Defense In-Depth Accident Analysis Evaluation of Tritium Facility Bldgs. 232-H, 233-H, and 234-H (open access)

Defense In-Depth Accident Analysis Evaluation of Tritium Facility Bldgs. 232-H, 233-H, and 234-H

'The primary purpose of this report is to document a Defense-in-Depth (DID) accident analysis evaluation for Department of Energy (DOE) Savannah River Site (SRS) Tritium Facility Buildings 232-H, 233-H, and 234-H. The purpose of a DID evaluation is to provide a more realistic view of facility radiological risks to the offsite public than the bounding deterministic analysis documented in the Safety Analysis Report, which credits only Safety Class items in the offsite dose evaluation.'
Date: May 10, 1999
Creator: Blanchard, A.
Object Type: Report
System: The UNT Digital Library
Annual Report 1998. Chemical Structure and Dynamics (open access)

Annual Report 1998. Chemical Structure and Dynamics

No abstract currently available for this report as the present time.
Date: May 10, 1999
Creator: Colson, Steven D. & McDowell, Robin S.
Object Type: Report
System: The UNT Digital Library
Characterization of the Low Level Waste Reference Glass (LRM) (open access)

Characterization of the Low Level Waste Reference Glass (LRM)

'The Savannah River Technology Center (SRTC) has participated in a round robin testing program which was conducted under the auspices of the Department of Energy''s (DOE) Tanks Focus Area (TFA) for Immobilization.'
Date: May 10, 1999
Creator: Peeler, D.
Object Type: Report
System: The UNT Digital Library
An Evaluation of Liquidus Temperature as a Function of Waste Loading for a Tank 42 "Sludge Only"/Frit 200 Flowsheet (open access)

An Evaluation of Liquidus Temperature as a Function of Waste Loading for a Tank 42 "Sludge Only"/Frit 200 Flowsheet

'The waste glass produced in the SRS Defense Waste Processing Faiclity (DWPF) process must comply with Waste Acceptance Product Specifications (WAPS) and process control requirements by demonstrating, to a high degree of confidence, that melter feed will produce glass satisfying all quality and processing requirements.'
Date: May 10, 1999
Creator: Peeler, D.
Object Type: Report
System: The UNT Digital Library
Glass Waste Forms for Oak Ridge Tank Wastes: Fiscal Year 1998 Report for Task Plan SR-16WT-31, Task B (open access)

Glass Waste Forms for Oak Ridge Tank Wastes: Fiscal Year 1998 Report for Task Plan SR-16WT-31, Task B

Using ORNL information on the characterization of the tank waste sludges, SRTC performed extensive bench-scale vitrification studies using simulants. Several glass systems were tested to ensure the optimum glass composition (based on the glass liquidus temperature, viscosity and durability) is determined. This optimum composition will balance waste loading, melt temperature, waste form performance and disposal requirements. By optimizing the glass composition, a cost savings can be realized during vitrification of the waste. The preferred glass formulation was selected from the bench-scale studies and recommended to ORNL for further testing with samples of actual OR waste tank sludges.
Date: May 10, 1999
Creator: Andrews, M.K.
Object Type: Report
System: The UNT Digital Library
Defense In-Depth Accident Analysis Evaluation of Tritium Facility Bldgs. 232-H, 233-H, and 234-H (open access)

Defense In-Depth Accident Analysis Evaluation of Tritium Facility Bldgs. 232-H, 233-H, and 234-H

'The primary purpose of this report is to document a Defense-in-Depth (DID) accident analysis evaluation for Department of Energy (DOE) Savannah River Site (SRS) Tritium Facility Buildings 232-H, 233-H, and 234-H. The purpose of a DID evaluation is to provide a more realistic view of facility radiological risks to the offsite public than the bounding deterministic analysis documented in the Safety Analysis Report, which credits only Safety Class items in the offsite dose evaluation.'
Date: May 10, 1999
Creator: Blanchard, A.
Object Type: Report
System: The UNT Digital Library
Toxic Substances From Coal Combustion (open access)

Toxic Substances From Coal Combustion

The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environ-mental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 January 1999 to 31 March 1999. During this period, a full Program Review Meeting was held at the University of Arizona. At this meeting, the …
Date: May 10, 1999
Creator: Kolker, A.; Sarofim, A. F.; Palmer, C. A.; Huggins, F. E.; Huffman, G. P.; Lighty, J. et al.
Object Type: Report
System: The UNT Digital Library
The Savannah River Site's Groundwater Monitoring Program Third Quarter 1998 (July through September 1998) (open access)

The Savannah River Site's Groundwater Monitoring Program Third Quarter 1998 (July through September 1998)

This report summarizes the Groundwater Monitoring Program conducted by SRS during third quarter 1998. It includes the analytical data, field data, data review, quality control, and other documentation for this program; provides a record of the program's activities; and serves as an official record of the analytical results.
Date: May 10, 1999
Creator: Hutchison, J.B.
Object Type: Report
System: The UNT Digital Library
Radiant heat transfer from storage casks to the environment (open access)

Radiant heat transfer from storage casks to the environment

A spent fuel storage cask must efficiently transfer the heat released by the fuel assemblies through the cask walls to the environment. This heat must be transferred through passive means, limiting the energy transfer mechanisms from the cask to natural convection and radiation heat transfer.. Natural convection is essentially independent of the characteristics of the array of casks, provided there is space between casks to permit a convection loop. Radiation heat transfer, however, depends on the geometric arrangement of the array of casks because the peripheral casks will shadow the interior casks and restrict radiant heat transfer from all casks to the environment. The shadowing of one cask by its neighbors is determined by a view factor that represents the fraction of radiant energy that leaves the surface of a cask and reaches the environment. This paper addresses the evaluation of the view factor between a centrally located spent fuel storage cask and the environment. By combining analytic expressions for the view factor of (1) infinitely long cylinders and (2) finite cylinders with a length-to-diameter ratio of 2 to represent spent fuel storage casks, the view factor can be evaluated for any practical array of spent fuel storage casks.
Date: May 10, 1999
Creator: Carlson, R. W.; Hovingh, J. & Thomas, G. R.
Object Type: Article
System: The UNT Digital Library
SOME PHYSICAL AND ENGINEERING ASPECTS OF HIGH CURRENT EBIS. (open access)

SOME PHYSICAL AND ENGINEERING ASPECTS OF HIGH CURRENT EBIS.

Some applications of an Electron Beam Ion Source (EBIS) require intensities of highly charged ions significantly greater than those which have been achieved in present EBIS sources. For example, the ion source for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) must be capable of generating 3x10{sup 9} ions of Au{sup 35+} or 2 x 10{sup 9} ions of U{sup 45+} per pulse [1]. In this case, if the fraction of ions of interest is 20% of the total ion space charge, the total extracted charge is {approx}{approx} 5 x 10{sup 11}. It is also desirable to extract these ions in a 10 ps pulse to allow single turn injection into the first synchrotron. Requirements for an EBIS which could meet the needs of the LHC at CERN are similar ({approx} 1.5 x 10{sup 9} ions of Pb{sup 54+} in 5.5 {micro}s). This charge yield is about an order of magnitude greater than that achieved in existing EBIS sources, and is what is meant here by ''high current''. This also implies, then, an EBIS with a high electron beam current. The scope of problems in a high current EBIS is broad, and includes generating a sufficient total …
Date: May 10, 1999
Creator: Pikin, A.
Object Type: Book
System: The UNT Digital Library
Prototype 350 MHz niobium spoke-loaded cavities. (open access)

Prototype 350 MHz niobium spoke-loaded cavities.

This paper reports the development of 350 MHz superconducting cavities of a spoke-loaded geometry, intended for the velocity range 0.2 < v/c < 0.6. Two prototype single-cell cavities have been designed, one optimized for velocity v/c = 0.4, and the other for v/c = 0.29. Construction of the prototype niobium cavities is nearly complete. Details of the design and construction are discussed, along with the results of cold tests.
Date: May 10, 1999
Creator: Delayen, J. R.; Kedzie, M.; Mammosser, J.; Piller, C. & Shepard, K. W.
Object Type: Article
System: The UNT Digital Library
Development of Back-Illuminated, Fully-Depleted CCD Image Sensors for Use in Optical and Near-IR Astronomy (open access)

Development of Back-Illuminated, Fully-Depleted CCD Image Sensors for Use in Optical and Near-IR Astronomy

Charge-coupled devices (CCD's) of novel design have been fabricated at Lawrence Berkeley National Laboratory (LBNL), and the first large-format science-grade chips for astronomical imaging are now being characterized at Lick Observatory. They are made on 300-μm thick n-type high-resistivity (~10,000 Ω-cm) silicon wafers, using a technology developed at LBNL to fabricate low-leakage silicon microstrip detectors for high-energy physics. A bias voltage applied via a transparent contact on the back side fully depletes the substrate, making the entire volume photosensitive and ensuring that charge reaches the potential wells with minimal lateral diffusion. The development of a thin, transparent back side contact compatible with fully depleted operation permits blue response comparable to that obtained with thinned CCD's. Since he entire region is active, high quantum efficiency is maintained to nearly λ = 1000 nm, above which the silicon bandgap effectively truncates photoproduction. Early characterization results indicate a charge transfer efficiency > 0.999995, readout noise 4 e's at -132°C, full well capacity > 300,000 e's, and quantum efficiency > 85% at λ = 900 nm.
Date: May 10, 1999
Creator: Groom, D. E.; Holland, S. E.; Levi, M. E.; Palaio, N. P.; Perlmutter,S.; Stover, R. J. et al.
Object Type: Article
System: The UNT Digital Library
SECONDARY LOW-LEVEL WASTE GENERATION RATE ANALYSIS (open access)

SECONDARY LOW-LEVEL WASTE GENERATION RATE ANALYSIS

The objective of this design analysis is -to update the assessment of estimated annual secondary low-level waste (LLW) generation rates resulting from the repackaging of spent nuclear fuel (SNF) and high-level waste (HLW) for disposal at the Monitored Geologic Repository (MGR). This analysis supports the preparation of documentation necessary for license application (LA) for the MGR. For the purposes of this analysis, secondary LLW is defined, in brief terms, as LLW generated as a direct result of processing SNF/HLW through the receiving and repackaging operations. The current Waste Handling Building (WHB) design is based on the predominant movement of fuel assemblies through the wet handling lines within the WHB. Dry handling lines are also included in the current WHB design to accommodate canistered waste (i.e., SNF and/or HLW packages). Major input changes to this analysis in comparison to previous analyses include: (1) changes in the SNF/HLW arrival schedules; (2) changes to the WHB and the Waste Treatment Building (WTB) dimensions; and (3) changes in operational staff sizes within the WHB and WTB. The rates generated in this analysis can be utilized to define necessary waste processes, waste flow rates, and equipment sizes for the processing of secondary LLW for proper …
Date: May 10, 1999
Creator: LaRue, D.
Object Type: Report
System: The UNT Digital Library
Annual Report 1998: Chemical Structure and Dynamics (open access)

Annual Report 1998: Chemical Structure and Dynamics

The Chemical Structure and Dynamics (CS&D) program is a major component of the William R. Wiley Environmental Molecular Sciences Labo- ratory (EMSL), developed by Pacific Northwest National Laboratory (PNNL) to provide a state-of- the-art collaborative facility for studies of chemical structure and dynamics. We respond to the need for a fundamental, molecular-level understanding of chemistry at a wide variety of environmentally important interfaces by (1) extending the experimental characterization and theoretical description of chemical reactions to encompass the effects of condensed media and interfaces; (2) developing a multidisciplinary capability for describing interracial chemical processes within which the new knowledge generated can be brought to bear on complex phenomena in envi- ronmental chemistry and in nuclear waste proc- essing and storage; and (3) developing state-of- the-art analytical methods for characterizing com- plex materials of the types found in stored wastes and contaminated soils, and for detecting and monitoring trace atmospheric species. Our program aims at achieving a quantitative understanding of chemical reactions at interfaces and, more generally, in condensed media, compa- rable to that currently available for gas-phase reactions. This understanding will form the basis for the development of a priori theories for pre- dicting macroscopic chemical behavior in con- densed …
Date: May 10, 1999
Creator: Colson, Steven D. & McDowell, Robin S.
Object Type: Report
System: The UNT Digital Library
In situ vibrational spectroscopic investigation of C{sub 4} hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts (open access)

In situ vibrational spectroscopic investigation of C{sub 4} hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.
Date: May 10, 1999
Creator: Xue, Z.Y.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Inductively coupled plasma mass spectrometry for stable isotope metabolic tracer studies of living systems (open access)

Inductively coupled plasma mass spectrometry for stable isotope metabolic tracer studies of living systems

This dissertation focuses on the development of methods for stable isotope metabolic tracer studies in living systems using inductively coupled plasma single and dual quadrupole mass spectrometers. Sub-nanogram per gram levels of molybdenum (Mo) from human blood plasma are isolated by the use of anion exchange alumina microcolumns. Million-fold more concentrated spectral and matrix interferences such as sodium, chloride, sulfate, phosphate, etc. in the blood constituents are removed from the analyte. The recovery of Mo from the alumina column is 82 {+-} 5% (n = 5). Isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) is utilized for the quantitative ultra-trace concentration determination of Mo in bovine and human blood samples. The average Mo concentration in reference bovine serum determined by this method is 10.2 {+-} 0.4 ng/g, while the certified value is 11.5 {+-} 1.1 ng/g (95% confidence interval). The Mo concentration of one pool of human blood plasma from two healthy male donors is 0.5 {+-} 0.1 ng/g. The inductively coupled plasma twin quadrupole mass spectrometer (ICP-TQMS) is used to measure the carbon isotope ratio from non-volatile organic compounds and bio-organic molecules to assess the ability as an alternative analytical method to gas chromatography combustion isotope ratio mass spectrometry …
Date: May 10, 1999
Creator: Luong, E.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Press and dryer roll surfaces and web transfer systems for ultra high paper machine speeds. Quarterly report {number_sign}1 (open access)

Press and dryer roll surfaces and web transfer systems for ultra high paper machine speeds. Quarterly report {number_sign}1

The objective of the project is to provide fundamental knowledge and diagnostic tools needed to design new technologies that will allow ultra high speed web transfer from press rolls to dryer cylinders. A brief summary is given for the progress made on each of the following research tasks: Task 1--identify composition of contaminants and topology of press and dryer roll surfaces at commercial mills; Task 2--develop facilities to simulate contaminant deposition process under controlled experimental conditions; Task 3--develop facilities to simulate web transfer from contaminant surfaces and measure work of adhesion; Task 4--develop models to predict contaminant deposition and work of adhesion; Task 5--develop and verify model to predict web transfer at ultra high paper machine speeds; and Task 6--develop and demonstrate new roll surface conditioning technologies.
Date: May 10, 1999
Creator: Orloff, D. I.
Object Type: Report
System: The UNT Digital Library
Atom transfer and rearrangement reactions catalyzed by methyltrioxorhenium, MTO (open access)

Atom transfer and rearrangement reactions catalyzed by methyltrioxorhenium, MTO

Methyltrioxorhenium (MTO) catalyzes the desulfurization of thiiranes by triphenylphosphine. Enormous enhancement in rate is observed when the catalyst is pretreated with hydrogen sulfide prior to the reaction. Using 2-mercaptomethylthiophenol as a ligand, the author synthesized several model complexes to study the mechanism of this reaction. With suitable model systems, they were able to show that the active catalyst is a Re(V) species. The reactions are highly stereospecific and very tolerant to functional groups. As part of the studies, he synthesized and crystallographically characterized the first examples of neutral terminal and bridging Re(V)sulfidocomplexes. Some of these complexes undergo fast oxygen atom transfer reactions with organic and inorganic oxidants. Studies on these model complexes led them to the discovery that MTO catalyzes the selective oxidation of thiols to disulfides. This report contains the Introduction; ``Chapter 6: Isomerization of Propargylic Alcohols to Enones and Enals Catalyzed by Methylrhenium Trioxide``; and Conclusions.
Date: May 10, 1999
Creator: Jacob, J.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The interplay of long-range magnetic order and single-ion anisotropy in rare earth nickel germanides (open access)

The interplay of long-range magnetic order and single-ion anisotropy in rare earth nickel germanides

This dissertation is concerned with the interplay of long-range order and anisotropy in the tetragonal RNi{sub 2}Ge{sub 2} (R = rare earth) family of compounds. Microscopic magnetic structures were studied using both neutron and x-ray resonant exchange scattering (XRES) techniques. The magnetic structures of Tb, Dy, Eu and Gd members have been determined using high-quality single-crystal samples. This work has correlated a strong Fermi surface nesting to the magnetic ordering in the RNi{sub 2}Ge{sub 2} compounds. Generalized susceptibility, {chi}{sub 0}(q), calculations found nesting to be responsible for both incommensurate ordering wave vector in GdNi{sub 2}Ge{sub 2}, and the commensurate structure in EuNi{sub 2}Ge{sub 2}. A continuous transition from incommensurate to commensurate magnetic structures via band filling is predicted. The surprisingly higher T{sub N} in EuNi{sub 2}Ge{sub 2} than that in GdNi{sub 2}Ge{sub 2} is also explained. Next, all the metamagnetic phases in TbNi{sub 2}Ge{sub 2} with an applied field along the c axis have been characterized with neutron diffraction measurements. A mixed phase model for the first metamagnetic structure consisting of fully-saturated as well as reduced-moment Tb ions is presented. The moment reduction may be due to moment instability which is possible if the exchange is comparable to the low-lying …
Date: May 10, 1999
Creator: Islam, Z.
Object Type: Report
System: The UNT Digital Library
Drain Holes for Criticality Safety Control Guidance for the Analyst (open access)

Drain Holes for Criticality Safety Control Guidance for the Analyst

Drain and overflow holes are integral to the nuclear criticality safety basis of many processes and provide different functions inachieving their safety goaL Inmost cases at the Oak RidgeY-12 Plant, unverified engineering judgment has been previously used to conclude that the holes were adequate to accomplish their mission. Such judgment may adequately serve some configurations but is inadequate in other applications. It is important to understand and document the exact function of every drain for both normal and upset process conditions. After this is accomplished, the holes must be demonstrated to be capable of penlorming their intended safety fi,mction. This paper gives examples of different types of drains used for criticality safety, gives examples of how to ensure they will work as intended, and gives guidance to the analyst who relies on such holes to prevent criticality accidents.
Date: May 10, 1999
Creator: LeTellier, M. S. & Smallwood, D. J.
Object Type: Article
System: The UNT Digital Library
PNNL Review of Proposed Relevant Radionuclide List (open access)

PNNL Review of Proposed Relevant Radionuclide List

A list of fission products and activation products has been proposed for possible adoption as an official table of relevant isotopes for CTBT use. It is our understanding that the purpose of this list is to discriminate Level 4 spectra from Level 5 spectra in the decision logic diagram. The current understanding is that a single short-lived, relevant isotope that is atypical for a station would cause a spectrum to be marked as Level 4. A second relevant isotope would cause a spectrum to be marked as Level 5, which would perhaps require a sample to undergo additional laboratory conflation measurements. The list consists of a very comprehensive set of fission products and activation products. We have examined the list for accuracy and have also flagged potential problems with members of the list. in our opinion, several of these isotopes have serious problems and many have no practical chance of ever being the first or second detected isotopes. We are not arguing whether or not these isotopes might be seen in a large atmospheric test. On the other hand, there may be no harm associated with having a long list. The issue of activation products is different. Some activation products …
Date: May 10, 1999
Creator: Miley, H. S. & Arthur, R. J.
Object Type: Report
System: The UNT Digital Library
Crystalline-Silicon Solar Cells for the 21st Century (open access)

Crystalline-Silicon Solar Cells for the 21st Century

The worldwide market share for crystalline-silicon solar cells has increased steadily in the last 10 years. In 1998, about 87% of the photovoltaic modules shipped worldwide are based on crystalline silicon. This dominance will likely continue into at least the first few years of the 21st century. The long-term growth of crystalline-silicon solar cells will depend on the development of low-cost polysilicon feedstock, silicon films, and advanced cell and module manufacturing processes.
Date: May 10, 1999
Creator: Tsuo, Y. S.; Wang, T. H. & Ciszek, T. F.
Object Type: Article
System: The UNT Digital Library
Developing a CD-CBM Anticipatory Approach for Cavitation - Defining a Model Descriptor Consistent Between Processes (open access)

Developing a CD-CBM Anticipatory Approach for Cavitation - Defining a Model Descriptor Consistent Between Processes

A major problem with cavitation in pumps and other hydraulic devices is that there is no effective method for detecting or predicting its inception. The traditional approach is to declare the pump in cavitation when the total head pressure drops by some arbitrary value (typically 3o/0) in response to a reduction in pump inlet pressure. However, the pump is already cavitating at this point. A method is needed in which cavitation events are captured as they occur and characterized by their process dynamics. The object of this research was to identify specific features of cavitation that could be used as a model-based descriptor in a context-dependent condition-based maintenance (CD-CBM) anticipatory prognostic and health assessment model. This descriptor was based on the physics of the phenomena, capturing the salient features of the process dynamics. An important element of this concept is the development and formulation of the extended process feature vector @) or model vector. Thk model-based descriptor encodes the specific information that describes the phenomena and its dynamics and is formulated as a data structure consisting of several elements. The first is a descriptive model abstracting the phenomena. The second is the parameter list associated with the functional model. The …
Date: May 10, 1999
Creator: Allgood, G. O.; Dress, W. B. & Kercel, S. W.
Object Type: Article
System: The UNT Digital Library
Use of Reciprocal Lattice Layer Spacing in Electron Backscatter Diffraction Pattern Analysis (open access)

Use of Reciprocal Lattice Layer Spacing in Electron Backscatter Diffraction Pattern Analysis

In the scanning electron microscope (SEM), using electron backscattered diffraction (EBSD), it is possible to measure the spacing of the layers in the reciprocal lattice. These values are of great use in confirming the identification of phases. The technique derives the layer spacing from the HOLZ rings which appear in patterns from many materials. The method adapts results from convergent-beam electron diffraction (CBED) in the transmission electron microscope (TEM). For many materials the measured layer spacing compares well with the calculated layer spacing. A noted exception is for higher atomic number materials. In these cases an extrapolation procedure is described that requires layer spacing measurements at a range of accelerating voltages. This procedure is shown to improves the accuracy of the technique significantly. The application of layer spacing measurements in EBSD is shown to be of use for the analysis of two polytypes of SiC.
Date: May 10, 1999
Creator: Michael, J. R. & Eades, J. A.
Object Type: Article
System: The UNT Digital Library