1. Mono([8]annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes (open access)

1. Mono([8]annulene)Uranium(4) half-sandwich complexes, 2. Novel syntheses of symmetrically substituted cyclooctatetetraenes

A reproducible, high-yield synthesis of mono([8]annulene)uranium(4)dichloride (1) is reported, along with the X-ray crystal structural of the bis(pyridine) adduct. Metathesis reactions of the half-sandwich complex 1 with a variety of simple alkyl and alkoxy reagents failed to generate any isolable mono-ring complexes. Reactions of 1 with polydentate, delocalized anions did produce stable derivatives, including mono([8]annulene)uranium(4)bis(acetylacetonate) (4). An X-ray crystal structure of 4 is reported.
Date: October 1, 1991
Creator: Boussie, T. R.
System: The UNT Digital Library
Aluminum recovery from coal fly ash by high temperature chlorination (open access)

Aluminum recovery from coal fly ash by high temperature chlorination

A study of aluminum recovery from power plant fly ash by high temperature chlorination was undertaken to demonstrate that fly ash could be a potential source of aluminum, iron and possibly silicon. Magnetic separation of the iron oxide served as a first step to alleviate the iron contamination problem. However, the agglomeration of some iron oxide with alumina and silica made it difficult to completely separate the iron from the fly ash. Further iron separation was achieved by chlorinating the nonmagnetic ash fraction at 550/sup 0/C for 30 minutes. This reduced the iron oxide content to less than 4 percent by weight. Chlorine flow rates affected the reaction rate much more drastically than temperatures. This suggested that diffusion was the major rate-controlling step. Besides Fe/sub 2/O/sub 3/, Al/sub 2/O/sub 3/ and SiO/sub 2/, other oxides such as CaO, K/sub 2/O, Na/sub 2/O and MgO might have complicated the alumina recovery by forming individual chlorides or complexes. Investigating methods for separating more Fe/sub 2/O/sub 3/, and possibly CaO, K/sub 2/O, Na/sub 2/O and MgO from the nonmagnetic ash fraction before chlorinating it is highly recommended.
Date: October 1, 1977
Creator: Wijatno, H.
System: The UNT Digital Library
Anodic oxygen-transfer electrocatalysis at iron-doped lead dioxide electrodes (open access)

Anodic oxygen-transfer electrocatalysis at iron-doped lead dioxide electrodes

The research illustrated in this thesis was performed under the guidance of Professor Dennis C. Johnson beginning in March 1987. Chapter 2 concentrates on the development and electrocatalytic properties of iron-doped {beta}-PbO{sub 2} films on noble-metal substrates. Chapter 3 focuses attention on the preparation and characterization of iron-doped {beta}-PbO{sub 2} films on titanium substrates (Fe-PbO{sub 2}/Ti). Chapter 4 discusses anodic evolution of ozone at Fe-PbO{sub 2}/Ti electrodes. Chapter 5 describes electrochemical incineration of p-benzoquinone (BQ) at Fe-PbO{sub 2}/Ti electrodes. In addition, the Appendix includes another published paper which is a detailed study of {alpha}-PbO{sub 2} films deposited on various types of stainless steel substrates.
Date: October 1, 1994
Creator: Feng, Jianren
System: The UNT Digital Library
Application of Soft X-Ray Appearance Potential Spectroscopy to Light Lanthanides, 4d Transition Metals, and Insulators (open access)

Application of Soft X-Ray Appearance Potential Spectroscopy to Light Lanthanides, 4d Transition Metals, and Insulators

Evaporated films of La, Ce, Yb, Y, Ag--Mn(5 percent), KCl, MnF$sub 2$, CsCl and LaF$sub 3$ were studied using the soft x-ray appearance potential spectroscopy (SXAPS) technique. Studies were also made of bulk polycrystalline samples of Y, Zr, Nb, and Mo. The results are discussed in terms of existing SXAPS theories. Several similarities between soft x-ray absorption (SXA) data and the SXAPS results are discussed, and it is shown that the SXA data can aid in the interpretation of SXAPS spectra when using the well-known self-convolution model. In this approximation the absorption coefficient, $alpha$(E), is substituted for the density of states, N(E-E/sub c/) $Yields$ $alpha$(E). For more localized excitations, a convolution of $alpha$(E) with bremsstrahlung isochromat data, based on Wendin's two density of states formalism is used to predict SNAPS results. (auth)
Date: October 1, 1975
Creator: Smith, R. J.
System: The UNT Digital Library
B Quark Tagging and Cross-Section Measurement in Quark Pair Production at d0 (open access)

B Quark Tagging and Cross-Section Measurement in Quark Pair Production at d0

None
Date: October 1, 2004
Creator: Greder, Sebastien & /Louis Pasteur U., Strasbourg I /Strasbourg, IReS
System: The UNT Digital Library
B-tagging and the search for neutral supersymmetric Higgs bosons at D0 (open access)

B-tagging and the search for neutral supersymmetric Higgs bosons at D0

A search for neutral supersymmetric Higgs bosons and work relating to the improvement of the b-tagging and trigger capabilities at the D0 detector during Run II of the Fermilab Tevatron collider is presented. The search for evidence of the Higgs sector in the Standard Model (SM) and supersymmetric extensions of the SM are a high priority for the D0 collaboration, and b-tagging and good triggers are a vital component of these searches. The development and commissioning of the first triggers at D0 which use b-tagging is outlined, along with the development of a new secondary vertex b-tagging tool for use in the Level 3 trigger. Upgrades to the Level 3 trigger hit finding code, which have led to significant improvements in the quality and efficiency of the tracking code, and by extension the b-tagging tools, are also presented. An offline Neural Network (NN) b-tagging tool was developed, trained on Monte Carlo and extensively tested and measured on data. The new b-tagging tool significantly improves the b-tagging performance at D0, for a fixed fake rate relative improvements in signal efficiency range from {approx} 40% to {approx} 15%. Fake rates, for a fixed signal efficiency, are typically reduced to between a quarter …
Date: October 1, 2006
Creator: Scanlon, Tim
System: The UNT Digital Library
Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho (open access)

Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho

A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an idealized basalt lava flow model was generated that used a set of nomenclature that would be standard for the basalt lava flows studied. An upper vesicular zone, a sometimes absent columnar zone, central zone, and lower vesicular zone make up the basalt lava flow model. The overall distinction between the different zones are based on the vesicle shape size, vesicularity, and fractures present. The results of the studies also indicated that the basalt lava flows at the INEL are distal to medial facies pahoehoe lava flows with close fitting contacts. The most permeable zones identified in these basalts are fractured vesiculated portions of the top of the lava flow, the columnar areas, and basalt-flow contacts in order of importance. …
Date: October 1, 1996
Creator: Bennecke, William M.
System: The UNT Digital Library
Broadband Excitation in Nuclear Magnetic Resonance (open access)

Broadband Excitation in Nuclear Magnetic Resonance

Theoretical methods for designing sequences of radio frequency (rf) radiation pulses for broadband excitation of spin systems in nuclear magnetic resonance (NMR) are described. The sequences excite spins uniformly over large ranges of resonant frequencies arising from static magnetic field inhomogeneity, chemical shift differences, or spin couplings, or over large ranges of rf field amplitudes. Specific sequences for creating a population inversion or transverse magnetization are derived and demonstrated experimentally in liquid and solid state NMR. One approach to broadband excitation is based on principles of coherent averaging theory. A general formalism for deriving pulse sequences is given, along with computational methods for specific cases. This approach leads to sequences that produce strictly constant transformations of a spin system. The importance of this feature in NMR applications is discussed. A second approach to broadband excitation makes use of iterative schemes, i.e. sets of operations that are applied repetitively to a given initial pulse sequences, generating a series of increasingly complex sequences with increasingly desirable properties. A general mathematical framework for analyzing iterative schemes is developed. An iterative scheme is treated as a function that acts on a space of operators corresponding to the transformations produced by all possible pulse sequences. …
Date: October 1, 1984
Creator: Tycko, R.
System: The UNT Digital Library
Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst (open access)

Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst

Carbon monoxide oxidation was performed over the three different oxidation states of copper -- metallic (Cu), copper (I) oxide (Cu{sub 2}O), and copper (II) oxide (CuO) as a test case for developing a model metal oxide catalyst amenable to study by the methods of modern surface science and catalysis. Copper was deposited and oxidized on oxidized supports of aluminum, silicon, molybdenum, tantalum, stainless steel, and iron as well as on graphite. The catalytic activity was found to decrease with increasing oxidation state (Cu > Cu{sub 2}O > CuO) and the activation energy increased with increasing oxidation state (Cu, 9 kcal/mol < Cu{sub 2}O, 14 kcal/mol < CuO, 17 kcal/mol). Reaction mechanisms were determined for the different oxidation states. Lastly, NO reduction by CO was studied. A Cu and CuO catalyst were exposed to an equal mixture of CO and NO at 300--350 C to observe the production of N{sub 2} and CO{sub 2}. At the end of each reaction, the catalyst was found to be Cu{sub 2}O. There is a need to study the kinetics of this reaction over the different oxidation states of copper.
Date: October 1, 1994
Creator: Jernigan, G. G.
System: The UNT Digital Library
Characterization and analytical application of an $alpha$-hydroxy oxime resin for chromatography (open access)

Characterization and analytical application of an $alpha$-hydroxy oxime resin for chromatography

None
Date: October 1, 1974
Creator: Goodkin, L.
System: The UNT Digital Library
Characterization and application of microearthquake clusters to problems of scaling, fault zone dynamics, and seismic monitoring at Parkfield, California (open access)

Characterization and application of microearthquake clusters to problems of scaling, fault zone dynamics, and seismic monitoring at Parkfield, California

This document contains information about the characterization and application of microearthquake clusters and fault zone dynamics. Topics discussed include: Seismological studies; fault-zone dynamics; periodic recurrence; scaling of microearthquakes to large earthquakes; implications of fault mechanics and seismic hazards; and wave propagation and temporal changes.
Date: October 1, 1995
Creator: Nadeau, R. M.
System: The UNT Digital Library
Characterization and refinement of carbide coating formation rates and dissolution kinetics in the Ta-C system (open access)

Characterization and refinement of carbide coating formation rates and dissolution kinetics in the Ta-C system

The interaction between carbide coating formation rates and dissolution kinetics in the tantalum-carbon system was investigated. The research was driven by the need to characterize carbide coating formation rates. The characterization of the carbide coating formation rates was required to engineer an optimum processing scheme for the fabrication of the ultracorrosion-resistant composite, carbon-saturated tantalum. A packed-bed carburization process was successfully engineered and employed. The packed-bed carburization process produced consistent, predictable, and repeatable carbide coatings. A digital imaging analysis measurement process for accurate and consistent measurement of carbide coating thicknesses was developed. A process for removing the chemically stable and extremely hard tantalum-carbide coatings was also developed in this work.
Date: October 1, 1996
Creator: Rodriguez, P.J.
System: The UNT Digital Library
Chemical shift anisotropies of /sup 1/H in H/sub 2/O(s), H/sub 2/S(s), and C/sub 6/H/sub 6/(s) (open access)

Chemical shift anisotropies of /sup 1/H in H/sub 2/O(s), H/sub 2/S(s), and C/sub 6/H/sub 6/(s)

The proton NMR in powdered samples of H/sub 2/O(s), H/sub 2/S(s), and C/sub 6/H/sub 6/(s) have been studied by multiple pulse line narrowing techniques. The resultant spectra provide nuclear magnetic shielding tensors that are (at least approximately) axially symmetric. The anisotropy is 34.2 +- 1.0 ppM for ice, 11.1 +- 1.0 ppM for the highest-temperature phase of solid hydrogen sulfide, and -5.3 +- 0.3 for benzene. Comparisons are made with previous experimental and theoretical work.
Date: October 1, 1977
Creator: Ryan, L. M.
System: The UNT Digital Library
Chemiluminescent detection of metals in liquid chromatography (open access)

Chemiluminescent detection of metals in liquid chromatography

None
Date: October 1, 1974
Creator: Strom, B.M.
System: The UNT Digital Library
[Chemistry Thesis] Part 1: The Spectra of Some Aliphatic Aldehydes and Their Monodeutero Derivatives, (open access)

[Chemistry Thesis] Part 1: The Spectra of Some Aliphatic Aldehydes and Their Monodeutero Derivatives,

BS>An investigation of the infrared and near-ultraviolet spectra of three aliphatic aldchydes and their monodeutero derivatives is described. The infrared spectra of the acetaldehydes (CH/sub 3/CHO and CH/sub 3/CDO) were in agreement with work reported recently. A few new bands are reported and discussed. The infrared spectra of C/sub 2/H/sub 5/CHO, C/sub 2/H/sub 5/CDO, C/ sub 3/H/sub 7/CHO, and C/sub 3/H/sub 7/CDO at 450 to 4000 cm/sup -1/ were observed, and an assignment of the observed bands was made. The weak absorption of the aliphatic aldehydes which extends from lambda 3500 A to lambda 2300 A was investigated. The strength of the absorption (f-value) is decreased by deuterium substitution at the aldehyde CHO group. The decrease in the f-value can be accounted for by the theory of vibrationally induced electronic transitions. The effect of isotopic substitution on the intensity of symmetry- allowed as well as synnmetryforbidden (vibrationally allowed) electronic transitions in polyatomic molecules is discussed. (auth)
Date: October 1, 1958
Creator: Worden, Earl Fremont, Jr.
System: The UNT Digital Library
Coherence techniques at extreme ultraviolet wavelengths (open access)

Coherence techniques at extreme ultraviolet wavelengths

The renaissance of Extreme Ultraviolet (EUV) and soft x-ray (SXR) optics in recent years is mainly driven by the desire of printing and observing ever smaller features, as in lithography and microscopy. This attribute is complemented by the unique opportunity for element specific identification presented by the large number of atomic resonances, essentially for all materials in this range of photon energies. Together, these have driven the need for new short-wavelength radiation sources (e.g. third generation synchrotron radiation facilities), and novel optical components, that in turn permit new research in areas that have not yet been fully explored. This dissertation is directed towards advancing this new field by contributing to the characterization of spatial coherence properties of undulator radiation and, for the first time, introducing Fourier optical elements to this short-wavelength spectral region. The first experiment in this dissertation uses the Thompson-Wolf two-pinhole method to characterize the spatial coherence properties of the undulator radiation at Beamline 12 of the Advanced Light Source. High spatial coherence EUV radiation is demonstrated with appropriate spatial filtering. The effects of small vertical source size and beamline apertures are observed. The difference in the measured horizontal and vertical coherence profile evokes further theoretical studies on …
Date: October 1, 2002
Creator: Chang, Chang
System: The UNT Digital Library
Collision dynamics of methyl radicals and highly vibrationally excited molecules using crossed molecular beams (open access)

Collision dynamics of methyl radicals and highly vibrationally excited molecules using crossed molecular beams

The vibrational to translational (V{yields}T) energy transfer in collisions between large highly vibrationally excited polyatomics and rare gases was investigated by time-of-flight techniques. Two different methods, UV excitation followed by intemal conversion and infrared multiphoton excitation (IRMPE), were used to form vibrationally excited molecular beams of hexafluorobenzene and sulfur hexafluoride, respectively. The product translational energy was found to be independent of the vibrational excitation. These results indicate that the probability distribution function for V{yields}T energy transfer is peaked at zero. The collisional relaxation of large polyatomic molecules with rare gases most likely occurs through a rotationally mediated process. Photodissociation of nitrobenzene in a molecular beam was studied at 266 nm. Two primary dissociation channels were identified including simple bond rupture to produce nitrogen dioxide and phenyl radical and isomerization to form nitric oxide and phenoxy radical. The time-of-flight spectra indicate that simple bond rupture and isomerization occurs via two different mechanisms. Secondary dissociation of the phenoxy radicals to carbon monoxide and cyclopentadienyl radicals was observed as well as secondary photodissociation of phenyl radical to give H atom and benzyne. A supersonic methyl radical beam source is developed. The beam source configuration and conditions were optimized for CH{sub 3} production from …
Date: October 1, 1991
Creator: Chu, P. M. Y.
System: The UNT Digital Library
Condensation of Metal Vapors: Mercury and the Kinetic Theory of Condensation (open access)

Condensation of Metal Vapors: Mercury and the Kinetic Theory of Condensation

None
Date: October 1, 1964
Creator: Wilhelm, D. J.
System: The UNT Digital Library
Constructing Predictive Estimates for Worker Exposure to Radioactivity During Decommissioning: Analysis of Completed Decommissioning Projects (open access)

Constructing Predictive Estimates for Worker Exposure to Radioactivity During Decommissioning: Analysis of Completed Decommissioning Projects

An analysis of completed decommissioning projects is used to construct predictive estimates for worker exposure to radioactivity during decommissioning activities. The preferred organizational method for the completed decommissioning project data is to divide the data by type of facility, whether decommissioning was performed on part of the facility or the complete facility, and the level of radiation within the facility prior to decommissioning (low, medium, or high). Additional data analysis shows that there is not a downward trend in worker exposure data over time. Also, the use of a standard estimate for worker exposure to radioactivity may be a best estimate for low complete storage, high partial storage, and medium reactor facilities; a conservative estimate for some low level of facility radiation facilities (reactor complete, research complete, pits/ponds, other), medium partial process facilities, and high complete research facilities; and an underestimate for the remaining facilities. Limited data are available to compare different decommissioning alternatives, so the available data are reported and no conclusions can been drawn. It is recommended that all DOE sites and the NRC use a similar method to document worker hours, worker exposure to radiation (person-rem), and standard industrial accidents, injuries, and deaths for all completed decommissioning …
Date: October 1, 2002
Creator: Dettmers, Dana Lee & Eide, Steven Arvid
System: The UNT Digital Library
Crystal and molecular structure of organophosphorus insecticides (open access)

Crystal and molecular structure of organophosphorus insecticides

The crystal and molecular structures of the following organophosphorus (OP) insecticides have been determined by three-dimensional X-ray analysis: ronnel (0,0-dimethyl 0-2,4,5 trichlorophenyl phosphorothioate), ronnel oxon (0,0-dimethyl 0-2,4,5 trichlorophenyl phosphate), bomophos (0-(4-bromo-2,5-dichlorophenyl) 0,0-dimethyl phosphorothioate), Ruelene (0-(4-tert-Butyl-2-chlorophenyl)-0-methyl-N-methyl phosphoroamidate), fospirate (0,0-dimethyl 0-3,5,6-trichloro-2-pyridyl phosphate) and chlorpyrifos (0,0-diethyl 0-3,5,6-trichloro-2-pyridyl phosphorothioate). Phosphorus to meta hydrogen distances for the respective compounds are: 5.51, 5.49, 5.42, (5.68, 5.13), 5.79 and 5.78 A. All of these distances fall well within the range of literature values cited for the intramolecular active site-separation distance for insect acetylcholinesterase (AChE), yet are well outside that for mammalian AChE. In addition the crystal structure of ronnel displays a hydrogen-sulfur intermolecular interaction in the b direction and a phosphorus which is readily accessible for phosphorylation of AChE. The structure of ronnel oxon is quite similar to that of ronnel. CNDO 11 molecular orbital calculations are presented to show the charge distribution in the compound. A likely intramolecular hydrogen bond in bromophos restricts rotation about the phenolic C-O bond. The configuration of Ruelene is substantiated by CNDO 11 molecular orbital calculations and van der Waals arguments and features a possible weak intramolecular hydrogen bond which somewhat restricts rotation about the phenolic C-O bond. Charge density information …
Date: October 1, 1977
Creator: Baughman, R. G.
System: The UNT Digital Library
Determination of Vapor-Liquid Equilibrium Data and Decontamination Factors Needed for the Development of Evaporator Technology for Use in Volume Reduction of Radioactive Waste Streams (open access)

Determination of Vapor-Liquid Equilibrium Data and Decontamination Factors Needed for the Development of Evaporator Technology for Use in Volume Reduction of Radioactive Waste Streams

A program is currently in progress at Argonne National Laboratory to evaluate and develop evaporator technology for concentrating radioactive waste streams. By concentrating radioactive waste streams, disposal costs can be significantly reduced. To effectively reduce the volume of waste, the evaporator must achieve high decontamination factors so that the distillate is sufficiently free of radioactive material. One technology that shows a great deal of potential for this application is being developed by LICON, Inc. In this program, Argonne plans to apply LICON`s evaporator designs to the processing of radioactive solutions. Concepts that need to be incorporated into the design of the evaporator include, criticality safety, remote operation and maintenance, and materials of construction. To design an effective process for concentrating waste streams, both solubility and vapor-liquid equilibrium data are needed. The key issue, however, is the high decontamination factors that have been demonstrated by this equipment. Two major contributions were made to this project. First, a literature survey was completed to obtain available solubility and vapor-liquid equilibrium data. Some vapor-liquid data necessary for the project but not available in the literature was obtained experimentally. Second, the decontamination factor for the evaporator was determined using neutron activation analysis (NAA).
Date: October 1, 1993
Creator: Betts, S. E.
System: The UNT Digital Library
Deuteron nuclear magnetic resonance investigation of LaNi$sub 5$D/sub x/ compounds (open access)

Deuteron nuclear magnetic resonance investigation of LaNi$sub 5$D/sub x/ compounds

The $sup 2$D quadrupole interaction was observable in all the samples of LaNi$sub 5$D/sub x/ up to a critical temperature T/sub c/ at which the intensity of the quadrupole interaction spectrum disappeared and only a narrow unsplit line remained. The critical temperatures were 360$sup 0$K for the x = 3.6 sample and 380$sup 0$K for the x = 5.7, 6.7 samples. Based on preliminary electric field gradient (EFG) calculations, it appears likely that several quadrupole interactions are being observed from inequivalent deuterium sites in the lattice. In the temperature range T greater than or equal to 300$sup 0$K, it appears that diffusional averaging is not entirely isotropic and that the deuterium still occupies certain interstitial sites preferentially. The temperature dependence of the $sup 2$D characteristic quadrupole frequency ($nu$/sub Q/) and the disappearance of the $sup 2$D quadrupole interaction signal were found to be compatible with desorption of the deuterium from the LaNi$sub 5$ lattice with increasing temperature. Spectra obtained from D$sub 2$ gas samples under various experimental conditions (pure gas, gas above LaNi$sub 5$D$sub 6$.$sub 7$, and gas within or on LaNi$sub 5$ at 77$sup 0$K) may provide evidence for the identification of the solid-solution $alpha$-phase or for the existence …
Date: October 1, 1975
Creator: Nelson, S.O.
System: The UNT Digital Library
DEVELOPMENT OF A FLUOROSCOPE FOR STUDYING TWO-PHASE FLOW PATTERNS (open access)

DEVELOPMENT OF A FLUOROSCOPE FOR STUDYING TWO-PHASE FLOW PATTERNS

None
Date: October 1, 1964
Creator: Johanns, J.
System: The UNT Digital Library
Di-J/psi Studies, Level 3 Tracking and the D0 Run IIb Upgrade (open access)

Di-J/psi Studies, Level 3 Tracking and the D0 Run IIb Upgrade

The D0 detector underwent an upgrade to its silicon vertex detector and triggering systems during the transition from Run IIa to Run IIb to maximize its ability to fully exploit Run II at the Fermilab Tevatron. This thesis describes improvements made to the tracking and vertexing algorithms used by the high level trigger in both Run IIa and Run IIb, as well as a search for resonant di-J/{psi} states using both Run IIa and Run IIb data. Improvements made to the tracking and vertexing algorithms during Run IIa included the optimization of the existing tracking software to reduce overall processing time and the certification and testing of a new software release. Upgrades made to the high level trigger for Run IIb included the development of a new tracking algorithm and the inclusion of the new Layer 0 silicon detector into the existing software. The integration of Layer 0 into the high level trigger has led to an improvement in the overall impact parameter resolution for tracks of {approx}50%. The development of a new parameterization method for finding the error associated to the impact parameter of tracks returned by the high level tracking algorithm, in association with the inclusion of Layer …
Date: October 1, 2009
Creator: Vint, Philip John
System: The UNT Digital Library