QUESTIONNAIRE ON THE CAPABILITIES OF MEMBER STATES REGARDING THE ANALYSIS OF BIOMEDICAL SAMPLES (open access)

QUESTIONNAIRE ON THE CAPABILITIES OF MEMBER STATES REGARDING THE ANALYSIS OF BIOMEDICAL SAMPLES

None
Date: March 27, 2006
Creator: Alcaraz, A. & Gregg, H.
Object Type: Report
System: The UNT Digital Library
Seismic imaging of reservoir flow properties: Resolving waterinflux and reservoir permeability (open access)

Seismic imaging of reservoir flow properties: Resolving waterinflux and reservoir permeability

Methods for geophysical model assessment, in particuale thecomputation of model parameter resolution, indicate the value and thelimitations of time-lapse data in estimating reservoir flow properties. Atrajectory-based method for computing sensitivities provides an effectivemeans to compute model parameter resolutions. We examine the commonsituation in which water encroaches into a resrvoir from below, as due tothe upward movement of an oil-water contact. Using straight-forwardtechniques we find that, by inclusing reflections off the top and bottomof a reservoir tens of meters thick, we can infer reservoir permeabilitybased upon time-lapse data. We find that, for the caseof water influxfrom below, using multiple time-lapse 'snapshots' does not necessarilyimprove the resolution of reservoir permeability. An application totime-lapse data from the Norne field illustrates that we can resolve thepermeability near a producing well using reflections from threeinterfaces associated with the reservoir.
Date: November 27, 2006
Creator: Vasco, D.W. & Keers, Henk
Object Type: Article
System: The UNT Digital Library
Do grain boundaries in nanophase metals slide? (open access)

Do grain boundaries in nanophase metals slide?

Nanophase metallic materials show a maximum in strength as grain size decreases to the nano scale, indicating a break down of the Hall-Petch relation. Grain boundary sliding, as a possible accommodation mechanisms, is often the picture that explain computer simulations results and real experiments. In a recent paper, Bringa et al. Science 309, 1838 (2005), we report on the observation of an ultra-hard behavior in nanophase Cu under shock loading, explained in terms of a reduction of grain boundary sliding under the influence of the shock pressure. In this work we perform a detailed study of the effects of hydrostatic pressure on nanophase Cu plasticity and find that it can be understood in terms of pressure dependent grain boundary sliding controlled by a Mohr-Coulomb law.
Date: October 27, 2006
Creator: Bringa, E M; Leveugle, E & Caro, A
Object Type: Article
System: The UNT Digital Library
The Heavy-Ion Approximation for Ambipolar Diffusion Calcuations for Weakly Ionized Plasmas (open access)

The Heavy-Ion Approximation for Ambipolar Diffusion Calcuations for Weakly Ionized Plasmas

Ambipolar diffusion redistributes magnetic flux in weakly ionized plasmas and plays a critical role in star formation. Simulations of ambipolar diffusion using explicit MHD codes are prohibitively expensive for the level of ionization observed in molecular clouds ({approx}< 10{sup -6}) since an enormous number of time steps is required to represent the dynamics of the dominant neutral component with a time step determined by the trace ion component. Here we show that ambipolar diffusion calculations can be significantly accelerated by the 'heavy-ion approximation', in which the mass density of the ions is increased and the collisional coupling constant with the neutrals decreased such that the product remains constant. In this approximation, the ambipolar diffusion time and the ambipolar magnetic Reynolds number remain unchanged. We present three tests of the heavy-ion approximation: C-type shocks, the Wardle instability, and the 1D collapse of a magnetized slab. We show that this approximation is quite accurate provided that (1) the square of the Alfven Mach number is small compared to the ambipolar diffusion Reynolds number for dynamical problems, and that (2) the ion mass density is negligible for quasi-static problems; a specific criterion is given for the magnetized slab problem. The first condition can …
Date: July 27, 2006
Creator: Li, P; McKee, C & Klein, R
Object Type: Article
System: The UNT Digital Library
FY05 LDRD Final Report Spectroscopy of Shocked Deuterium (open access)

FY05 LDRD Final Report Spectroscopy of Shocked Deuterium

We summarize the observations of unusual optical properties of shocked liquid deuterium (D{sub 2}) that led to proposing spectroscopic measurements. The apparatus built for the measurements is briefly described, along with some representative results in a test material. Unfortunately, spectroscopic measurements were not performed in shocked D{sub 2} during the course of the project. Some reasons are noted.
Date: March 27, 2006
Creator: Holmes, N. C.
Object Type: Report
System: The UNT Digital Library
Reversible expansion of gallium-stabilized (delta)-plutonium (open access)

Reversible expansion of gallium-stabilized (delta)-plutonium

It is shown that the transient expansion of plutonium-gallium alloys observed both in the lattice parameter as well as in the dimension of a sample held at ambient temperature can be explained by assuming incipient precipitation of Pu{sub 3}Ga. However, this ordered {zeta}-phase is also subject to radiation-induced disordering. As a result, the gallium-stabilized {delta}-phase, being metastable at ambient temperature, is driven towards thermodynamic equilibrium by radiation-enhanced diffusion of gallium and at the same time reverted back to its metastable state by radiation-induced disordering. A steady state is reached in which only a modest fraction of the gallium present is arranged in ordered {zeta}-phase regions.
Date: February 27, 2006
Creator: Wolfer, W G; Oudot, B & Baclet, N
Object Type: Article
System: The UNT Digital Library
Analysis of Order Formation in Block Copolymer Thin Films UsingResonant Soft X-Ray Scattering (open access)

Analysis of Order Formation in Block Copolymer Thin Films UsingResonant Soft X-Ray Scattering

The lateral order of poly(styrene-block-isoprene) copolymer(PS-b-PI) thin films is characterized by the emerging technique ofresonant soft X-ray scattering (RSOXS) at the carbon K edge and comparedto ordering in bulk samples of the same materials measured usingconventional small-angle X-ray scattering. We show resonance using theoryand experiment that the loss of scattering intensity expected with adecrease in sample volume in the case of thin films can be overcome bytuning X-rays to the pi* resonance of PS or PI. Using RSOXS, we study themicrophase ordering of cylinder- and phere-forming PS-b-PI thin films andcompare these results to position space data obtained by atomic forcemicroscopy. Our ability to examine large sample areas (~;9000 mu m2) byRSOXS enables unambiguous identification of the lateral lattice structurein the thin films. In the case of the sphere-forming copolymer thin film,where the spheres are hexagonally arranged, the average sphere-to-spherespacing is between the bulk (body-centered cubic) nearest neighbor andbulk unit cell spacings. In the case of the cylinder-forming copolymerthin film, the cylinder-to-cylinder spacing is within experimental errorof that obtained in the bulk.
Date: November 27, 2006
Creator: Virgili, Justin M.; Tao, Yuefei; Kortright, Jeffrey B.; Balsara,Nitash P. & Segalman, Rachel A.
Object Type: Article
System: The UNT Digital Library
Nuclear Resonance Fluorescence Excitations Near 2 MeV in 235U and 239Pu (open access)

Nuclear Resonance Fluorescence Excitations Near 2 MeV in 235U and 239Pu

A search for nuclear resonance fluorescence excitations in {sup 235}U and {sup 239}Pu within the energy range of 1.0- to 2.5-MeV was performed using a 4-MeV continuous bremsstrahlung source at the High Voltage Research Laboratory at the Massachusetts Institute of Technology. Measurements utilizing high purity Ge detectors at backward angles identified 9 photopeaks in {sup 235}U and 12 photopeaks in {sup 239}Pu in this energy range. These resonances provide unique signatures that allow the materials to be non-intrusively detected in a variety of environments including fuel cells, waste drums, vehicles and containers. The presence and properties of these states may prove useful in understanding the mechanisms for mixing low-lying collective dipole excitations with other states at low excitations in heavy nuclei.
Date: December 27, 2006
Creator: Bertozzi, W.; Caggiano, J. A.; Hensley, W. K.; Johnson, M. S.; Korbly, S. E.; Ledoux, R. J. et al.
Object Type: Article
System: The UNT Digital Library
An Efficient Vector Finite Element Method for Nonlinear Electromagnetic Modeling (open access)

An Efficient Vector Finite Element Method for Nonlinear Electromagnetic Modeling

We have developed a mixed Vector Finite Element Method (VFEM) for Maxwell's equations with a nonlinear polarization term. The method allows for discretization of complicated geometries with arbitrary order representations of the B and E fields. In this paper we will describe the method and a series of optimizations that significantly reduce the computational cost. Additionally, a series of test simulations will be presented to validate the method. Finally, a nonlinear waveguide mode mixing example is presented and discussed.
Date: June 27, 2006
Creator: Fisher, A. C.; White, D. A. & Rodrigue, G. H.
Object Type: Article
System: The UNT Digital Library
A Brief Analysis of Geologic CO2 Storage Potential in South Korea (open access)

A Brief Analysis of Geologic CO2 Storage Potential in South Korea

Paper summarizes the literature about geologic CO2 storage potential in South Korea.
Date: June 27, 2006
Creator: Dooley, James J.
Object Type: Report
System: The UNT Digital Library
Space Nuclear Power Plant Pre-Conceptual Design Report, For Information (open access)

Space Nuclear Power Plant Pre-Conceptual Design Report, For Information

This letter transmits, for information, the Project Prometheus Space Nuclear Power Plant (SNPP) Pre-Conceptual Design Report completed by the Naval Reactors Prime Contractor Team (NRPCT). This report documents the work pertaining to the Reactor Module, which includes integration of the space nuclear reactor with the reactor radiation shield, energy conversion, and instrumentation and control segments. This document also describes integration of the Reactor Module with the Heat Rejection segment, the Power Conditioning and Distribution subsystem (which comprise the SNPP), and the remainder of the Prometheus spaceship.
Date: January 27, 2006
Creator: Levine, B.
Object Type: Report
System: The UNT Digital Library
The Two-loop Anomalous Dimension Matrix for Soft Gluon Exchange (open access)

The Two-loop Anomalous Dimension Matrix for Soft Gluon Exchange

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions. We compute this matrix directly for arbitrary 2 {yields} n massless processes for the first time at two loops. Using color generator notation, we show that it is proportional to the one-loop matrix. This result reproduces all pole terms in dimensional regularization of the explicit calculations of massless 2 {yields} 2 amplitudes in the literature, and it predicts all poles at next-to-leading order in any 2 {yields} n process that has been computed at next-to-leading order. The proportionality of the one- and two-loop matrices makes possible the resummation in closed form of the next-to-next-to-leading logarithms and poles in dimensional regularization for the 2 {yields} n processes.
Date: June 27, 2006
Creator: Aybat, S.Mert; Dixon, Lance J. & Sterman, George
Object Type: Report
System: The UNT Digital Library
A Cone Jet-Finding Algorithm for Heavy-Ion Collisions at LHCEnergies (open access)

A Cone Jet-Finding Algorithm for Heavy-Ion Collisions at LHCEnergies

Standard jet finding techniques used in elementary particle collisions have not been successful in the high track density of heavy-ion collisions. This paper describes a modified cone-type jet finding algorithm developed for the complex environment of heavy-ion collisions. The primary modification to the algorithm is the evaluation and subtraction of the large background energy, arising from uncorrelated soft hadrons, in each collision. A detailed analysis of the background energy and its event-by-event fluctuations has been performed on simulated data, and a method developed to estimate the background energy inside the jet cone from the measured energy outside the cone on an event-by-event basis. The algorithm has been tested using Monte-Carlo simulations of Pb+Pb collisions at {radical}s = 5.5 TeV for the ALICE detector at the LHC. The algorithm can reconstruct jets with a transverse energy of 50 GeV and above with an energy resolution of {approx} 30%.
Date: July 27, 2006
Creator: Blyth, S.-L.; Horner, M.J.; Awes, T.C.; Cormier, T.; Gray, H.M.; Klay, J.L. et al.
Object Type: Article
System: The UNT Digital Library
Observation of e+e- Annihilations into the C=+1 Hadronic Final States \rho^0\rho^0 and \phi\rho^0 (open access)

Observation of e+e- Annihilations into the C=+1 Hadronic Final States \rho^0\rho^0 and \phi\rho^0

The authors report the first observation of e{sup +}e{sup -} annihilations into states of positive C-parity, namely {rho}{sup 0}{rho}{sup 0} and {phi}{rho}{sup 0}. The two states are observed in the {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} and K{sup +}K{sup -} {pi}{sup +}{pi}{sup -} final states, respectively, in a data sample of 225 fb{sup -1} collected by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage rings at energies near {radical}s = 10.58 GeV. The distributions of cos {theta}*, where {theta}* is the center-of-mass polar angle of the {phi} meson or the forward {rho}{sup 0} meson, suggest production by two-virtual-photon annihilation. They measure cross sections within the range |cos {theta}*| < 0.8 of {sigma}(e{sup +}e{sup -} {yields} {rho}{sup 0} {rho}{sup 0}) = 20.7 {+-} 0.7(stat) {+-} 2.7(syst) fb and {sigma}(e{sup +}e{sup -} {yields} {phi}{rho}{sup 0}) = 5.7 {+-} 0.5(stat) {+-} 0.8(syst) fb.
Date: June 27, 2006
Creator: Aubert, B.
Object Type: Report
System: The UNT Digital Library
Conducting Polymer-Inorganic Nanoparticle (CPIN) Nanoarrays for Battery Applications - Final Technical Report (open access)

Conducting Polymer-Inorganic Nanoparticle (CPIN) Nanoarrays for Battery Applications - Final Technical Report

Our objective was to develop new, self-assembling conducting polymer-inorganic nanoparticle nanoarrays (CPIN nanoarrays) comprised of nanoparticles of inorganic Li+ insertion compounds that are “wired” together with oligomeric chains of derivatives of polythiophene. Using these nanoarrays, we developed an understanding of the relationship between structure and electrochemical function for nanostructured materials. Such nanoarrays are expected to have extremely high specific energy and specific power for battery applications due to the unique structural characteristics that derive from the nanoarray. Under this award we developed several synthetic approaches to producing manganese dioxide nanoparticles (NPs). We also developed a layer-by-layer approach for immobilizing these NPs so they could be examined electrochemically. We also developed new synthetic procedures for encapsulating manganese dioxide nanoparticles within spheres of polyethylenedioxythiophene (PEDOT), a conducting polymer with excellent charge-discharge stability. These have a unique manganese dioxide core-PEDOT shell structure. We examined the structures of these systems using transmission electron microscopy, various scanning probe microscopies, and electrochemical measurements. Various technical reports have been submitted that describe the work, including conference presentations, publications and patent applications. These reports are available through http://www.osti.gov, the DOE Energy Link System.
Date: June 27, 2006
Creator: Buttry, Daniel A.
Object Type: Report
System: The UNT Digital Library
Wolter X-Ray Microscope Computed Tomography Ray-Trace Model with Preliminary Simulation Results (open access)

Wolter X-Ray Microscope Computed Tomography Ray-Trace Model with Preliminary Simulation Results

It is proposed to build a Wolter X-ray Microscope Computed Tomography System in order to characterize objects to sub-micrometer resolution. Wolter Optics Systems use hyperbolic, elliptical, and/or parabolic mirrors to reflect x-rays in order to focus or magnify an image. Wolter Optics have been used as telescopes and as microscopes. As microscopes they have been used for a number of purposes such as measuring emission x-rays and x-ray fluoresce of thin biological samples. Standard Computed Tomography (CT) Systems use 2D radiographic images, from a series of rotational angles, acquired by passing x-rays through an object to reconstruct a 3D image of the object. The x-ray paths in a Wolter X-ray Microscope will be considerably different than those of a standard CT system. There is little information about the 2D radiographic images that can be expected from such a system. There are questions about the quality, resolution and focusing range of an image created with such a system. It is not known whether characterization information can be obtained from these images and whether these 2D images can be reconstructed to 3D images of the object. A code has been developed to model the 2D radiographic image created by an object in …
Date: February 27, 2006
Creator: Jackson, J A
Object Type: Report
System: The UNT Digital Library
Realistic Two-body Interactions in Many-nucleon Systems: Correlated Motion beyond Single-particle Behavior (open access)

Realistic Two-body Interactions in Many-nucleon Systems: Correlated Motion beyond Single-particle Behavior

In the framework of the theory of spectral distributions we perform an overall comparison of three modern realistic interactions, CD-Bonn, CD-Bonn+3terms, and GXPF1 in a broad range of nuclei in the upper fp shell and study their ability to account for the development of isovector pairing correlations and collective rotational motion in many-particle nuclear systems. Our findings reveal a close similarity between CD-Bonn and CD-Bonn+3terms, while both interactions possess features different from the ones of GXPF1. The GXPF1 interaction is used to determine the strength parameter of a quadrupole term that augments an isovector-pairing model interaction with Sp(4) dynamical symmetry, which in turn is shown to yield a reasonable agreement with the experimental low-lying energy spectra of {sup 58}Ni and {sup 58}Cu.
Date: June 27, 2006
Creator: Sviratcheva, K.D.; Draayer, J.P. & /Louisiana State U. /Iowa State U. /LLNL, Livermore /SLAC
Object Type: Report
System: The UNT Digital Library
Surface structure of CdSe Nanorods revealed by combined X-rayabsorption fine structure measurements and ab-initio calculations (open access)

Surface structure of CdSe Nanorods revealed by combined X-rayabsorption fine structure measurements and ab-initio calculations

We report orientation-specific, surface-sensitive structural characterization of colloidal CdSe nanorods with extended X-ray absorption fine structure spectroscopy and ab-initio density functional theory calculations. Our measurements of crystallographically-aligned CdSe nanorods show that they have reconstructed Cd-rich surfaces. They exhibit orientation-dependent changes in interatomic distances which are qualitatively reproduced by our calculations. These calculations reveal that the measured interatomic distance anisotropy originates from the nanorod surface.
Date: January 27, 2006
Creator: Aruguete, Deborah A.; Marcus, Matthew A.; Li, Liang-shi; Williamson, Andrew; Fakra, Sirine; Gygi, Francois et al.
Object Type: Article
System: The UNT Digital Library
Remaining Sites Verification Package for the 100-B-20, 1716-B Maintenance Garage Underground Tank, Waste Site Reclassification Form 2006-019 (open access)

Remaining Sites Verification Package for the 100-B-20, 1716-B Maintenance Garage Underground Tank, Waste Site Reclassification Form 2006-019

The 100-B-20 waste site, located in the 100-BC-1 Operable Unit of the Hanford Site, consisted of an underground oil tank that once serviced the 1716-B Maintenance Garage. The selected action for the 100-B-20 waste site involved removal of the oil tanks and their contents and demonstrating through confirmatory sampling that all cleanup goals have been met. In accordance with this evaluation, a reclassification status of interim closed out has been determined. The results demonstrate that the site will support future unrestricted land uses that can be represented by a rural-residential scenario. These results also show that residual concentrations support unrestricted future use of shallow zone soil and that contaminant levels remaining in the soil are protective of groundwater and the Columbia River.
Date: September 27, 2006
Creator: Dittmer, L. M.
Object Type: Report
System: The UNT Digital Library
Decontamination of Zircaloy Spent Fuel Cladding Hulls (open access)

Decontamination of Zircaloy Spent Fuel Cladding Hulls

The reprocessing of commercial spent nuclear fuel (SNF) generates a Zircaloy cladding hull waste which requires disposal as a high level waste in the geologic repository. The hulls are primarily contaminated with fission products and actinides from the fuel. During fuel irradiation, these contaminants are deposited in a thin layer of zirconium oxide (ZrO{sub 2}) which forms on the cladding surface at the elevated temperatures present in a nuclear reactor. Therefore, if the hulls are treated to remove the ZrO{sub 2} layer, a majority of the contamination will be removed and the hulls could potentially meet acceptance criteria for disposal as a low level waste (LLW). Discard of the hulls as a LLW would result in significant savings due to the high costs associated with geologic disposal. To assess the feasibility of decontaminating spent fuel cladding hulls, two treatment processes developed for dissolving fuels containing zirconium (Zr) metal or alloys were evaluated. Small-scale dissolution experiments were performed using the ZIRFLEX process which employs a boiling ammonium fluoride (NH{sub 4}F)/ammonium nitrate (NH{sub 4}NO{sub 3}) solution to dissolve Zr or Zircaloy cladding and a hydrofluoric acid (HF) process developed for complete dissolution of Zr-containing fuels. The feasibility experiments were performed using Zircaloy-4 …
Date: September 27, 2006
Creator: Rudisill, T. & John Mickalonis, J.
Object Type: Report
System: The UNT Digital Library
Interpolation of probability densities in ENDF and ENDL (open access)

Interpolation of probability densities in ENDF and ENDL

Suppose that we are given two probability densities p{sub 0}(E{prime}) and p{sub 1}(E{prime}) for the energy E{prime} of an outgoing particle, p{sub 0}(E{prime}) corresponding to energy E{sub 0} of the incident particle and p{sub 1}(E{prime}) corresponding to incident energy E{sub 1}. If E{sub 0} < E{sub 1}, the problem is how to define p{sub {alpha}}(E{prime}) for intermediate incident energies E{sub {alpha}} = (1 - {alpha})E{sub 0} + {alpha}E{sub 1} with 0 < {alpha} < 1. In this note the author considers three ways to do it. They begin with unit-base interpolation, which is standard in ENDL and is sometimes used in ENDF. They then describe the equiprobable bins used by some Monte Carlo codes. They then close with a discussion of interpolation by corresponding-points, which is commonly used in ENDF.
Date: January 27, 2006
Creator: Hedstrom, G
Object Type: Report
System: The UNT Digital Library
Screening and Ranking Framework (SRF) for Geologic CO2 Storage Site Selection on the Basis of Hse Risk (open access)

Screening and Ranking Framework (SRF) for Geologic CO2 Storage Site Selection on the Basis of Hse Risk

A screening and ranking framework (SRF) has been developedto evaluate potential geologic carbon dioxide (CO2) storage sites on thebasis of health, safety, and environmental (HSE) risk arising from CO2leakage. The approach is based on the assumption that CO2 leakage risk isdependent on three basic characteristics of a geologic CO2 storage site:(1) the potential for primary containment by the target formation; (2)the potential for secondary containment if the primary formation leaks;and (3) the potential for attenuation and dispersion of leaking CO2 ifthe primary formation leaks and secondary containment fails. Theframework is implemented in a spreadsheet in which users enter numericalscores representing expert opinions or published information along withestimates of uncertainty. Applications to three sites in Californiademonstrate the approach. Refinements and extensions are possible throughthe use of more detailed data or model results in place of propertyproxies.
Date: November 27, 2006
Creator: Oldenburg, Curtis M.
Object Type: Article
System: The UNT Digital Library
d-alpha correlation functions and collective motion in Xe+Au collisions at E/A=50 MeV (open access)

d-alpha correlation functions and collective motion in Xe+Au collisions at E/A=50 MeV

The interplay of the effects of geometry and collective motion on d-{alpha} correlation functions is investigated for central Xe+Au collisions at E/A=50 MeV. The data cannot be explained with out collective motion, which could be partly along the beam axis. A semi-quantitative description of the data can be obtained using a Monte -Carlo model, where thermal emission is superimposed on collective motion. Both the emission volume and the competition between the thermal and collective motion influence significantly the shape of the correlation function, motivating new strategies for extending intensity interferometry studies to massive particles.
Date: July 27, 2006
Creator: Verde, G.; Danielewicz, P.; Lynch, W.; Chan, C.; Gelbke, C.; Kwong, L. et al.
Object Type: Article
System: The UNT Digital Library
Exact solutions in a model of vertical gas migration (open access)

Exact solutions in a model of vertical gas migration

This work is motivated by the growing interest in injectingcarbon dioxide into deep geological formations as a means of avoidingatmospheric emissions of carbon dioxide and consequent global warming.One of the key questions regarding the feasibility of this technology isthe potential rate of leakage out of the primary storage formation. Weseek exact solutions in a model of gas flow driven by a combination ofbuoyancy, viscous and capillary forces. Different combinations of theseforces and characteristic length scales of the processes lead todifferent time scaling and different types of solutions. In the case of athin, tight seal, where the impact of gravity is negligible relative tocapillary and viscous forces, a Ryzhik-type solution implies square-rootof time scaling of plume propagation velocity. In the general case, a gasplume has two stable zones, which can be described by travelling-wavesolutions. The theoretical maximum of the velocity of plume migrationprovides a conservative estimate for the time of vertical migration.Although the top of the plume has low gas saturation, it propagates witha velocity close to the theoretical maximum. The bottom of the plumeflows significantly more slowly at a higher gas saturation. Due to localheterogeneities, the plume can break into parts. Individual plumes alsocan coalesce and from larger plumes. The …
Date: June 27, 2006
Creator: Silin, Dmitriy B.; Patzek, Tad W. & Benson, Sally M.
Object Type: Article
System: The UNT Digital Library