Global Cooling: Effect of Urban Albedo on Global Temperature (open access)

Global Cooling: Effect of Urban Albedo on Global Temperature

In many urban areas, pavements and roofs constitute over 60% of urban surfaces (roof 20-25%, pavements about 40%). The roof and the pavement albedo can be increased by about 0.25 and 0.10, respectively, resulting in a net albedo increase for urban areas of about 0.1. Many studies have demonstrated building cooling-energy savings in excess of 20% upon raising roof reflectivity from an existing 10-20% to about 60%. We estimate U.S. potential savings in excess of $1 billion (B) per year in net annual energy bills. Increasing albedo of urban surfaces can reduce the summertime urban temperature and improve the urban air quality. Increasing the urban albedo has the added benefit of reflecting more of the incoming global solar radiation and countering the effect of global warming. We estimate that increasing albedo of urban areas by 0.1 results in an increase of 3 x 10{sup -4} in Earth albedo. Using a simple global model, the change in air temperature in lowest 1.8 km of the atmosphere is estimated at 0.01K. Modelers predict a warming of about 3K in the next 60 years (0.05K/year). Change of 0.1 in urban albedo will result in 0.01K global cooling, a delay of {approx}0.2 years in …
Date: May 22, 2007
Creator: Akbari, Hashem; Menon, Surabi & Rosenfeld, Arthur
Object Type: Article
System: The UNT Digital Library
Phase change in uranium: Discrepancy between experiment and theory (open access)

Phase change in uranium: Discrepancy between experiment and theory

Using a diamond-anvil cell (DAC) phase transformation and room temperature Equation of State (EOS) for some actinides and lanthanides were studied to multimegabar (megabar = 100 GPa) pressures. Experimental data are compared with the theoretically predicted crystal structural changes and the pressure-volume relationships. There is a general agreement between theory and experiment for the structural changes in the lighter actinides, however in detail there are some discrepancies still. A generalized trend for the phase transformations in the lanthanides can be seen, which again has broad agreement with theory. We conclude that an accurate and robust theoretical base for predicting the phase transformations in the f-electron metals can be developed by incorporating the DAC data.
Date: July 22, 1996
Creator: Akella, J.
Object Type: Report
System: The UNT Digital Library
Development of a Novel Catalyst for NO Decomposition (open access)

Development of a Novel Catalyst for NO Decomposition

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation …
Date: June 22, 2007
Creator: Akyurtlu, Ates & Akyurtlu, Jale F.
Object Type: Report
System: The UNT Digital Library
Development of a Novel Catalyst for NO Decomposition (open access)

Development of a Novel Catalyst for NO Decomposition

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation …
Date: October 22, 2004
Creator: Akyurtlu, Ates & Akyurtlu, Jale F.
Object Type: Report
System: The UNT Digital Library
[Generation of a synthetic seismic data base]. Final report (open access)

[Generation of a synthetic seismic data base]. Final report

A consortium (Los Alamos, Sandia, OR, Livermore) have been collaborating under the GONII project to generate a synthetic seismic data base. Two deliverables were a common code that would run on the various site machines, and the use of these codes to generate parts of the final data base. The data base consists of a large number of shots applied to two geographic models developed by another part of GONII, the salt model and the overthrust model,s which were supplied as large files containing propagation velocity on a 3-D grid. Los Alamos was supplied with the source code of a seismic propagation code written by the French Petroleum Institute. A decision was made to port a subset of the code to Fortran on a node. Part of this contract was spent verifying/debugging the Fortran on a node code; a port of the code was made to run on the Cray. A total of 846 shots were run on the CM5. It was found that files on the SDA are not safe from corruption and the model velocity file may change.
Date: October 22, 1995
Creator: Aldrich, C. H., III
Object Type: Report
System: The UNT Digital Library
On reactor type comparisons for the next generation of reactors (open access)

On reactor type comparisons for the next generation of reactors

In this paper, we present a broad comparison of studies for a selected set of parameters for different nuclear reactor types including the next generation. This serves as an overview of key parameters which provide a semi-quantitative decision basis for selecting nuclear strategies. Out of a number of advanced reactor designs of the LWR type, gas cooled type, and FBR type, currently on the drawing board, the Advanced Light Water Reactors (ALWR) seem to have some edge over other types of the next generation of reactors for the near-term application. This is based on a number of attributes related to the benefit of the vast operating experience with LWRs coupled with an estimated low risk profile, economics of scale, degree of utilization of passive systems, simplification in the plant design and layout, modular fabrication and manufacturing. 32 refs., 1 fig., 3 tabs.
Date: August 22, 1991
Creator: Alesso, H.P. & Majumdar, K.C.
Object Type: Article
System: The UNT Digital Library
Correlating radiation exposure with embrittlement: Comparative studies of electron- and neutron-irradiated pressure vessel alloys (open access)

Correlating radiation exposure with embrittlement: Comparative studies of electron- and neutron-irradiated pressure vessel alloys

Comparative experiments using high energy (10 MeV) electrons and test reactor neutrons have been undertaken to understand the role that primary damage state has on hardening (embrittlement) induced by irradiation at 300 C. Electrons produce displacement damage primarily by low energy atomic recoils, while fast neutrons produce displacements from considerably higher energy recoils. Comparison of changes resulting from neutron irradiation, in which nascent point defect clusters can form in dense cascades, with electron irradiation, where cascade formation is minimized, can provide insight into the role that the in-cascade point defect clusters have on the mechanisms of embrittlement. Tensile property changes induced by 10 MeV electrons or test reactor neutron irradiations of unalloyed iron and an Fe-O.9 wt.% Cu-1.0 wt.% Mn alloy were examined in the damage range of 9.0 x 10{sup {minus}5} dpa to 1.5 x 10{sup {minus}2} dpa. The results show the ternary alloy experienced substantially greater embrittlement in both the electron and neutron irradiate samples relative to unalloyed iron. Despite their disparate nature of defect production similar embrittlement trends with increasing radiation damage were observed for electrons and neutrons in both the ternary and unalloyed iron.
Date: December 22, 1999
Creator: Alexander, D. E.; Rehn, L. E.; Odette, G. R.; Lucas, G. E.; Klingensmith, D. & Gragg, D.
Object Type: Article
System: The UNT Digital Library
K Reactor moderator distortion study (open access)

K Reactor moderator distortion study

Irradiation-induced moderator distortion has plagued the Hanford reactors from their earliest days until the present. The first-manifestation of graphite distortion was in the form of expansion of the B, D and F stacks. It was found that expansion was very temperature-dependent and could be reversed by raising the graphite operating temperature. The DR, H, C and K Reactors were designed with provisions to minimize, or accommodate expansion. It was not until after the K Reactors had been designed that graphite contraction was recognized as a threat to stack life. Under the present operating conditions, contraction is largely dependent upon neutron flux levels. To date, this study has been largely concerned with the K Reactors, since the vast bulk of the distortion data available is from the Ks. This study not only attempts to explain the mechanisms by which the K Reactors arrived at their present state of distortion but also provides a basis for forecasting future distortion. An understanding of the nature and magnitude of the forces at work within the stacks will enhance the possibility of devising means of conteracting the present trends.
Date: June 22, 1964
Creator: Alexander, W.K. & Russell, A.
Object Type: Report
System: The UNT Digital Library
Hybridization in the Ensatina Ring Species, Strong selection against hybrids at a hybrid zone in the ensatina ring species complex and its evolutionary implications (open access)

Hybridization in the Ensatina Ring Species, Strong selection against hybrids at a hybrid zone in the ensatina ring species complex and its evolutionary implications

The analysis of interactions between lineages at varying levels of genetic divergence can provide insights into the process of speciation through the accumulation of incompatible mutations. Ring species, and especially the Ensatina eschscholtzii system exemplify this approach. The plethodontid salamanders Ensatina eschscholtzii xanthoptica and Ensatina eschscholtzii platensis hybridize in the Central Sierran foothills of California. We compared the genetic structure across two transects (southern and northern Calaveras Co.), one of which was re-sampled over 20 years, and examined diagnostic molecular markers (eight allozyme loci and mitochondrial DNA) and a diagnostic quantitative trait (color pattern). Key results across all studies were: (i) cline centers for all markers were coincident and the zones were narrow, with width estimates of 730m to 2000m; (ii) cline centers at the northern Calaveras transect were coincident between 1981 and 2001, demonstrating repeatability over 5 generations; (iii) there are very few if any putative F1's, but a relatively high number of backcrossed individuals (57-86 percent) in the central portion of transects; (iv) we found substantial linkage disequilibrium in all three studies and strong heterozygote deficit both in northern Calaveras, in 2001, and southern Calaveras. Both linkage disequilibrium and heterozygote deficit show maximum values near the center of …
Date: April 22, 2005
Creator: Alexandrino, Joao; Baird, Stuart J.E.; Lawson, Lucinda; Macey, J. Robert; Moritz, Craig & Wake, David B.
Object Type: Article
System: The UNT Digital Library
Intracavity Frequency Doubling of a Diode-Pumped, External Cavity, Surface Emitting Semiconductor Laser (open access)

Intracavity Frequency Doubling of a Diode-Pumped, External Cavity, Surface Emitting Semiconductor Laser

The authors present a compact, robust, solid-state blue light (490 nm) source capable of greater than 5 mW of output in a TEM{sub 00} mode. This device is an optically pumped, vertical external-cavity surface-emitting laser (VECSEL) with an intracavity frequency doubling crystal.
Date: April 22, 1999
Creator: Alford, W. J.; Allerman, A. A.; Crawford, M. H. & Raymond, T. D.
Object Type: Article
System: The UNT Digital Library
Quality + safety = productivity: The implosion of Plant 7 (open access)

Quality + safety = productivity: The implosion of Plant 7

At the Fernald Environmental Restoration Management Corporation (FERMCO), our product is a clean site. We measure productivity by our progress in taking down buildings and dispositioning hazardous waste. To those ends, Quality and Safety work together to ensure that productivity is gained in the safest way possible. The Plant 7 deconstruction is an example of how this teamwork has increased productivity at the site.
Date: May 22, 1995
Creator: Alhadeff, N. & Abernathy, L.
Object Type: Article
System: The UNT Digital Library
Searching for R-Parity Violation at Run-II of the Tevatron. (open access)

Searching for R-Parity Violation at Run-II of the Tevatron.

The authors present an outlook for possible discovery of supersymmetry with broken R-parity at Run II of the Tevatron. They first present a review of the literature and an update of the experimental bounds. In turn they then discuss the following processes: (1) resonant slepton production followed by R{sub P} decay, (a) via LQD{sup c} and (b) via LLE{sup c}; (2) how to distinguish resonant slepton production from Z{prime} or W{prime} production; (3) resonant slepton production followed by the decay to neutralino LSP, which decays via LQD{sup c}; (4) resonant stop production followed by the decay to a chargino, which cascades to the neutralino LSP; (5) gluino pair production followed by the cascade decay to charm squarks which decay directly via L{sub 1}Q{sub 2}D{sub 1}{sup c}; (6) squark pair production followed by the cascade decay to the neutralino LSP which decays via L{sub 1}Q{sub 2}D{sub 1}{sup c}; (7) MSSM pair production followed by the cascade decay to the LSP which decays (a) via LLE{sup c}, (b) via LQD{sup c}, and (c) via U{sup c}D{sup c}D{sup c}, respectively; and (8) top quark and top squark decays in spontaneous R{sub P}.
Date: June 22, 1999
Creator: Allanach, B.; Banerjee, S.; Berger, E. L.; Chertok, M.; de Campos, F.; Dedes, A. et al.
Object Type: Article
System: The UNT Digital Library
Parallel-Plate Electrostatic Dual Mass Oscillator (open access)

Parallel-Plate Electrostatic Dual Mass Oscillator

A surface-micromachined two-degree-of-freedom system that was driven by parallel-plate actuation at antiresonance was demonstrated. The system consisted of an absorbing mass connected by folded springs to a drive mass. The system demonstrated substantial motion amplification at antiresonance. The absorber mass amplitudes were 0.8-0.85 pm at atmospheric pressure while the drive mass amplitudes were below 0.1 pm. Larger absorber mass amplitudes were not possible because of spring softening in the drive mass springs. Simple theory of the dual-mass oscillator has indicated that the absorber mass may be insensitive to limited variations in strain and damping. This needs experimental verification. Resonant and antiresonant frequencies were measured and compared to the designed values. Resonant frequency measurements were difficult to compare to the design calculations because of time-varying spring softening terms that were caused by the drive configuration. Antiresonant frequency measurements were close to the design value of 5.1 kHz. The antiresonant frequency was not dependent on spring softening. The measured absorber mass displacement at antiresonance was compared to computer simulated results. The measured value was significantly greater, possibly due to neglecting fringe fields in the force expression used in the simulation.
Date: July 22, 1999
Creator: Allen, James J.; Dyck, Christopher W. & Huber, Robert J.
Object Type: Article
System: The UNT Digital Library
Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. [Quarterly] report, January 1--March 31, 1994 (open access)

Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. [Quarterly] report, January 1--March 31, 1994

The objective of this project is to develop a comprehensive, interdisciplinary, quantitative characterization of a fluvial-deltaic reservoir which will allow realistic interwell and reservoir-scale modeling to be used for improved oil-field development in similar reservoirs world wide. The geological and petrophysical properties of the Cretaceous Ferron Sandstone in east-central Utah will be quantitatively determined. Both new and existing data will be integrated into a 3-D representation of spatial variations in porosity, storativity, and tensorial rock permeability at a scale appropriate for interwell to regional-scale reservoir simulation. Results could improve reservoir management through proper infill and extension drilling strategies, reduce economic risks, increase recovery from existing oil fields, and provide more reliable reserve calculations. Transfer of the project results to the petroleum industry will be an integral component of the project. The technical progress is divided into several sections corresponding to subtasks outlined in the Regional Stratigraphy Task and the Case Studies Task of the original proposal. The primary objective of the Regional Stratigraphy Task is to provide a more detailed interpretation of the stratigraphy of the Ferron Sandstone outcrop belt from Last Chance Creek to Ferron Creek. The morphological framework established from the case studies will be used to generate …
Date: April 22, 1994
Creator: Allison, M. L.
Object Type: Report
System: The UNT Digital Library
Sub-Microsecond Decay Time Phosphors for Pressure Sensitive Paint Applications (open access)

Sub-Microsecond Decay Time Phosphors for Pressure Sensitive Paint Applications

The results suggest that garnet phosphors can be engineered to function thermographically over desired temperature ranges by adjusting gallium content. Substituting gadolinium for the yttrium in the host matrix also has an effect but it is not as large. A silicate phosphor showed the greatest temperature dependence though it could not be excited to fluoresce by a blue LED. All the garnet phosphors could be excited with such a blue source. Two phosphors tested showed an increase in intensity with temperature. Other garnet and silicate materials as mentioned above will be tested in the future. In addition, some perovskite phosphors, such as GdAlO{sub 3}:Ce, will also be investigated.
Date: March 22, 2001
Creator: Allison, S.W.
Object Type: Article
System: The UNT Digital Library
Observation of the moon shadow in deep underground muon flux. (open access)

Observation of the moon shadow in deep underground muon flux.

A shadow of the moon, with a statistical significance of 5{sigma}, has been observed in the underground muon flux at a depth of 2090 mwe using the Soudan 2 detector. The angular resolution of the detector is well described by a Gaussian with {sigma} {le}0.3{degree}. The position of the shadow confirms the alignment of the detector to better than 0.15{degree}. This alignment has remained stable during 10 years of data taking from 1989 through 1998.
Date: June 22, 1999
Creator: Allison, W. W. M.; Alner, G. J.; Ayres, D. S.; Cobb, J. H.; Fields, T. H.; Goodman, M. C. et al.
Object Type: Article
System: The UNT Digital Library
DUSTRAN 1.0 User’s Guide: A GIS-Based Atmospheric Dust Dispersion Modeling System (open access)

DUSTRAN 1.0 User’s Guide: A GIS-Based Atmospheric Dust Dispersion Modeling System

The U.S. Department of Energy’s Pacific Northwest National Laboratory just completed a multi-year project to develop a fully tested and documented atmospheric dispersion modeling system (DUST TRANsport or DUSTRAN) to assist the U.S. Department of Defense in addressing particulate air quality issues at military training and testing ranges. This manual documents the DUSTRAN modeling system and includes installation instructions, a user’s guide, and detailed example tutorials.
Date: September 22, 2006
Creator: Allwine, K Jerry; Rutz, Frederick C.; Shaw, William J.; Rishel, Jeremy P.; Fritz, Brad G.; Chapman, Elaine G. et al.
Object Type: Report
System: The UNT Digital Library
Interaction of intense heavy ion beams with various targets (open access)

Interaction of intense heavy ion beams with various targets

Recently it has been proposed that heavy ion beams could be accelerated with sufficient power and focus to generate shock heating and create hot plasmas in targets of various materials. This preliminary study addresses two aspects of this process: first, the energy deposition by the primary beam, and second, the problem of energy deposition by secondary nuclear reaction particles. For the purpose of discussion it is assumed that beams of 600 MeV/amu uranium (143 GeV total) are focussed on various targets of thickness 1-10 mm. The energy deposition within such targets by the primary and secondary particles is studied.
Date: July 22, 1976
Creator: Alonso, C.
Object Type: Report
System: The UNT Digital Library
GAMMA DETECTOR RESPONSE/SOIL CONCENTRATION CORRELATION STUDY AT THE AAR MANUFACTURING, INC. SITE, LIVONIA, MICHIGAN (open access)

GAMMA DETECTOR RESPONSE/SOIL CONCENTRATION CORRELATION STUDY AT THE AAR MANUFACTURING, INC. SITE, LIVONIA, MICHIGAN

At the NRC�s request, ORAU conducted surveys of the AAR Manufacturing site during the period of September 25 through September 27, 2012. The survey activities included walkover surveys and sampling activities. Once the survey team was onsite, the NRC personnel decided to forgo survey activities in the �New Addition� and the pickling area. Areas of the planned study boundary were inaccessible due to overgrowth/large pieces of concrete covering the soil surface; therefore, the study boundary was redefined. Gamma walkover scans of the site boundary and �front yard� identified multiple areas of elevated gamma radiation. As a result, two judgmental samples were collected. Sample results were above thorium background levels The answer to the PSQ relating to the relationship between thorium concentration in soil and NaI instrument response is �Yes.� NaI instrument response can be used as a predictor of Th-232 concentration in the 0 to 1 m layer. An R2 value of 0.79 was determined for the surface soil relationship, thus satisfying the DQOs. Moreover, the regression was cross-checked by comparing the predicted Th-232 soil core concentration to the average Th-232 concentration (Section 5.3.2). Based on the cross-check, the regression equation provides a reasonable estimate for the Th-232 concentration at …
Date: March 22, 2013
Creator: Altic, Nick A.
Object Type: Report
System: The UNT Digital Library
US DOE and Polish Institute for Ecology of Industrial Areas JCCES FY01 Annual Report (open access)

US DOE and Polish Institute for Ecology of Industrial Areas JCCES FY01 Annual Report

The project Production Scale Implementation of a Petroleum Contaminated Soils Bioreactor was launched in FY00 and showed that bioremediation can be performed under strictly controlled conditions. Initial results showed a 50 percent reduction of total petroleum hydrocarbon concentration in soil from the Czechowice-Dziedzice refinery. It was determined that changes in the design and construction of the bioreactor could improve system performance.
Date: May 22, 2002
Creator: Altman, D. J.
Object Type: Report
System: The UNT Digital Library
A Hydrologic-geophysical Method for Characterizing Flow and Transport Processes Within The Vadose Zone (open access)

A Hydrologic-geophysical Method for Characterizing Flow and Transport Processes Within The Vadose Zone

The primary purpose of this project was to employ two geophysical imaging techniques, electrical resistivity tomography and cross-borehole ground penetrating radar, to image a controlled infiltration of a saline tracer under unsaturated flow conditions. The geophysical techniques have been correlated to other more traditional hydrologic measurements including neutron moisture measurements and induction conductivity logs. Images that resulted during two successive infiltrations indicate the development of what appear to be preferential pathways through the finer grained materials, although the results could also be produced by cationic capture of free ions in clays. In addition the site as well as the developing solute plume exhibits electrical anisotropy which is likely related to flow properties. However the geologic significance of this phenomenon is still under investigation.
Date: January 22, 2004
Creator: Alumbaugh, David; LaBrecque, Douglas; Brainard, James & Yeh, T.C. (Jim)
Object Type: Report
System: The UNT Digital Library
Reach the Bottom Line of the Sbottom Search (open access)

Reach the Bottom Line of the Sbottom Search

We propose a new search strategy for directly-produced sbottoms at the LHC with a small mass splitting between the sbottom and its decayed stable neutralino. Our search strategy is based on boosting sbottoms through an energetic initial state radiation jet. In the final state, we require a large missing transverse energy and one or two b-jets besides the initial state radiation jet. We also define a few kinematic variables to further increase the discovery reach. For the case that the sbottom mainly decays into the bottom quark and the stable neutralino, we have found that even for a mass splitting as small as 10 GeV sbottoms with masses up to around 400 GeV can be excluded at the 95% confidence level with 20 inverse femtobarn data at the 8 TeV LHC.
Date: May 22, 2012
Creator: Alvarez, Ezequiel & Bai, Yang
Object Type: Article
System: The UNT Digital Library
Composite Inelastic Dark Matter (open access)

Composite Inelastic Dark Matter

None
Date: November 22, 2011
Creator: Alves, Daniele S. M.; Behbahani, Siavosh R.; Schuster, Philip & Wacker, Jay G.
Object Type: Article
System: The UNT Digital Library
Model-Independent Jets plus Missing Energy Searches (open access)

Model-Independent Jets plus Missing Energy Searches

We present a proposal for performing model-independent jets plus missing energy searches. Currently, these searches are optimized for mSUGRA and are consequently not sensitive to all kinematically-accessible regions of parameter space. We show that the reach of these searches can be broadened by setting limits on the differential cross section as a function of the total visible energy and the missing energy. These measurements only require knowledge of the relevant Standard Model backgrounds and can be subsequently used to limit any theoretical model of new physics. We apply this approach to an example where gluinos are pair-produced and decay to the LSP through a single-step cascade, and show how sensitivity to different gluino masses is altered by the presence of the decay chain. The analysis is closely based upon the current searches done at the Tevatron and our proposal requires only small modifications to the existing techniques. We find that within the MSSM, the gluino can be as light as 125 GeV. The same techniques are applicable to jets and missing energy searches at the Large Hadron Collider.
Date: September 22, 2008
Creator: Alwall, Johan; Le, My-Phuong; Lisanti, Mariangela & Wacker, Jay G.
Object Type: Article
System: The UNT Digital Library