (QAS) stellarator design, has been addressed by studying the effects of varied pressure and rotational transform profiles on the global, ideal magnetohydrodynamic (MHD) stability and the energetic particle transport. The CAS3D and TERPSICHORE code packages were used in the MHD studies while the ORBITMN/ORBIT3D code package was used for the transport simulations of the three field period QAS. To assess robust performance in a medium-size experiment, the VMEC code was used to obtain magnetic flux surfaces for 30 equilibria near the design point, while keeping the boundary shape and the average beta fixed at 3.8%. The plasma equilibria obtained were designated P0X/I0Y as follows: P00/I00 was the baseline configuration. P01, P02 and P03 were defined so that P01 was similar to P00, P02 was more peaked than P01, while P03 was broader than P01. P04 was a very broad, parabolic pressure profile and P05 was the pressure profile used in helias reactor studies based on the W7-X design. The iota profiles were chosen as follows: I01 was linear, maintaining i(0) and i(a) the same as in I00. I02 and I03 were based on I01 and also kept i(0) and i(a) as …
Date: July 7, 2000
Creator: Redi, M. H.; Cooper, W. A.; Diallo, A.; Fu, G. Y.; Nuehrenberg, C.; Reiman, A. H. et al.
System: The UNT Digital Library
The ASCI Network for SC '99: A Step on the Path to a 100 Gigabit Per Second Supercomputing Network (open access)

The ASCI Network for SC '99: A Step on the Path to a 100 Gigabit Per Second Supercomputing Network

This document highlights the Discom{sup 2}'s Distance computing and communication team activities at the 1999 Supercomputing conference in Portland, Oregon. This conference is sponsored by the IEEE and ACM. Sandia, Lawrence Livermore and Los Alamos National laboratories have participated in this conference for eleven years. For the last four years the three laboratories have come together at the conference under the DOE's ASCI, Accelerated Strategic Computing Initiatives rubric. Communication support for the ASCI exhibit is provided by the ASCI DISCOM{sup 2} project. The DISCOM{sup 2} communication team uses this forum to demonstrate and focus communication and networking developments within the community. At SC 99, DISCOM built a prototype of the next generation ASCI network demonstrated remote clustering techniques, demonstrated the capabilities of the emerging Terabit Routers products, demonstrated the latest technologies for delivering visualization data to the scientific users, and demonstrated the latest in encryption methods including IP VPN technologies and ATM encryption research. The authors also coordinated the other production networking activities within the booth and between their demonstration partners on the exhibit floor. This paper documents those accomplishments, discusses the details of their implementation, and describes how these demonstrations support Sandia's overall strategies in ASCI networking.
Date: July 24, 2000
Creator: Pratt, Thomas J.; Tarman, Thomas D.; Martinez, Luis M.; Miller, Marc M.; Adams, Roger L.; Chen, Helen Y. et al.
System: The UNT Digital Library
Making connections: Case studies of interconnection barriers and their impact on distributed power projects (open access)

Making connections: Case studies of interconnection barriers and their impact on distributed power projects

Distributed power is modular electric generation or storage located close to the point of use. Based on interviews of distributed generation project proponents, this report reviews the barriers that distributed generators of electricity are encountering when attempting to interconnect to the electrical grid. Descriptions of 26 of 65 case studies are included in the report. The survey found and the report describes a wide range of technical, business-practice, and regulatory barriers to interconnection. An action plan for reducing the impact of these barriers is also included.
Date: July 25, 2000
Creator: Alderfer, B.; Eldridge, M. & Starrs, T.
System: The UNT Digital Library
Report of official foreign travel to France, June 7--20, 2000 (open access)

Report of official foreign travel to France, June 7--20, 2000

The Department of Energy (DOE) has moved rapidly toward electronic production, management, and dissemination of scientific and technical information. The World-Wide Web (WWW) has become a primary means of information dissemination. Electronic commerce (EC) is becoming the preferred means of procurement. DOE, like other government agencies, depends on and encourages the use of international standards in data communications. Like most government agencies, DOE has expressed a preference for openly developed standards over proprietary designs promoted as ``standards'' by vendors. In particular, there is a preference for standards developed by organizations such as the International Organization for Standardization (ISO) and the American National Standards Institute (ANSI) that use open, public processes to develop their standards. Among the most widely adopted international standards is the Standard Generalized Markup Language (SGML, ISO 8879:1986, FIPS 152), to which DOE long ago made a commitment. Besides the official commitment, which has resulted in several specialized projects, DOE makes heavy use of coding derived from SGML: Most documents on the WWW are coded in HTML (Hypertext Markup Language), which is an application of SGML. The World-Wide Web Consortium (W3C), with the backing of major software houses like Adobe, IBM, Microsoft, Netscape, Oracle, and Sun, is promoting …
Date: July 11, 2000
Creator: Mason, J. D.
System: The UNT Digital Library
Optimization of Cesium Removal from Hanford Envelope A Simulant with SuperLig 639 Ion Exchange Resin (open access)

Optimization of Cesium Removal from Hanford Envelope A Simulant with SuperLig 639 Ion Exchange Resin

Hanford RadioactiveWaste materials have been categorized into four envelopes labeled A through D as specified in the Tank Waste Remediation Contract between BNFL and DOE. 1 Envelopes A, B and C contain only solubilized species and are specified as Low-Activity Waste (LAW). Each envelope is defined based on compositional maximums of chemical and radioactive constituents. Envelopes A and B contain low concentrations of organic species and the primary form of technetium is pertechnetate (TcO4-). Envelope C contains higher levels of organic species and technetium which is primarily in the nonpertechnetate form (presumably complexed TcO2). Envelope D is sludge which has been separated from the supernate and is referred to as High Activity Waste. The current plant design utilizes SuperLig ion exchange resins to remove cesium and technetium (the primary radioactive constituents) from the Hanford LAW. The process is designed to produce a decontaminated waste stream and a concentrated eluate waste stream for vitrification into low and high activity glasses, respectively.
Date: July 27, 2000
Creator: King, W.D.
System: The UNT Digital Library
Measurement of Tritium in Gas Phase Soil Moisture and Helium-3 in Soil Gas at the Hanford Townsite and 100 K Area (open access)

Measurement of Tritium in Gas Phase Soil Moisture and Helium-3 in Soil Gas at the Hanford Townsite and 100 K Area

In 1999, soil gas samples for helium-3 measurements were collected at two locations on the Hanford Site. Eight soil gas sampling points ranging in depth from 1.5 to 9.8 m (4.9 to 32 ft) below ground surface (bgs) in two clusters were installed adjacent to well 699-41-1, south of the Hanford Townsite. Fifteen soil gas sampling points, ranging in depth from 2.1 to 3.2 m (7 to 10.4 ft) bgs, were installed to the north and east of the 100 KE Reactor. Gas phase soil moisture samples were collected using silica gel traps from all eight sampling locations adjacent to well 699-41-1 and eight locations at the 100 K Area. No detectable tritium (<240 pCi/L) was found in the soil moisture samples from either the Hanford Townsite or 100 K Area sampling points. This suggests that tritiated moisture from groundwater is not migrating upward to the sampling points and there are no large vadose zone sources of tritium at either location. Helium-3 analyses of the soil gas samples showed significant enrichments relative to ambient air helium-3 concentrations with a depth dependence consistent with a groundwater source from decay of tritium. Helium-3/helium-4 ratios (normalized to the abundances in ambient air) at …
Date: July 5, 2000
Creator: Olsen, KB; Patton, GW; Poreda, R; Dresel, PE & Evans, JC
System: The UNT Digital Library
Evaluation of SuperLig 639 Ion Exchange Resin for the Removal of Rhenium from Hanford Envelope A Simulant (open access)

Evaluation of SuperLig 639 Ion Exchange Resin for the Removal of Rhenium from Hanford Envelope A Simulant

Hanford Radioactive Waste materials have been categorized into four envelopes labeled A through D as specified in the Tank Waste Remediation Contract between BNFL and DOE. 1 Envelopes A, B and C contain only solubilized species and are specified as Low-Activity Waste (LAW). Each envelope is defined based on compositional maximums of chemical and radioactive constituents. Envelopes A and B contain low concentrations of organic species and the primary form of technetium is pertechnetate (TcO4-). Envelope C contains higher levels of organic species and technetium which is primarily in the nonpertechnetate form (presumably complexed TcO2). Envelope D is sludge which has been separated from the supernate and is referred to as High Activity Waste. The current plant design utilizes SuperLig ion exchange resins to remove cesium and technetium (the primary radioactive constituents) from the Hanford LAW. The process is designed to produce a decontaminated waste stream and a concentrated eluate waste stream for vitrification into low and high activity glasses, respectively.
Date: July 27, 2000
Creator: King, W.D.
System: The UNT Digital Library
T Plant overpack tiedown analysis (open access)

T Plant overpack tiedown analysis

This tiedown evaluation meets the requirement imposed by HNF-6550, Safety Evaluation for Packaging (Onsite) T Plant Canyon Items, (O'Brien 2000). O'Brien (2000) requires that any items prepared for shipment from T Plant to the burial grounds that are not bounded by the analysis in O'Brien (2000) must have a separate, approved, engineered tiedown analysis. The width of the overpack box is 9 ft. 7 in. This width is wider than the maximum width authorized in O'Brien (2000), which is 8 ft.
Date: July 31, 2000
Creator: Riley, D.L.
System: The UNT Digital Library
Phase I and II Results from Sr and TRU Precipitation Tests (open access)

Phase I and II Results from Sr and TRU Precipitation Tests

The BNFL removal processes for strontium and transuranic components from the AN-102 and AN-107 supernate originally proposed are co-precipitation methods. In initial testing, the precipitates formed during the strontium and ferric nitrate additions were not filterable.
Date: July 27, 2000
Creator: Wilmarth, W.
System: The UNT Digital Library
Signatures of mode conversion and kinetic Alfven waves at the magnetopause (open access)

Signatures of mode conversion and kinetic Alfven waves at the magnetopause

It has been suggested that resonant mode conversion of compressional MHD waves into kinetic Alfven waves at the magnetopause can explain the abrupt transition in wave polarization from compressional to transverse commonly observed during magnetopause crossings. The authors analyze magnetic field data for magnetopause crossings as a function of magnetic shear angle (defined as the angle between the magnetic fields in the magnetosheath and magnetosphere) and compare with the theory of resonant mode conversion. The data suggest that amplification in the transverse magnetic field component at the magnetopause is not significant up to a threshold magnetic shear angle. Above the threshold angle significant amplification results, but with weak dependence on magnetic shear angle. Waves with higher frequency are less amplified and have a higher threshold angle. These observations are qualitatively consistent with theoretical results obtained from the kinetic-fluid wave equations.
Date: July 21, 2000
Creator: Johnson, Jay R. & Cheng, C. Z.
System: The UNT Digital Library
Deliverable 2.4.4 -- Evaluation and single-well models for the demonstration wells, Class 1 (open access)

Deliverable 2.4.4 -- Evaluation and single-well models for the demonstration wells, Class 1

Two single-well models were developed for Michelle Ute and Malnar Pike wells. The perforated intervals span thousands of feet in both the wells. Geological properties were calculated for all the perforated beds. The information was used to develop models for these two wells. These were comprehensive models since they took into account all the perforated beds.
Date: July 12, 2000
Creator: Deo, Milind & D., Morgan Craig
System: The UNT Digital Library
Electron Bernstein wave electron temperature profile diagnostic (open access)

Electron Bernstein wave electron temperature profile diagnostic

Electron cyclotron emission (ECE) has been employed as a standard electron temperature profile diagnostic on many tokamaks and stellarators, but most magnetically confined plasma devices cannot take advantage of standard ECE diagnostics to measure temperature. They are either overdense, operating at high density relative to the magnetic field (e.g. where the plasma frequency is much greater than the electron cyclotron frequency, as in a spherical torus) or they have insufficient density and temperature to reach the blackbody condition. Electron Bernstein waves (EBWs) are electrostatic waves that can propagate in overdense plasmas and have a high optical thickness at the electron cyclotron resonance layers, as a result of their large perpendicular wavenumber. This paper reports on measurements of EBW emission on the CDX-U spherical torus, where B{sub o} {approximately} 2 kG, <n{sub e}> {approximately}10{sup 13} cm{sup {minus}3} and T{sub e} {approx} to 10 -- 200 eV. Results are presented for electromagnetic measurements of EBW emission, mode-converted near the plasma edge. The EBW emission was absolutely calibrated and compared to the electron temperature profile measured by a multi-point Thomson scattering diagnostic. Depending on the plasma conditions, the mode converted EBW radiation temperature was found to be less than or equal to T{sub …
Date: July 20, 2000
Creator: Taylor, G.; Efthimion, P.; Jones, B.; Munsat, T.; Spaleta, J.; Hosea, J. et al.
System: The UNT Digital Library
The Effect of Pressure and Organic Constituents on the Cesium Ion Exchange Performance of IONSIV IE-911 (open access)

The Effect of Pressure and Organic Constituents on the Cesium Ion Exchange Performance of IONSIV IE-911

This study examined cesium ({sup 137}Cs) ion exchange of crystalline silicotitanate (CST) in simulated waste solution. In particular, the study focused on the effect of CST pretreatment on the kinetics and extent of cesium adsorption. The test used IONSIV{reg_sign}IE-911 (UOP LLC, Molecular Sieves Division, Des Plaines, IL), the engineered form of CST. Pretreatment steps examined include: soaking CST in 2M NaOH solution for three days, exposing CST to 50% relative humidity for one week, flowing organic-containing (saturated) salt solution through a CST packed bed (at 5 cm/min. superficial velocity), or drying CST in air at 100 C for three days. Some tests occurred under 50 and 25 psig of argon. The following conclusions summarize the results. Pretreatment of IE-911 in organic-containing (e.g., tri-n-butyl phosphate, dibutylphosphate, butanol, paraffin and Dow Corning H-10 defoamer) simulated waste or simulated waste yielded a 83% slower rate of cesium adsorption and 56% lower cesium capacity after one week. Pretreatment of IE-911 in 2M caustic solution for 48 hours yielded a slower approach to equilibrium cesium distribution in batch contact tests--7.7 mL/(g*h) during the first 48 hours and 2.4 ml/(g*h) thereafter. Carboxylates and adsorbed carbonates inside the pores likely affect the cesium transport by either increasing …
Date: July 18, 2000
Creator: Fondeur, F. F.
System: The UNT Digital Library
Results of Waste Transfer and Back-Dilution in Tanks 241-SY-101 and 241-SY-102 (open access)

Results of Waste Transfer and Back-Dilution in Tanks 241-SY-101 and 241-SY-102

This report chronicles the process of remediation of the flammable gas hazard in Tank 241-SY-101 (SY-101) by waste transfer and back-dilution from December 18, 1999 through April 2, 2000. A brief history is given of the development of the flammable gas retention and release hazard in this tank, and the transfer and dilution systems are outlined. A detailed narrative of each of the three transfer and dilution campaigns is given to provide structure for the balance of the report. Details of the behavior of specific data are then described, including the effect of transfer and dilution on the waste levels in Tanks SY-101 and SY-102, data from strain gauges on equipment suspended from the tank dome, changes in waste configuration as inferred from neutron and gamma logs, headspace gas concentrations, waste temperatures, and the mixerpump operating performance. Operating data and performance of the transfer pump in SY-101 are also discussed.
Date: July 26, 2000
Creator: Mahoney, L. A.; Antoniak, Z. I.; Barton, W. B.; Conner, J. M.; Kirch, N. W.; Stewart, C. W. et al.
System: The UNT Digital Library
Fusion ignition research experiment (open access)

Fusion ignition research experiment

Understanding the properties of high gain (alpha-dominated) fusion plasmas in an advanced toroidal configuration is the largest remaining open issue that must be addressed to provide the scientific foundation for an attractive magnetic fusion reactor. The critical parts of this science can be obtained in a compact high field tokamak which is also likely to provide the fastest and least expensive path to understanding alpha-dominated plasmas in advanced toroidal systems.
Date: July 18, 2000
Creator: Meade, Dale
System: The UNT Digital Library
Correlation of producing Fruitland Formation coals within the western outcrop and coalbed methane leakage on the Southern Ute Reservation (open access)

Correlation of producing Fruitland Formation coals within the western outcrop and coalbed methane leakage on the Southern Ute Reservation

The Colorado Geological Survey and Southern Ute Indian Tribe proposed to determine the cause of several gas seeps which are occurring on the western outcrop of the coalbed methane producing Fruitland Formation on the Southern Ute Indian Reservation. Correlation between outcrop coals and subsurface coals was necessary to determine seep source in the northern part of the study area. Subsurface studies include structure and net coal isopach maps, stratigraphy was cross-sections, production maps, and a production database. Detailed coal stratigraphy was correlated through production wells near the outcrop region. These maps and cross-sections were correlated to new surface outcrop maps generated by the Colorado, Geological Survey and the Southern Ute Division of Energy Resources. Methane gas seepage has been noted historically within the study area. The total investigation may help determine if gas seepage is natural, a result of coalbed methane development, or some combination of the above.
Date: July 7, 2000
Creator: Carroll, Christopher J. Mathews, Stephanie, Wickman, Barbara
System: The UNT Digital Library
SuperLig Ion Exchange Resin Swelling and Buoyancy Study (open access)

SuperLig Ion Exchange Resin Swelling and Buoyancy Study

The objective of this study was to achieve a fundamental understanding of SuperLig resin swelling and shrinking characteristics, which lead to channeling and early breakthrough during loading cycles. The density of salt solution that causes resin floating was also determined to establish a limit for operation. Specific tests performed include (a) pH dependence, (b) ionic strength dependence and (c) buoyancy effect vs. simulant composition.
Date: July 27, 2000
Creator: Hassan, N. M.
System: The UNT Digital Library
Small-Scale Ion Exchange Removal of Cesium and Technetium from Hanford Tank 241-AN-103 (open access)

Small-Scale Ion Exchange Removal of Cesium and Technetium from Hanford Tank 241-AN-103

The pretreatment process for BNFL, Inc.'s Hanford River Protection Project is to provide decontaminated low activity waste and concentrated eluate streams for vitrification into low activity and high level waste glass, respectively. The pretreatment includes sludge washing, filtration, precipitation, and ion exchange processes to remove entrained solids, cesium, transuranics, technetium, and strontium. The ion exchange removal of cesium (Cs) and technetium (Tc) ions is accomplished by using SuperLig 644, and 639 resins from IBC Advanced Technologies, American Fork, Utah. The resins were shown to selectively remove cesium and technetium (as pertechnetate), from alkaline salt solutions. The efficiency of ion exchange column loading and elution is a complex function involving feed compositions, equilibrium and kinetic behavior of ion exchange resins, diffusion, and the ionic strength and pH of the aqueous solution. A previous experimental program completed at the Savannah River Technology Center demonstrated the conceptualized flow sheet parameters with a similar Hanford tank sample (241-AW-101). Those experiments included determination of Cs and Tc batch distribution coefficients by SuperLig 644 and 639 resins and demonstration of small-scale column breakthrough and elution. The experimental findings were used in support of preliminary design bases and pretreatment flow sheet development by BNFL, Inc.
Date: July 27, 2000
Creator: Hassan, N. M.
System: The UNT Digital Library
Theory, simulation, and experimental studies of zonal flows (open access)

Theory, simulation, and experimental studies of zonal flows

The authors report on current theoretical understanding of the characteristics of self-generated zonal flows as observed in nonlinear gyrokinetic simulations of toroidal ITG turbulence [Science 281, 1835 (1998)], and discuss various possibilities for experimental measurements of signature of zonal flows.
Date: July 13, 2000
Creator: Hahm, T. S.; K.H.Burrell; Z.Lin; Nazikian, R. & Synakowski, E.J.
System: The UNT Digital Library