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Fiscal Year 2004
15
Fiscal Year 2005
12
OIT Tip Sheets
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Habitat Evaluation Procedures Report
10
Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products Quarterly Report
6
Small Wind Electric Systems Consumers' Guides
6
Diffusion Coatings for Corrosion-Resistant Components in Coal Gasification Systems Quarterly Report
5
Proceedings of RIKEN BNL Research Center Workshop
5
Refractory for Black Liquor Gasifiers Quarterly Report
5
Analysis of Devonian Black Shales in Kentucky for Potential Carbon Dioxide Sequestration and Enhanced Natural Gas Production Quarterly Report
4
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Biodiesel--Clean, Green Diesel Fuel: Great Fleet Fuel Gaining Popularity Rapidly
A fact sheet that answers common questions about Biodiesel, including use, safety, and environmental questions.
Date:
July 29, 2005
Creator:
Tyson, K.S.
Object Type:
Book
System:
The UNT Digital Library
Angularly resolved measurements of ion energy of vacuum arc plasmas
None
Date:
April 8, 2005
Creator:
Anders, Andre & Yushkov, George Yu.
Object Type:
Article
System:
The UNT Digital Library
The Effect of Ionizing Radiation U6+ Phases
None
Date:
October 19, 2005
Creator:
Utsunomiya, S. & Ewing, R. C.
Object Type:
Article
System:
The UNT Digital Library
Density distribution for a polymer adsorbed at an oil-water interface
None
Date:
August 22, 2005
Creator:
Cai, Jun & Prausnitz, John M.
Object Type:
Article
System:
The UNT Digital Library
AFCI UFP, Final Technical Report DE-FC07-00AL67053
The project ''Creating an Educational Consortium to Support the Recruitment and Retention of Expertise for the Nuclear Weapons Complex'' was also known as the Advanced Fuel Cycle Initiative (AFCI) University Fellowship Program. Since its inception, the Advanced Fuel Cycle Initiative program and its predecessor, the Advanced Accelerator Applications (AAA) program, have engaged university researchers and students in the sciences necessary to answer technical questions related to reducing high-level waste volumes, optimizing the economics and performance of Yucca Mountain, reducing the technical need for a second repository, reducing the long-term inventories of plutonium in spent fuel, and enabling the proliferation-resistant recovery of the energy contained in spent fuel. The Advanced Fuel Cycle University Fellowship Program is intended to support top students across the nation in a variety of disciplines that will be required to support transmutation research and technology development in the coming decades.
Date:
February 21, 2005
Creator:
Dixon, Cathy
Object Type:
Report
System:
The UNT Digital Library
Development of an Experimental Data Base and Theories for Prediction of Thermodynamic Properties of Aqueous Electrolytes and Nonelectrolytes of Geochemical Significance at Supercritical Temperatures and Pressures.
The objective of this research was to combine new experimental measurements on heat capacities, volumes, and association constants of key compounds with theoretical equations of state and with first principles quantum mechanical calculations to generate predictions of thermodynamic data. The resulting thermodynamic data allow quantitative models of geochemical processes at high temperatures and pressures. Research funded by a DOE grant to Prof. Robert Wood at the University of Delaware involved the development of new theoretical equations of state for aqueous solutions of electrolytes and non-electrolytes, methods to estimate thermodynamic data not available from experiments, collection of data on model compounds through experiments and predictions of properties using ab initio quantum mechanics. During the last three and a half years, with support from our DOE grant, 16 papers have been accepted or published, and 3 more are in preparation. Results of this research have been reported in numerous invited and contributed presentations at national and international meetings. For this report, we will briefly comment on the highlights of the last 3 and a half years and give a complete list of papers published, accepted, or submitted during these years.
Date:
October 11, 2005
Creator:
Wood, Robert H.
Object Type:
Report
System:
The UNT Digital Library
REFINERY INTEGRATION OF BY-PRODUCTS FROM COAL-DERIVED JET FUELS
This report summarizes the accomplishments toward project goals during the first six months of the second year of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts, acquisition and installation of a research gasoline engine, and modification of diesel engines for use in evaluating diesel produced in the project. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Coal samples have procured and are being assessed for cleaning prior to use in coking studies.
Date:
May 18, 2005
Creator:
Rudnick, Leslie R.; Boehman, Andre; Song, Chunshan; Miller, Bruce & Mitchell, Gareth
Object Type:
Report
System:
The UNT Digital Library
Duct Tape and Sealant Performance
None
Date:
March 1, 2005
Creator:
Walker, Iain S. & Sherman, Max H.
Object Type:
Article
System:
The UNT Digital Library
RADIONUCLIDE DISPERSION RATES BY AEOLIAN, FLUVIAL, AND POROUS MEDIA TRANSPORT
Radionuclide transport was measured from high grade uranium ore boulders near the Nopal I Site, Chihuahua, Mexico. High grade uranium ore boulders were left behind after removal of a uranium ore stockpile at the Prior High Grade Stockpile (PHGS). During the 25 years when the boulder was present, radionuclides were released and transported by sheetflow during precipitation events, wind blown resuspension, and infiltration into the unsaturated zone. In this study, one of the boulders was removed, followed by grid sampling of the surrounding area. Measured gamma radiation levels in three dimensions were used to derive separate dispersion rates by the three transport mechanisms.
Date:
July 11, 2005
Creator:
Walton, J.; Goodell, P.; Brashears, C.; French, D. & Kelts, A.
Object Type:
Report
System:
The UNT Digital Library
SYNTHESIS AND CHARACTERIZATION OF CO- AND H{sub 2}S-TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL
The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to reduce the Pt-loading and improve the PEMFC performance, we propose to synthesize a number of Pt-based binary, ternary, and quaternary electrocatalysts using Ru, Mo, Ir, Ni, and Co as a substitute for Pt. By fine-tuning the metal loadings and compositions of candidate electrocatalysts, we plan to minimize the cost and optimize the catalyst activity and performance in PEMFC. The feasibility of the novel electrocatalysts will be demonstrated in the proposed effort with gas phase CO and H{sub 2}S concentrations typical of those found in reformed fuel gas with coal/natural gas/methanol feedstocks. During this reporting period several tri-metallic electrocatalysts were synthesized using both ultra-sonication and conventional method. These catalysts (Pt/Ru/Mo, Pt/Ru/Ir, Pt/Ru/W, Ptr/Ru/Co, and Pt/Ru/Se on carbon) were …
Date:
April 5, 2005
Creator:
Ilias, Shamsuddin
Object Type:
Report
System:
The UNT Digital Library
First Demonstration of Surface Passivation in Dye-Sensitized TiO2 Solar Cells by an Additive in the Electrolyte
The composition of the electrolyte is known to greatly influence the performance of dye-sensitized solar cells. It has been speculated that some components of the electrolyte passivate the TiO2 surface against recombination; however, this has never been confirmed experimentally. We hereby present the first case of passivation of the TiO2 surface against recombination by an additive in the electrolyte. Even though the additive also causes a downward movement of the TiO2 bands, suppression of recombination prevails and an overall improvement in open-circuit photovoltage is observed. This work was conducted in collaboration with the DOE Office of Science program.
Date:
January 1, 2005
Creator:
Kopidakis, N.; Neale, N. R.; van de Lagemaat, J. & Frank, A. J.
Object Type:
Article
System:
The UNT Digital Library
Fermi level stabilization energy in group III-nitrides
Energetic particle irradiation is used to systematically introduce point defects into In{sub 1-x}Ga{sub x}N alloys over the entire composition range. Three types of energetic particles (electrons, protons, and {sup 4}He{sup +}) are used to produce a displacement damage dose spanning five decades. In InN and In-rich InGaN the free electron concentration increases with increasing irradiation dose but saturates at a sufficiently high dose. The saturation is due to Fermi level pinning at the Fermi Stabilization Energy (E{sub FS}), which is located at 4.9 eV below the vacuum level. Electrochemical capacitance-voltage (ECV) measurements show that the pinning of the surface Fermi energy at E{sub FS} is also responsible for the surface electron accumulation in as-grown InN and In-rich InGaN alloys. The results are in agreement with the amphoteric defect model that predicts that the same type of native defects are responsible for the Fermi level pinning in both cases.
Date:
January 7, 2005
Creator:
Li, S. X.; Yu, K. M.; Wu, J.; Jones, R. E.; Walukiewicz, W.; AgerIII, J. W. et al.
Object Type:
Article
System:
The UNT Digital Library
A Widely Tunable Infrared Laser Spectrometer for Measurements of Isotopic Ratios of Carbon Cycle Gases
The atmospheric abundances of carbon dioxide and methane have increased dramatically during the industrial era. Measurements of the isotopic composition of these gases can provide a powerful tool for quantifying their sources and sinks. This report describes the development of a portable instrument for isotopic analysis CO{sub 2} and CH{sub 4} using tunable infrared laser absorption spectroscopy. This instrument combines novel optical design and signal processing methods with a widely tunable mid-infrared laser source based on difference frequency generation (DFG) which will can access spectral regions for all the isotopes of CO{sub 2} and CH{sub 4} with a single instrument. The instrument design compensates for the large difference in concentration between major and minor isotopes by measuring them with path lengths which differ by a factor of 100 within the same multipass cell. During Phase I we demonstrated the basic optical design and signal processing by determining {sup 13}CO{sub 2} isotopic ratios with precisions as small as 0.2{per_thousand} using a conventional lead salt diode laser. During Phase II, the DFG laser source was coupled with the optical instrument and was demonstrated to detect {sup 13}CH{sub 4}/{sup 12}CH{sub 4} ratios with a precision of 0.5{per_thousand} and an averaging time of 20 …
Date:
January 31, 2005
Creator:
Shorter, Joanne H.; McManus, J. Barry; Nelson, David D.; Kolb, Charles E.; Zahniser, Mark S.; Bambha, Ray et al.
Object Type:
Report
System:
The UNT Digital Library
Synthesis, Structure, and Reactivity ofbis(1,2,4-tri-t-butylcyclopentadienyl) Complexes of Cerium
The sterically demanding 1,2,4-tri-t-butylcyclopentadienylligand (1,2,4-(Me3C)3C5H2, hereafter Cp') has been used to preparemonomeric cerium metallocenes, Cp 2CeX (X = Cl, I, OSO2CF3), which areused to synthesize the benzyl, Cp'2CeCH2C6H5. The benzyl is a usefulstarting material for preparing other complexes in the Cp'2CeZ system (Z= BF4, F, NH2, C6H5, H). X-ray crystal structures of Cp'2CeOSO2CF3,Cp'2CeF, Cp'2CeCH2C6H5, and Cp'2CeH are presented. The benzyl slowlydecomposes in solution to toluene and a metallacycle,[Cp'][(Me3C)2C5H2(CMe2CH2)]Ce. The ring CMe3 groups of both themetallacycle and the hydride, Cp'2CeH, can be fully deuterated byprolonged exposure to C6D6, providing a useful labeling tool inmechanistic studies.The hydride activates C-F and/or C-H bonds influorobenzenes, C6HxF6-x , x = 0-5. The reactions are selective, with theselectivity depending on the presence of two fluorines ortho to thereaction site more than on the type of bond activated. Complexes of thetype Cp'2CeC6HxF5-x , x = 0-4, are formed as intermediates, which slowlydecompose in solution to Cp'2CeF and fluorobenzynes, C6HxF4-x, x = 0-4,which are trapped. The rate at which Cp'2CeC6HxF5-x complexes decomposeincreases as the number of fluorines decreases. Complexes with oneortho-fluorine decompose much faster than those with two ortho-fluorines.The metallacycle activates only C-H bonds in fluorobenzenes, permittingthe synthesis of specific Cp'2CeC6HxF5-x complexes. The crystal structureof Cp'2CeC6F5 is presented. …
Date:
May 19, 2005
Creator:
Werkema, Evan L.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
MODELING AND DESIGN FOR A DIRECT CARBON FUEL CELL WITH ENTRAINED FUEL AND OXIDIZER
The novel molten carbonate fuel cell design described in this report uses porous bed electrodes. Molten carbonate, with carbon fuel particles and oxidizer entrained, is circulated through the electrodes. Carbon may be reacted directly, without gasification, in a molten carbonate fuel cell. The cathode reaction is 2CO{sub 2} + O{sub 2} 4e{sup -} {yields} 2CO{sub 3}{sup =}, while the anode reaction can be either C + 2CO{sub 3}{sup =} {yields} 3CO{sub 2} + 4e{sup -} or 2C + CO{sub 3}{sup =} {yields} 3CO + 2e{sup -}. The direct carbon fuel cell has an advantage over fuel cells using coal-derived synthesis gas in that it provides better overall efficiency and reduces equipment requirements. Also, the liquid electrolyte provides a means for transporting the solid carbon. The porous bed cell makes use of this carbon transport ability of the molten salt electrolyte. A one-dimensional model has been developed for predicting the performance of this cell. For the cathode, dependent variables are superficial O{sub 2} and CO{sub 2} fluxes in the gas phase, superficial O{sub 2} and CO{sub 2} fluxes in the liquid phase, superficial current density through the electrolyte, and electrolyte potential. The variables are related by correlations, from the literature, for …
Date:
April 1, 2005
Creator:
Kornhauser, Alan A. & Agarwal, Ritesh
Object Type:
Report
System:
The UNT Digital Library
A New Concept for the Fabrication of Hydrogen Selective Silica Membranes
It is attempted to synthesize hydrogen selective silica-based membranes through a novel thin film deposition concept. This report describes the progress made during the 1st Year of this award. All project Tasks, for Year 1, were completed and the first thin films were prepared and characterized. The goal of this work is to use crystalline layered silicates to form hydrogen selective membranes for use in high temperature hydrogen/carbon dioxide separations. It was proposed to: (A) Synthesize layered silicate materials; (B) Prepare dispersions of as synthesized or delaminated layered silicates; (C) Prepare membranes by coating the layered silicates on macro-mesoporous supports; and (D) Test the membranes for H{sub 2}/CO{sub 2} selectivity at high temperature and pressures and for structural and functional stability at high temperature in the presence of water vapor. All Year 1 project Tasks are completed. Layered silicate particles were synthesized hydrothermally. Crystal shape and size was optimized for the formation of thin films. Calcination procedures that avoid particle agglomeration were developed and suspensions of the calcined silicate particles were prepared. The silicate particles and suspensions were characterized by X-Ray Diffraction, Electron Microscopy and Dynamic Light Scattering. The characterization data indicate that plate like morphology, large aspect ratio and …
Date:
October 1, 2005
Creator:
Tsapatsis, Michael
Object Type:
Report
System:
The UNT Digital Library
Cathode/Interconnect Interactions
The objectives of this project were to examine chromium poisoning in full cell tests, evaluate chromium release rates for oxides, and examine the effects of chromium in the cathode.
Date:
January 27, 2005
Creator:
Krumpelt, M.; Cruse, T.A. & Hash, M.
Object Type:
Presentation
System:
The UNT Digital Library
Emissions Inventory Report Summary: Reporting Requirements for the New Mexico Administrative Code, Title 20, Chapter 2, Part 73 (20.2.73 NMAC) for Calendar Year 2003
Los Alamos National Laboratory is subject to annual emissions-reporting requirements for regulated air pollutants under Title 20 of the New Mexico Administrative Code, Chapter 2, Part 73 (20.2.73 NMAC), Notice of Intent and Emissions Inventory Requirements. The applicability of the requirements is based on the Laboratory's potential to emit 100 tons per year of suspended particulate matter, nitrogen oxides, carbon monoxide, sulfur oxides, or volatile organic compounds. For calendar year 2003, the Technical Area 3 steam plant and the air curtain destructors were the primary sources of criteria air pollutants from the Laboratory, while the air curtain destructors and chemical use associated with research and development activities were the primary sources of volatile organic compounds and hazardous air pollutants. Emissions of beryllium and aluminum were reported for activities permitted under 20.2.72 NMAC. Hazardous air pollutant emissions were reported from chemical use as well as from all combustion sources. In addition, estimates of particulate matter with diameter less than 2.5 micrometers and ammonia were provided as requested by the New Mexico Environment Department, Air Quality Bureau.
Date:
January 1, 2005
Creator:
Stockton, M.
Object Type:
Report
System:
The UNT Digital Library
Gene expression profiles of Nitrosomonas europaea, an obligate chemolitotroph
Nitrosomonas europaea is an aerobic lithoautotrophic bacterium that uses ammonia (NH3) as its energy source. As a nitrifier, it is an important participant in the nitrogen cycle, which can also influence the carbon cycle. The focus of this work was to explore the genetic structure and mechanisms underlying the lithoautotrophic growth style of N. europaea. Whole genome gene expression: The gene expression profile of cells in exponential growth and during starvation was analyzed using microarrays. During growth, 98% of the genes increased in expression at least two fold compared to starvation conditions. In growing cells, approximately 30% of the genes were expressed eight fold higher, Approximately 10% were expressed more than 15 fold higher. Approximately 3% (91 genes) were expressed to more than 20 fold of their levels in starved cells. Carbon fixation gene expression: N. europaea fixes carbon via the Calvin-Benson-Bassham (CBB) cycle via a type I ribulose bisphosphate carboxylase/oxygenase (RubisCO). This study showed that transcription of cbb genes was up-regulated when the carbon source was limited, while amo, hao and other energy harvesting related genes were down-regulated. Iron related gene expression: Because N. europaea has a relatively high content of hemes, sufficient Fe must be available in the …
Date:
May 25, 2005
Creator:
Arp, Daniel J.
Object Type:
Report
System:
The UNT Digital Library
A Reference-Dependent Regret Model for Deterministic Trade-off Studies
Today's typical multi-criteria decision analysis is based on classical expected utility theory that assumes a mythical ''Rational Individual'' immune to psychological influences such as anticipated regret. It is therefore in conflict with rational individuals who trade-off some benefits and forgo the alternative with the highest total classical utility for a more balanced alternative in order to reduce their levels of anticipated regret. This paper focuses on decision making under certainty. It presents a reference-dependent regret model (RDRM) in which the level of regret that an individual experiences depends on the absolute values rather than the differences of the utilities of the chosen and forgone alternatives. The RDRM best choice may differ from the conventional linear additive utility model, the analytic hierarchy process, and the regret theory of Bell and Loomes and Sugden. Examples are presented that indicate that RDRM is the better predictive descriptor for decision making under certainty. RDRM satisfies transitivity of the alternatives under pairwise comparisons and models rank reversal consistent with observed reasonable choices under dynamic or distinct situations. Like regret theory, the RDRM utilities of all the alternatives under consideration are interrelated. For complex trade-off studies regret is incorporated as an element of a cost-utility-regret analysis …
Date:
February 25, 2005
Creator:
Kujawski, Edouard
Object Type:
Article
System:
The UNT Digital Library
NANOSTRUCTURED CERAMICS AND COMPOSITES FOR REFRACTORY APPLICATIONS IN COAL GASIFICATION
A class of ceramics, capable of exhibiting low coefficients of thermal expansion and catalytic properties was investigated. Investigations were directed towards nanoengineering of NZP ceramics and NZP-based composites by chemical means by controlling their compositions and processing variables. NaZr{sub 2}(PO{sub 4}){sub 3} (NZP) was synthesized by combining water-soluble precursors leading to the precipitation of a gel that was dried, calcined, pressed into pellets, then fired at 850 C. Without chemical additives, the resulting ceramic comprised pores ranging in size from approximately 25 to 50 nm and a surface area of about 30m{sup 2}/g. Hydroxyapatite, which has a needle-like morphology, was mechanically mixed with the calcined gel to template NZP crystallization. What resulted was a coarsening of the pore structure and a decrease in surface area. When copper nitrate was added to the solution during synthesis, the resulting ceramic underwent shrinkage upon firing as well as an increase in strength. HAp and copper additions combined resulted in 40% volume shrinkage and a doubling of the tensile strength to 16MPa. A very different type of porosity was achieved when silica was partly substituted for phosphorous in the NZP structure. Na{sub 3}Zr{sub 2}(Si{sub 2}P)O{sub 12} (NASCION) was synthesized in the same manner as …
Date:
January 31, 2005
Creator:
Brown, Paul
Object Type:
Report
System:
The UNT Digital Library
Energy Loss, Range, and Electron Yield Comparisons of the CRANGEIon-Material Interaction code
We present comparisons of the CRANGE code to other well-known codes, SRIM and ASTAR, and to experimental results for ion-material interactions such as energy loss per unit length, ion range, and ion induced electron yield. These ion-material interaction simulations are relevant to the electron cloud effect in heavy ions accelerators for fusion energy and high energy density physics. Presently, the CRANGE algorithms are most accurate at energies above 1.0 MeV/amu. For calculations of energy loss per unit length of a potassium ion in stainless steel, results of CRANGE and SRIM agree to within ten percent above 1.0 MeV/amu. For calculations of the range of a helium ion in aluminum, results of CRANGE and ASTAR agree to within two percent above 1.0 MeV/amu. Finally, for calculations of ion induced electron yield for hydrogen ions striking gold, results of CRANGE agree to within ten percent with measured electron yields above 1.0 MeV/amu.
Date:
January 18, 2005
Creator:
Stoltz, P. H.; Veitzer, S. A.; Cohen, R. H.; Molvik, A. W. & J.-L., Vay
Object Type:
Article
System:
The UNT Digital Library
Analysis of High Power IGBT Short Circuit Failures
The Next Linear Collider (NLC) accelerator proposal at SLAC requires a highly efficient and reliable, low cost, pulsed-power modulator to drive the klystrons. A solid-state induction modulator has been developed at SLAC to power the klystrons; this modulator uses commercial high voltage and high current Insulated Gate Bipolar Transistor (IGBT) modules. Testing of these IGBT modules under pulsed conditions was very successful; however, the IGBTs failed when tests were performed into a low inductance short circuit. The internal electrical connections of a commercial IGBT module have been analyzed to extract self and mutual partial inductances for the main current paths as well as for the gate structure. The IGBT module, together with the partial inductances, has been modeled using PSpice. Predictions for electrical paths that carry the highest current correlate with the sites of failed die under short circuit tests. A similar analysis has been carried out for a SLAC proposal for an IGBT module layout. This paper discusses the mathematical model of the IGBT module geometry and presents simulation results.
Date:
February 11, 2005
Creator:
Pappas, G.
Object Type:
Report
System:
The UNT Digital Library
In-Situ Survival Mechanisms of U and Tc Reducing Bacteria in Contaminated Sediments Final Report
The proposed effort will identify genes and ultimately physiological mechanisms and pathways that are expressed under in situ conditions and are critical to functioning of aquifer dwelling anaerobic bacteria living in contaminated systems. The main objectives are: (1) Determine which Metal-reducer specific genes are important for activities in normal and contaminated subsurface sediment. To achieve these goals, we have generated a library of chromosomal mutants. These are introduced into contaminated sediments, incubated, allowed to grow, and then reisolated. A negative selection process allows us to determine which mutants have been selected against in sediments and thereby identify genes required for survival in subsurface sediments. (2) Delineate the function of these genes through GeneBank and Clusters of Orthologous Groups (COGs) comparisons and analyze other sediment microorganisms to determine if similar genes are present in these populations. After determining the sequence of the genes identified through the previous objectives, we delineate the role of those specific genes in the physiology of G20, MR-1 and perhaps other microorganisms. (3) Determine the loss in function of a select group of mutants. Cells with mutations in known genes with testable functions are assayed for the loss of that function if specific assays are available. Mutants …
Date:
July 11, 2005
Creator:
Krumholz, Lee R. & Ballard, Jimmy D.
Object Type:
Report
System:
The UNT Digital Library