Two-Photon Interactions with Nuclear Breakup in Relativistic Heavy Ion Collisions (open access)

Two-Photon Interactions with Nuclear Breakup in Relativistic Heavy Ion Collisions

Highly charged relativistic heavy ions have high cross-sections for two-photon interactions. The photon flux is high enough that two-photon interactions may be accompanied by additional photonuclear interactions. Except for the shared impact parameter, these interactions are independent. Additional interactions like mutual Coulomb excitation are of experimental interest, since the neutrons from the nuclear dissociation provide a simple, relatively unbiased trigger. We calculate the cross sections, rapidity, mass and transverse momentum (p{sub T}) distributions for exclusive {gamma}{gamma} production of mesons and lepton pairs, and for {gamma}{gamma} reactions accompanied by mutual Coulomb dissociation. The cross-sections for {gamma}{gamma} interactions accompanied by multiple neutron emission (XnXn) and single neutron emission (1n1n) are about 1/10 and 1/100 of that for the unaccompanied {gamma}{gamma} interactions. We discuss the accuracy with which these cross-sections may be calculated. The typical p{sub T} of {gamma}{gamma} final states is several times smaller than for comparable coherent photonuclear interactions, so p{sub T} may be an effective tool for separating the two classes of interactions.
Date: July 7, 2010
Creator: Baltz, Anthony J.; Gorbunov, Yuri; R Klein, Spencer & Nystrand, Joakim
Object Type: Article
System: The UNT Digital Library
Kinase Expression and Chromosomal Rearrangements in Papillary Thyroid Cancer Tissues: Investigations at the Molecular and Microscopic Levels (open access)

Kinase Expression and Chromosomal Rearrangements in Papillary Thyroid Cancer Tissues: Investigations at the Molecular and Microscopic Levels

Structural chromosome aberrations are known hallmarks of many solid tumors. In the papillary form of thyroid cancer (PTC), for example, activation of the receptor tyrosine kinase (RTK) genes, ret or the neurotrophic tyrosine kinase receptor type I (NTRK1) by intra- or interchromosomal rearrangements have been suggested as a cause of the disease. The 1986 accident at the nuclear power plant in Chernobyl, USSR, led to the uncontrolled release of high levels of radioisotopes. Ten years later, the incidence of childhood papillary thyroid cancer (chPTC) near Chernobyl had risen by two orders of magnitude. Tumors removed from some of these patients showed aberrant expression of the ret RTK gene due to a ret/PTC1 or ret/PTC3 rearrangement involving chromosome 10. However, many cultured chPTC cells show a normal G-banded karyotype and no ret rearrangement. We hypothesize that the 'ret-negative' tumors inappropriately express a different oncogene or have lost function of a tumor suppressor as a result of chromosomal rearrangements, and decided to apply molecular and cytogenetic methods to search for potentially oncogenic chromosomal rearrangements in Chernobyl chPTC cases. Knowledge of the kind of genetic alterations may facilitate the early detection and staging of chPTC as well as provide guidance for therapeutic intervention.
Date: July 7, 2009
Creator: Weier, Heinz-Ulrich; Kwan, Johnson; Lu, Chun-Mei; Ito, Yuko; Wang, Mei; Baumgartner, Adolf et al.
Object Type: Report
System: The UNT Digital Library
Nonlinear Flow Generation By Electrostatic Turbulence In Tokamaks (open access)

Nonlinear Flow Generation By Electrostatic Turbulence In Tokamaks

Global gyrokinetic simulations have revealed an important nonlinear flow generation process due to the residual stress produced by electrostatic turbulence of ion temperature gradient (ITG) modes and trapped electron modes (TEM). In collisionless TEM (CTEM) turbulence, nonlinear residual stress generation by both the fluctuation intensity and the intensity gradient in the presence of broken symmetry in the parallel wave number spectrum is identified for the first time. Concerning the origin of the symmetry breaking, turbulence self-generated low frequency zonal flow shear has been identified to be a key, universal mechanism in various turbulence regimes. Simulations reported here also indicate the existence of other mechanisms beyond E × B shear. The ITG turbulence driven “intrinsic” torque associated with residual stress is shown to increase close to linearly with the ion temperature gradient, in qualitative agreement with experimental observations in various devices. In CTEM dominated regimes, a net toroidal rotation is driven in the cocurrent direction by “intrinsic” torque, consistent with the experimental trend of observed intrinsic rotation. The finding of a “flow pinch” in CTEM turbulence may offer an interesting new insight into the underlying dynamics governing the radial penetration of modulated flows in perturbation experiments. Finally, simulations also reveal highly …
Date: July 7, 2010
Creator: Wang, W. X.; Diamond, P. H.; Hahm, T. S.; Ethier, S.; Rewoldt, G. & Tang, W. M.
Object Type: Report
System: The UNT Digital Library
Initial Eccentricity in Deformed 197Au+197Au and 238U+238U Collisions at RHIC (open access)

Initial Eccentricity in Deformed 197Au+197Au and 238U+238U Collisions at RHIC

Initial eccentricity and eccentricity fluctuations of the interaction volume created in relativistic collisions of deformed {sup 197}Au and {sup 238}U nuclei are studied using optical and Monte-Carlo (MC) Glauber simulations. It is found that the non-sphericity noticeably influences the average eccentricity in central collisions and eccentricity fluctuations are enhanced due to deformation. Quantitative results are obtained for Au+Au and U+U collisions at energy {radical}s{sub NN} = 200 GeV.
Date: July 7, 2010
Creator: Filip, Peter; Lednicky, Richard; Masui, Hiroshi & Xu, Nu
Object Type: Article
System: The UNT Digital Library
The Shifting Landscape of Ratepayer-Funded Energy Efficiency in the U.S. (open access)

The Shifting Landscape of Ratepayer-Funded Energy Efficiency in the U.S.

None
Date: July 7, 2009
Creator: Barbose, G.; Goldman, C. & Schlegel, J.
Object Type: Article
System: The UNT Digital Library
High pressure phase transformation in iron under fast compression (open access)

High pressure phase transformation in iron under fast compression

We present experimental results on the solid-solid, {alpha} to {epsilon} phase transformation kinetics of iron under high pressure dynamic compression. We observe kinetic features - velocity loops - similar with the ones recently reported to occur when water is frozen into its ice VII phase under comparable experimental conditions. We analyze this behavior in terms of general ideas coupling the steady sample compression with phase nucleation and growth with a pressure dependent phase interface velocity. The model is used to predict the response of iron when steadily driven across the {alpha} - {epsilon} phase boundary on very short time scales, including those envisioned to be achieved in ultra-fast laser experiments.
Date: July 7, 2009
Creator: Bastea, M; Bastea, S & Becker, R
Object Type: Article
System: The UNT Digital Library
Technology Summary Advancing Tank Waste Retreival and Processing (open access)

Technology Summary Advancing Tank Waste Retreival and Processing

This technology overview provides a high-level summary of technologies being investigated and developed by Washington River Protection Solutions (WRPS) to advance Hanford Site tank waste retrieval and processing. Technology solutions are outlined, along with processes and priorities for selecting and developing them.
Date: July 7, 2010
Creator: Sams, T. L.
Object Type: Report
System: The UNT Digital Library
Energy Dependence of High Moments for Net-proton Distributions (open access)

Energy Dependence of High Moments for Net-proton Distributions

High moments of multiplicity distributions of conserved quantities are predicted to be sensitive to critical fluctuations. To understand the effect of the non-critical physics backgrounds on the proposed observable, we have studied various moments of net-proton distributions with AMPT, Hijing, Therminator and UrQMD models, in which no QCD critical point physics is implemented. It is found that the centrality evolution of various moments of net-proton distributions can be uniformly described by a superposition of emission sources. In addition, in the absence of critical phenomena, some moment products of net-proton distributions, related to the baryon number susceptibilities in Lattice QCD calculations, are predicted to be constant as a function of the collision centrality. We argue that a non-monotonic dependence of the moment products as a function of the beam energy may be used to locate the QCD critical point.
Date: July 7, 2010
Creator: Luo, Xiaofeng; Mohanty, Bedangadas; Ritter, Hans Georg & Xu, Nu
Object Type: Article
System: The UNT Digital Library
Tank 38H Saltcake Core and Supernate Sample Analysis (open access)

Tank 38H Saltcake Core and Supernate Sample Analysis

This report provides details of the characterization of Tank 38H saltcake and supernate samples pulled in September 2003. The core sample HTF-E-03-114 contained approximately 4 inches of saltcake, which was soupy and brown with white chunks, and contained less than 15 mL of cloudy free liquid. The undrained bulk saltcake had a water content of 16.8 percentage weight and a bulk density that was approximately 1.94 g/cm3 at full saturation. The 137Cs activity of the bulk saltcake in sample HTF-E-03-114 was 3.72E+7 pCi/g, which corresponds to 0.3 Ci per gallon of saltcake. The 238Pu activity of the bulk saltcake was 3.62E+6 pCi/g. The filtered free liquid in sample HTF-E-03-114 had a density of 1.430 g/cm3, a 137Cs activity of 0.73 Ci/gal., and a 238Pu activity of 5.78E+3 pCi/mL. The solids filtered from the HTF-E-03-114 free liquid were primarily composed of salts (sodium nitrate and sodium carbonate monohydrate) and sodium aluminosilicates. The Tank 38H supernate samples (HTF-E-03-122 and 123) had a density of 1.45 g/cm3, a 137Cs activity of 0.65 Ci/gal, a 238Pu activity of 2.2E4 pCi/mL, and contained no visible insoluble solids. The viscosity of supernate samples HTF-E-03-122 and 123 was determined at 25 degrees Celsius, 35 degrees Celsius, and …
Date: July 7, 2004
Creator: Martino, Christopher J.; Nichols, R. L.; McCabe, D. J. & Hansen, E. K.
Object Type: Report
System: The UNT Digital Library
Prediction of water seepage into a geologic repository for high-level radioactive waste (open access)

Prediction of water seepage into a geologic repository for high-level radioactive waste

Predicting the amount of water that may seep into waste emplacement drifts is important for assessing the performance of the proposed geologic repository for high-level radioactive waste at Yucca Mountain, Nevada. The repository would be located in thick, partially saturated fractured tuff that will be heated to above-boiling temperatures as a result of heat generation from the decay of nuclear waste. Since infiltrating water will be subject to vigorous boiling for a significant time period, the superheated rock zone (i.e., rock temperature above the boiling point of water) can form an effective vaporization barrier that reduces the possibility of water arrival at emplacement drifts. In this paper, we analyze the behavior of episodic preferential flow events that penetrate the hot fractured rock, evaluate the impact of such flow behavior on the effectiveness of the vaporization barrier, and discuss the implications for the performance assessment of the repository. A semi-analytical solution is utilized to determine the complex flow processes in the hot rock environment. The solution is applied at several discrete times after emplacement, covering the time period of strongly elevated temperatures at Yucca Mountain.
Date: July 7, 2003
Creator: Birkholzer, Jens; Mukhophadhyay, Sumit & Tsang, Yvonne
Object Type: Article
System: The UNT Digital Library
Development of lean premixed low-swirl burner for low NO{sub x} practical application (open access)

Development of lean premixed low-swirl burner for low NO{sub x} practical application

Laboratory experiments have been performed to evaluate the performance of a premixed low-swirl burner (LSB) in configurations that simulate commercial heating appliances. Laser diagnostics were used to investigate changes in flame stabilization mechanism, flowfield, and flame stability when the LSB flame was confined within quartz cylinders of various diameters and end constrictions. The LSB adapted well to enclosures without generating flame oscillations and the stabilization mechanism remained unchanged. The feasibility of using the LSB as a low NO{sub x} commercial burner has also been verified in a laboratory test station that simulates the operation of a water heater. It was determined that the LSB can generate NO{sub x} emissions < 10 ppm (at 3% O{sub 2}) without significant effect on the thermal efficiency of the conventional system. The study has demonstrated that the lean premixed LSB has commercial potential for use as a simple economical and versatile burner for many low emission gas appliances.
Date: July 7, 1999
Creator: Yegian, D. T. & Cheng, R. K.
Object Type: Article
System: The UNT Digital Library
Water Flow Vibration Effect on the NLC RF Structure-Girder System (open access)

Water Flow Vibration Effect on the NLC RF Structure-Girder System

As part of the vibration budget study for the NLC Main Linac components, the vibration sources in the NLC modules (Girder) are under investigation. The activity is focused on the effect of cooling water flow on the structures (FXB type) stability, the transmission of vibrations to the adjacent components, and the effect of different materials of construction used for the supports. Experimental data and ANSYS simulations have been compared. This paper reports on the ongoing work.
Date: July 7, 2004
Creator: al., Cristian Boffo et
Object Type: Article
System: The UNT Digital Library
Data acquisition and analysis for the Fermilab Collider RunII (open access)

Data acquisition and analysis for the Fermilab Collider RunII

Operating and improving the understanding of the Fermilab Accelerator Complex for the colliding beam experiments requires advanced software methods and tools. The Shot Data Acquisition and Analysis (SDA) has been developed to fulfill this need. The SDA takes a standard set of critical data at relevant stages during the complex series of beam manipulations leading to {radical}(s) {approx} 2 TeV collisions. Data is stored in a relational database, and is served to programs and users via Web based tools. Summary tables are systematically generated during and after a store. Written entirely in Java, SDA supports both interactive tools and application interfaces used for in-depth analysis. In this talk, we present the architecture and described some of our analysis tools. We also present some results on the recent Tevatron performance as illustrations of the capabilities of SDA.
Date: July 7, 2004
Creator: al., Paul L. G. Lebrun et
Object Type: Article
System: The UNT Digital Library
Cosmological moduli problem in a supersymmetric model with direct gauge mediation (open access)

Cosmological moduli problem in a supersymmetric model with direct gauge mediation

Recently, an interesting class of the direct gauge mediation supersymmetry (SUSY) breaking models are proposed, in which the minimum of the potential of the SUSY breaking field is determined by the inverted hierarchy mechanism. We consider their cosmological implications. In this class of models, SUSY breaking field has a very flat potential, which may have a cosmological importance. Assuming the initial amplitude of the SUSY breaking field to be of the order of the Planck scale, it can be a source of a large entropy production. A special attention is paid to the cosmological moduli problem, and we will see the cosmological mass density of the moduli field can be significantly reduced.
Date: July 7, 1998
Creator: Moroi, Takeo
Object Type: Article
System: The UNT Digital Library
Tanks 3F and 2F Saltcake Core and Supernate Sample Analysis (open access)

Tanks 3F and 2F Saltcake Core and Supernate Sample Analysis

In support of Low-Curie Salt (LCS) process validation at the Savannah River Site (SRS), Liquid Waste Disposition (LWD) has undertaken a program of tank waste characterization, including salt sampling. As part of this initiative, they sampled the surface of the saltcake in Tank 3F and Tank 2F using approximately 12-inch long sample tubes. A series of three saltcake samples were taken of the upper crust in Tank 3F and a single saltcake sample was taken from the bottom of a liquid-filled well in Tank 2F. In addition to analysis of the solid saltcake samples, the liquid contained in the Tank 3F samples and a separate supernate sample from Tank 2F were studied. The primary objective of the characterization is to gather information that will be useful to the selection and processing of the next waste tanks. Most important is the determination of the 137Cs concentration and liquid retention properties of Tank 3F and Tank 2F saltcake to enable projection of drained, dissolved salt composition. Additional information will aid in refining the waste characterization system (WCS) and could assist the eventual salt treatment or processing.
Date: July 7, 2004
Creator: Martino, Christopher J.; Nichols, R. L.; McCabe, D. J.; Millings, M. R. & Denham, M. E.
Object Type: Report
System: The UNT Digital Library
Modeling of beam loss in Tevatron and backgrounds in the BTeV detector (open access)

Modeling of beam loss in Tevatron and backgrounds in the BTeV detector

Detailed STRUCT simulations are performed on beam loss rates in the vicinity of the BTeV detector in the Tevatron CO interaction region due to beam-gas nuclear elastic interactions and out-scattering from the collimation system. Corresponding showers induced in the machine components and background rates in BTeV are modeled with the MARS14 code. It is shown that the combination of a steel collimator and concrete shielding wall located in front of the detector can reduce the accelerator-related background rates in the detector by an order of magnitude.
Date: July 7, 2004
Creator: Drozhdin, Alexandr I. & Mokhov, Nikolai V.
Object Type: Article
System: The UNT Digital Library
Retrospective application of online catalog author authority control: A pilot project (open access)

Retrospective application of online catalog author authority control: A pilot project

A total of 56 author authority records were created or revised in the Fermilab online catalog. An example of a correct author authority record is given. Since the author authority records used 400 fields and thus pipe all the variant names to the one record, any additions of records with any of these variants will be handled by the online catalog. It is likely that we have included most of the common variants of key Fermilab authors' names, so the database should stay cleaner and more functional for years to come. This project was a success. Therefore an immediate future plan is to implement additional author authority records for the remainder of the authors in the database. Afterwards, authority maintenance should be built in to Library work processes as an ongoing task.
Date: July 7, 1999
Creator: Berkhout, Therese A. & Tompson, Sara R.
Object Type: Report
System: The UNT Digital Library
Performance evaluation of cleanroom environmental systems (open access)

Performance evaluation of cleanroom environmental systems

This paper presents in-situ measurement results for energy and environmental performance of thirteen cleanroom systems located in the USA, including key metrics for evaluating cleanroom air system performance and overall electric power intensity. Comparisons with the IEST Recommended Practice (IEST-RP-CC012.1) are made to examine the performance of cleanroom air systems. Based upon the results, the paper discusses likely opportunities for improving cleanroom energy efficiency while maintaining effective contamination control. The paper concludes that there are wide variations in energy performance of cleanroom environmental systems, and that performance benchmarking can serve as a vehicle to identify energy efficient cleanroom design practices and to highlight important issues in cleanroom operation and maintenance.
Date: July 7, 2003
Creator: Xu, Tengfang
Object Type: Article
System: The UNT Digital Library
Experimental Investigation of Radio-Turbulence Induced Diffusion -- Final Report (open access)

Experimental Investigation of Radio-Turbulence Induced Diffusion -- Final Report

The outcome of this research project suggests that the transport of radon in water is significantly greater than that predicted solely by molecular diffusion. The original study was related to the long term storage of {sup 226}Ra-bearing sand at the DOE Fernald site and determining whether a barrier of water covering the sand would be effective in reducing the emanation of {sup 222}Rn from the sand. Initial observations before this study found the transport of radon in water to be greater than that predicted solely by molecular diffusion. Fick's law on diffusion was used to model the transport of radon in water including the impact associated with radioactive decay. Initial measurements suggested that the deposition of energy in water associated with the radioactive decay process influences diffusion and enhances transport of radon. A multi-region, one-dimensional, steady-state transport model was used to analyze the movement of radon through a sequential column of air, water and air. An effective diffusion coefficient was determined by varying the thickness of the water column and measuring the time for transport of {sup 222}Rn through of the water barrier. A one-region, one-dimensional transient diffusion equation was developed to investigate the build up of radon at the …
Date: July 7, 2005
Creator: Spitz, H. B. & Usman, S.
Object Type: Report
System: The UNT Digital Library
Design of the Main Injector extraction beamlines (open access)

Design of the Main Injector extraction beamlines

The Main Injector (MI) supports the Tevatron Fixed Tar- get and Proton-Antiproton Collider modes of operation as well as providing 120 GeV/c resonantly extracted beam for the Main Injector Fixed Target Program. A set of beam transport lines, called Al and Pl, from the Main Injector converge on the injection point of the Tevatron, with the Al being used to transport 150 GeV/c antipro- tons (pbars) to the Tevatron. Pl is used to transport 150 GeV/c protons to the Tevatron, 120 GeV/c protons to the pbar target, and eventually 120 GeV/c resonantly ex- tracted protons to the existing Fixed Target areas. In ad- dition, the Pl line will be used to transport 8.9 GeV/c pbars from the Source back to the MI and recycled 150 GeV/c pbars at the end of Collider stores. In order to ac- complish the second and third function, the Pl beamline is continued beyond the Tevatron injection point in a sec- tion of the decommissioned Main Ring, called the P2 beamline. This transports the protons to a magnetic switch used to select either the modified transport line, used for targeting protons for pbar production, or the transport line which connects to the existing Fixed Target …
Date: July 7, 1999
Creator: Johnson, David E.
Object Type: Article
System: The UNT Digital Library
Cross-calibrating Spatial Positions of Light-viewing Diagnostics using Plasma Edge Sweeps in DIII-D (open access)

Cross-calibrating Spatial Positions of Light-viewing Diagnostics using Plasma Edge Sweeps in DIII-D

An experimental technique is presented that permits diagnostics viewing light from the plasma edge to be spatially calibrated relative to one another. By sweeping the plasma edge, each chord of each diagnostic sweeps out a portion of the light emission profile. A nonlinear least-squares fit to such data provides superior cross-calibration of diagnostics located at different toroidal locations compared with simple surveying. Another advantage of the technique is that it can be used to monitor the position of viewing chords during an experimental campaign to ensure that alignment does not change over time. Moreover, should such a change occur, the data can still be cross-calibrated and its usefulness retained.
Date: July 7, 2003
Creator: Solomon, W.M.; Burrell, K.H.; Gohil, P.; Groebner, R. & Kaplan, D.
Object Type: Report
System: The UNT Digital Library
Determining size-specific emission factors for environmental tobacco smoke particles (open access)

Determining size-specific emission factors for environmental tobacco smoke particles

Because size is a major controlling factor for indoor airborne particle behavior, human particle exposure assessments will benefit from improved knowledge of size-specific particle emissions. We report a method of inferring size-specific mass emission factors for indoor sources that makes use of an indoor aerosol dynamics model, measured particle concentration time series data, and an optimization routine. This approach provides--in addition to estimates of the emissions size distribution and integrated emission factors--estimates of deposition rate, an enhanced understanding of particle dynamics, and information about model performance. We applied the method to size-specific environmental tobacco smoke (ETS) particle concentrations measured every minute with an 8-channel optical particle counter (PMS-LASAIR; 0.1-2+ micrometer diameters) and every 10 or 30 min with a 34-channel differential mobility particle sizer (TSI-DMPS; 0.01-1+ micrometer diameters) after a single cigarette or cigar was machine-smoked inside a low air-exchange-rate 20 m{sup 3} chamber. The aerosol dynamics model provided good fits to observed concentrations when using optimized values of mass emission rate and deposition rate for each particle size range as input. Small discrepancies observed in the first 1-2 hours after smoking are likely due to the effect of particle evaporation, a process neglected by the model. Size-specific ETS particle …
Date: July 7, 2002
Creator: Klepeis, Neil E.; Apte, Michael G.; Gundel, Lara A.; Sextro, Richard G. & Nazaroff, William W.
Object Type: Article
System: The UNT Digital Library
Numerical Study of Instabilities Driven by Energetic Neutral Beam Ions in NSTX (open access)

Numerical Study of Instabilities Driven by Energetic Neutral Beam Ions in NSTX

Recent experimental observations from NSTX [National Spherical Torus Experiment] suggest that many modes in a subcyclotron frequency range are excited during neutral-beam injection (NBI). These modes have been identified as Compressional Alfven Eigenmodes (CAEs) and Global Alfven Eigenmodes (GAEs), which are driven unstable through the Doppler-shifted cyclotron resonance with the beam ions. The injection velocities of the NBI ions in NSTX are large compared to Alfven velocity, V(sub)0 > 3V(sub)A, and a strong anisotropy in the fast-ion pitch-angle distribution provides the energy source for the instabilities. Recent interest in the excitation of Alfven Eigenmodes in the frequency range omega less than or approximately equal to omega(sub)ci, where omega(sub)ci is the ion cyclotron frequency, is related to the possibility that these modes can provide a mechanism for direct energy transfer from super-Alfvenic beam ions to thermal ions. Numerical simulations are required in order to find a self-consistent mode structure, and to include the effects of finite-Larmor radius (FLR), the nonlinear effects, and the thermal plasma kinetic effects.
Date: July 7, 2003
Creator: Belova, E. V.; Gorelenkov, N. N.; Cheng, C. Z. & Fredrickson, E. D.
Object Type: Report
System: The UNT Digital Library
Investigation of Plutonium and Uranium Precipitation Behavior with Gadolinium as a Neutron Poison (open access)

Investigation of Plutonium and Uranium Precipitation Behavior with Gadolinium as a Neutron Poison

The neutralization of solutions containing significant quantities of fissile material at the Department of Energy's Savannah River Site and the subsequent transfer of the slurry to the High Level Waste (HLW) system is accomplished with the addition of a neutron poison to ensure nuclear safety. Gd, depleted U, Fe, and Mn have been used as poisons in the caustic precipitation of process solutions prior to discarding to HLW. However, the use of Gd is preferred since only small amounts of Gd are necessary for effective criticality control, smaller volumes of metal hydroxides are produced, and the volume of HLW glass resulting from this process is minimized.
Date: July 7, 2003
Creator: Visser, A.E.
Object Type: Report
System: The UNT Digital Library