Measurements and Phenomenological Modeling of Magnetic FluxBuildup in Spheromak Plasmas (open access)

Measurements and Phenomenological Modeling of Magnetic FluxBuildup in Spheromak Plasmas

Internal magnetic field measurements and high-speed imaging at the Sustained Spheromak Physics Experiment (SSPX) [E. B. Hooper, L. D. Pearlstein, R. H. Bulmer, Nucl. Fusion 39, 863 (1999)] are used to study spheromak formation and field buildup. The measurements are analyzed in the context of a phenomenological model of magnetic helicity based on the topological constraint of minimum helicity in the open flux before reconnecting and linking closed flux. Two stages are analyzed: (1) the initial spheromak formation, i. e. when all flux surfaces are initially open and reconnect to form open and closed flux surfaces, and (2) the stepwise increase of closed flux when operating the gun on a new mode that can apply a train of high-current pulses to the plasma. In the first stage, large kinks in the open flux surfaces are observed in the high-speed images taken shortly after plasma breakdown, and coincide with large magnetic asymmetries recorded in a fixed insertable magnetic probe that spans the flux conserver radius. Closed flux (in the toroidal average sense) appears shortly after this. This stage is also investigated using resistive magnetohydrodynamic simulations. In the second stage, a time lag in response between open and closed flux surfaces after …
Date: December 14, 2007
Creator: Romero-Talamas, C. A.; Hooper, E. B.; Jayakumar, R.; McLean, H. S.; Wood, R. D. & Moller, J. M.
Object Type: Article
System: The UNT Digital Library
New and Novel Nondestructive Neutron and Gamma-Ray Technologies Applied to Safeguards (open access)

New and Novel Nondestructive Neutron and Gamma-Ray Technologies Applied to Safeguards

None
Date: December 14, 2007
Creator: Dougan, A. D.; Snyderman, N. J.; Nakae, L. F.; Dietrich, D. D.; Kerr, P. L.; Wang, T. F. et al.
Object Type: Article
System: The UNT Digital Library
Non-Relativistic Superstring Theories (open access)

Non-Relativistic Superstring Theories

We construct a supersymmetric version of the 'critical' non-relativistic bosonic string theory [1] with its manifest global symmetry. We introduce the anticommuting bc CFT which is the super partner of the {beta}{gamma} CFT. The conformal weights of the b and c fields are both 1/2. The action of the fermionic sector can be transformed into that of the relativistic superstring theory. We explicitly quantize the theory with manifest SO(8) symmetry and find that the spectrum is similar to that of Type IIB superstring theory. There is one notable difference: the fermions are non-chiral. We further consider 'noncritical' generalizations of the supersymmetric theory using the superspace formulation. There is an infinite range of possible string theories similar to the supercritical string theories. We comment on the connection between the critical non-relativistic string theory and the lightlike Linear Dilaton theory.
Date: December 14, 2007
Creator: Kim, Bom Soo
Object Type: Article
System: The UNT Digital Library
Report Initial Work on Developing Plasma Modeling Capability in WARP for NDCX Experiments (open access)

Report Initial Work on Developing Plasma Modeling Capability in WARP for NDCX Experiments

This milestone has been accomplished. The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) has developed and implemented an initial beam-in-plasma implicit modeling capability in Warp; has carried out tests validating the behavior of the models employed; has compared the results of electrostatic and electromagnetic models when applied to beam expansion in an NDCX-I relevant regime; has compared Warp and LSP results on a problem relevant to NDCX-I; has modeled wave excitation by a rigid beam propagating through plasma; and has implemented and begun testing a more advanced implicit method that correctly captures electron drift motion even when timesteps too large to resolve the electron gyro-period are employed. The HIFS-VNL is well on its way toward having a state-of-the-art source-to-target simulation capability that will enable more effective support of ongoing experiments in the NDCX series and allow more confident planning for future ones.
Date: December 14, 2007
Creator: Friedman, A; Cohen, R H; Grote, D P & Vay, J
Object Type: Report
System: The UNT Digital Library
Three-dimensional Dielectric Photonic Crystal Structures for Laser-driven Acceleration (open access)

Three-dimensional Dielectric Photonic Crystal Structures for Laser-driven Acceleration

We present the design and simulation of a three-dimensional photonic crystal waveguide for linear laser-driven acceleration in vacuum. The structure confines a synchronous speed-of-light accelerating mode in both transverse dimensions. We report the properties of this mode, including sustainable gradient and optical-to-beam efficiency. We present a novel method for confining a particle beam using optical fields as focusing elements. This technique, combined with careful structure design, is shown to have a large dynamic aperture and minimal emittance growth, even over millions of optical wavelengths.
Date: December 14, 2007
Creator: Cowan, Benjamin M. & /Tech-X, Boulder /SLAC
Object Type: Article
System: The UNT Digital Library
Unique Identification of Lee-Wick Gauge Bosons at Linear Colliders (open access)

Unique Identification of Lee-Wick Gauge Bosons at Linear Colliders

Grinstein, O'Connell and Wise have recently presented an extension of the Standard Model (SM), based on the ideas of Lee and Wick (LW), which demonstrates an interesting way to remove the quadratically divergent contributions to the Higgs mass induced by radiative corrections. This model predicts the existence of negative-norm copies of the usual SM fields at the TeV scale with ghost-like propagators and negative decay widths, but with otherwise SM-like couplings. In earlier work, it was demonstrated that the LW states in the gauge boson sector of these models, though easy to observe, cannot be uniquely identified as such at the LHC. In this paper, we address the issue of whether or not this problem can be resolved at an e{sup +}e{sup -} collider with a suitable center of mass energy range. We find that measurements of the cross section and the left-right polarization asymmetry associated with Bhabha scattering can lead to a unique identification of the neutral electroweak gauge bosons of the Lee-Wick type.
Date: December 14, 2007
Creator: Rizzo, Thomas G.
Object Type: Article
System: The UNT Digital Library
Use of ARM Data to address the Climate Change Further Development and Applications of A Multi-scale Modeling Framework (open access)

Use of ARM Data to address the Climate Change Further Development and Applications of A Multi-scale Modeling Framework

The Colorado State University (CSU) Multi-scale Modeling Framework (MMF) is a new type of general circulation model (GCM) that replaces the conventional parameterizations of convection, clouds and boundary layer with a cloud-resolving model (CRM) embedded into each grid column. The MMF that we have been working with is a “super-parameterized” version of the Community Atmosphere Model (CAM). As reported in the publications listed below, we have done extensive work with the model. We have explored the MMF’s performance in several studies, including an AMIP run and a CAPT test, and we have applied the MMF to an analysis of climate sensitivity.
Date: December 14, 2007
Creator: Randall, David A. & Khairoutdinov, Marat
Object Type: Report
System: The UNT Digital Library
Characterization of a Tunable Quasi-Monoenergetic Neutron Beamfrom Deuteron Breakup (open access)

Characterization of a Tunable Quasi-Monoenergetic Neutron Beamfrom Deuteron Breakup

A neutron irradiation facility is being developed at the88-Inch Cyclotron at Lawrence Berkeley National Laboratory for thepurposes of measuring neutron reaction cross sections on radioactivetargets and for radiation effects testing. Applications are of benefit tostockpile stewardship, nuclear astrophysics, next generation advancedfuel reactors, and cosmic radiation biology and electronics in space. Thefacility will supply a tunable, quasi-monoenergetic neutron beam in therange of 10-30 MeV or a white neutron source, produced by deuteronbreakup reactions on thin and thick targets, respectively. Because thedeuteron breakup reaction has not been well studied at intermediateincident deuteron energies, above the target Coulomb barrier and below 56MeV, a detailed characterization was necessary of the neutron spectraproduced by thin targets.Neutron time of flight (TOF) methods have beenused to measure the neutron spectra produced on thin targets of low-Z(titanium) and high-Z (tantalum) materials at incident deuteron energiesof 20 MeV and 29 MeV at 0 deg. Breakup neutrons at both energies fromlow-Z targets appear to peak at roughly half of the available kineticenergy, while neutrons from high-Z interactions peak somewhat lower inenergy, owing to the increased proton energy due to breakup within theCoulomb field. Furthermore, neutron spectra appear narrower for high-Ztargets. These centroids are consistent with recent preliminary protonenergy measurements using …
Date: December 14, 2006
Creator: Bleuel, D. L.; McMahan, M. A.; Ahle, L.; Barquest, B. R.; Cerny, J.; Heilbronn, L. H. et al.
Object Type: Article
System: The UNT Digital Library
LEGACY MANAGEMENT REQUIRES INFORMATION (open access)

LEGACY MANAGEMENT REQUIRES INFORMATION

''Legacy Management Requires Information'' describes the goal(s) of the US Department of Energy's Office of Legacy Management (LM) relative to maintaining critical records and the way those goals are being addressed at Hanford. The paper discusses the current practices for document control, as well as the use of modern databases for both storing and accessing the data to support cleanup decisions. In addition to the information goals of LM, the Hanford Federal Facility Agreement and Consent Order, known as the ''Tri-Party Agreement'' (TPA) is one of the main drivers in documentation and data management. The TPA, which specifies discrete milestones for cleaning up the Hanford Site, is a legally binding agreement among the US Department of Energy (DOE), the Washington State Department of Ecology (Ecology), and the US Environmental Protection Agency (EPA). The TPA requires that DOE provide the lead regulatory agency with the results of analytical laboratory and non-laboratory tests/readings to help guide them in making decisions. The Agreement also calls for each signatory to preserve--for at least ten years after the Agreement has ended--all of the records in its or its contractors, possession related to sampling, analysis, investigations, and monitoring conducted. The tools used at Hanford to meet …
Date: December 14, 2006
Creator: CONNELL, C.W. & HILDEBRAND, R.D.
Object Type: Article
System: The UNT Digital Library
Nanostructured Composite Electrodes for Lithium Batteries (Final Technical Report) (open access)

Nanostructured Composite Electrodes for Lithium Batteries (Final Technical Report)

The objective of this study was to explore new ways to create nanostructured electrodes for rechargeable lithium batteries. Of particular interests are unique nanostructures created by electrochemical deposition, etching and combustion chemical vapor deposition (CCVD). Three-dimensional nanoporous Cu6Sn5 alloy has been successfully prepared using an electrochemical co-deposition process. The walls of the foam structure are highly-porous and consist of numerous small grains. This represents a novel way of creating porous structures that allow not only fast transport of gas and liquid but also rapid electrochemical reactions due to high surface area. The Cu6Sn5 samples display a reversible capacity of {approx}400 mAhg-1. Furthermore, these materials exhibit superior rate capability. At a current drain of 10 mA/cm2(20C rate), the obtainable capacity was more than 50% of the capacity at 0.5 mA/cm2 (1C rate). Highly open and porous SnO2 thin films with columnar structure were obtained on Si/SiO2/Au substrates by CCVD. The thickness was readily controlled by the deposition time, varying from 1 to 5 microns. The columnar grains were covered by nanoparticles less than 20 nm. These thin film electrodes exhibited substantially high specific capacity. The reversible specific capacity of {approx}3.3 mAH/cm2 was demonstrated for up to 80 cycles at a charge/discharge …
Date: December 14, 2006
Creator: Liu, Meilin
Object Type: Report
System: The UNT Digital Library
A Probabilistic Approach to Classifying Supernovae UsingPhotometric Information (open access)

A Probabilistic Approach to Classifying Supernovae UsingPhotometric Information

This paper presents a novel method for determining the probability that a supernova candidate belongs to a known supernova type (such as Ia, Ibc, IIL, etc.), using its photometric information alone. It is validated with Monte Carlo, and both space- and ground-based data. We examine the application of the method to well-sampled as well as poorly sampled supernova light curves and investigate to what extent the best currently available supernova models can be used for typing supernova candidates. Central to the method is the assumption that a supernova candidate belongs to a group of objects that can be modeled; we therefore discuss possible ways of removing anomalous or less well understood events from the sample. This method is particularly advantageous for analyses where the purity of the supernova sample is of the essence, or for those where it is important to know the number of the supernova candidates of a certain type (e.g., in supernova rate studies).
Date: December 14, 2006
Creator: Kuznetsova, Natalia V. & Connolly, Brian M.
Object Type: Article
System: The UNT Digital Library
Radiation Damage Effects on the Magnetic Properties of Pu(1-x)Am(x) (x=0.224) (open access)

Radiation Damage Effects on the Magnetic Properties of Pu(1-x)Am(x) (x=0.224)

Pu(Am) is stable in the fcc {delta}-phase from a few atomic percent to nearly 80 atomic percent Am, expanding the average interatomic separation as the alloy concentration of Am increases. Both Pu and Am spontaneously decay by {alpha}-emission creating self-damage in the lattice in the form of vacancy-interstitial pairs and their aggregates. At sufficiently low temperatures, the damage is frozen in place, but can be removed by thermal annealing at sufficiently high temperatures, effectively resetting the system to an undamaged condition. The magnetic susceptibility and magnetization are observed to increase systematically as a function of accumulated damage in the fcc {delta}-Pu{sub 1-x}Am{sub x} (x=0.224). Some results of these observations are reported here.
Date: December 14, 2006
Creator: McCall, S K; Fluss, M J; Chung, B W; McElfresh, M W & Haire, R G
Object Type: Article
System: The UNT Digital Library
Sister Lab Program Prospective Partner Nuclear Profile: Indonesia (open access)

Sister Lab Program Prospective Partner Nuclear Profile: Indonesia

Indonesia has participated in cooperative technical programs with the IAEA since 1957, and has cooperated with regional partners in all of the traditional areas where nuclear science is employed: in medicine, public health (such as insect control and eradication programs), agriculture (e.g. development of improved varieties of rice), and the gas and oil industries. Recently, Indonesia has contributed significantly to the Reduced Enrichment Research and Training Reactor (RERTR) Program by conducting experiments to confirm the feasibility of Mo-99 production using high-density low enriched uranium (LEU) fuel, a primary goal of the RERTR Program. Indonesia's first research reactor, the TRIGA Mark II at Bandung, began operation in 1964 at 250 kW and was subsequently upgraded in 1971 to 1 MW and further upgraded in 2000 to 2 MW. This reactor was joined by another TRIGA Mark II, the 100-kW Kartini-PPNY at Yogyakarta, in 1979, and by the 30-MW G.A. Siwabessy multipurpose reactor in Serpong, which achieved criticality in July 1983. A 10-MW radioisotope production reactor, to be called the RPI-10, also was proposed for construction at Serpong in the late 1990s, but the project apparently was not carried out. In the five decades since its nuclear research program began, Indonesia has …
Date: December 14, 2006
Creator: Bissani, M & Tyson, S
Object Type: Report
System: The UNT Digital Library
Sister Lab Program Prospective Partner Nuclear Profile: Malaysia (open access)

Sister Lab Program Prospective Partner Nuclear Profile: Malaysia

The Malaysian Deputy Prime Minister Tun Dr Ismail Abdul Rahman suggested in the early 1970s that Malaysia should have a role in the development of nuclear science and technology for peaceful purposes. Accordingly, the Center for the Application of Nuclear Energy (CRANE) was established, with a focus on the development of a scientific and technical pool critical to a national nuclear power program. The Malaysian Cabinet next established the Tun Ismail Atomic Research Center (TIARC) under the Ministry of Science, Technology and the Environment on 19 September 1972, at a site in Bangi, about 35 km south of Kuala Lampur. On 28 June 1982, the PUSPATI reactor, a 1-MW TRIGA MK-II research reactor, first reached criticality. On 10 August 1994, TIARC was officially renamed as the Malaysian Institute for Nuclear Technology Research (MINT). In addition to radioisotope production and neutron radiography conducted at the PUSPATI research reactor, MINT also supports numerous programs employing nuclear technology for medicine, agriculture and industry, and has been involved in both bilateral and multilateral technical cooperation to extend its capabilities. As an energy exporting country, Malaysia has felt little incentive to develop a nuclear energy program, and high level opposition within the government discouraged it …
Date: December 14, 2006
Creator: Bissani, M & Tyson, S
Object Type: Report
System: The UNT Digital Library
Sister Lab Program Prospective Partner Nuclear Profile: Vietnam (open access)

Sister Lab Program Prospective Partner Nuclear Profile: Vietnam

Vietnam's nuclear program began in the 1960s with the installation at Dalat of a 250 kW TRIGA Mk-II research reactor under the U.S. Atoms for Peace Program. The reactor was shut down and its core removed only a few years later, and the nuclear research program was suspended until after the end of the civil war in the late 1970s. The Soviet Union assisted Vietnam in restoring the Dalat reactor to an operational status in 1984, trained a cadre of scientific and technical staff in its operation, and contributed to the development of nuclear science for the medical and agricultural sectors. In the agricultural area in particular, Vietnamese experts have been very successful in developing mutant strains of rice, and continue to work with the IAEA to yield strains that have a shorter growing period, increased resistance to disease, and other desirable characteristics. Rice has always been the main crop in Vietnam, but technical cooperation with the IAEA and other states has enabled the country to become one of the top rice producers in the world, exporting much of its annual crop to over two dozen countries annually. More recently, Vietnam's government has shown increasing interest in developing a civil …
Date: December 14, 2006
Creator: Bissani, M & Tyson, S
Object Type: Report
System: The UNT Digital Library
Synchronous Parallel Kinetic Monte Carlo (open access)

Synchronous Parallel Kinetic Monte Carlo

A novel parallel kinetic Monte Carlo (kMC) algorithm formulated on the basis of perfect time synchronicity is presented. The algorithm provides an exact generalization of any standard serial kMC model and is trivially implemented in parallel architectures. We demonstrate the mathematical validity and parallel performance of the method by solving several well-understood problems in diffusion.
Date: December 14, 2006
Creator: Mart?nez, E.; Marian, J. & Kalos, M. H.
Object Type: Article
System: The UNT Digital Library
19-electron intermediates in the Ligand Substitution of CpW(CO)3with a Lewis Base (open access)

19-electron intermediates in the Ligand Substitution of CpW(CO)3with a Lewis Base

Odd electron species are important intermediates in organometallic chemistry, participating in a variety of catalytic and electron-transfer reactions which produce stable even-electron products. While electron deficient 17-electron (17e) radicals have been well characterized, the possible existence of short-lived 19-electron (19e) radicals has been a subject of continuing investigation. 19e radicals have been postulated as intermediates in the photochemical ligand substitution and disproportionation reactions of organometallic dimers containing a single metal-metal bond, yet the reactions of these intermediates on diffusion-limited time scales (ns-{micro}s) have never been directly observed. This study resolves the 19e dynamics in the ligand substitution of 17e radicals CpW(CO){sub 3}{sup {sm_bullet}} (Cp = C{sub 5}H{sub 5}) with the Lewis base P(OMe){sub 3}, providing the first complete description 19e reactivity.
Date: December 14, 2005
Creator: Cahoon, James F.; Kling, Matthias F.; Sawyer, Karma R.; Frei,Heinz & Harris, Charles B.
Object Type: Article
System: The UNT Digital Library
Atomic Inference from Weak Gravitational Lensing Data (open access)

Atomic Inference from Weak Gravitational Lensing Data

We present a novel approach to reconstructing the projected mass distribution from the sparse and noisy weak gravitational lensing shear data. The reconstructions are regularized via the knowledge gained from numerical simulations of clusters, with trial mass distributions constructed from n NFW profile ellipsoidal components. The parameters of these ''atoms'' are distributed a priori as in the simulated clusters. Sampling the mass distributions from the atom parameter probability density function allows estimates of the properties of the mass distribution to be generated, with error bars. The appropriate number of atoms is inferred from the data itself via the Bayesian evidence, and is typically found to be small, reecting the quality of the data. Ensemble average mass maps are found to be robust to the details of the noise realization, and succeed in recovering the demonstration input mass distribution (from a realistic simulated cluster) over a wide range of scales. As an application of such a reliable mapping algorithm, we comment on the residuals of the reconstruction and the implications for predicting convergence and shear at specific points on the sky.
Date: December 14, 2005
Creator: Marshall, Phil
Object Type: Article
System: The UNT Digital Library
Beam-Loading Compensation for Super B-Factories (open access)

Beam-Loading Compensation for Super B-Factories

Super B-factory designs under consideration expect to reach luminosities in the 10{sup 35}-10{sup 36} range. The dramatic luminosity increase relative to the existing B-factories is achieved, in part, by raising the beam currents stored in the electron and positron rings. For such machines to succeed it is necessary to consider in the RF system design not only the gap voltage and beam power, but also the beam loading effects. The main effects are the synchronous phase transients due to the uneven ring filling patterns and the longitudinal coupled-bunch instabilities driven by the fundamental impedance of the RF cavities. A systematic approach to predicting such effects and for optimizing the RF system design will be presented. Existing as well as promising new techniques for reducing the effects of heavy beam loading will be described and illustrated with examples from the PEP-II and the KEKB.
Date: December 14, 2005
Creator: Teytelman, D.
Object Type: Article
System: The UNT Digital Library
CKM Parameters and Rare B Decays (open access)

CKM Parameters and Rare B Decays

Measurements of the angles and sides of the unitarity triangle and of the rates of rare B meson decays are crucial for the precise determination of Standard Model parameters and are sensitive to the presence of new physics particles in the loop diagrams. In this paper the recent measurements performed in this area by BABAR and Belle will be presented. The direct measurement of the angle {alpha} is for the first time as precise as the indirect determination. The precision of the |V{sub ub}| determination has improved significantly with respect to previous measurement. New limits on B {yields} {tau}{nu} decays are presented, as well as updated measurements on b {yields} s radiative transitions and a new observation of b {yields} d{gamma} transition made by Belle.
Date: December 14, 2005
Creator: Forti, Francesco
Object Type: Article
System: The UNT Digital Library
A Coherent Compton Backscattering High Gain FEL using an X-Band Microwave Undulator (open access)

A Coherent Compton Backscattering High Gain FEL using an X-Band Microwave Undulator

High power microwave sources at X-Band, delivering 400 to 500 of megawatts for about 400 ns, have been recently developed. These sources can power a microwave undulator with short period and large gap, and can be used in short wavelength FELs reaching the nm region at a beam energy of about 1 GeV. We present here an experiment designed to demonstrate that microwave undulators have the field quality needed for high gain FELs.
Date: December 14, 2005
Creator: Tantawi, S.; Dolgashev, V.; Nantista, C.; Pellegrini, C.; Rosenzweig, J. & Travish, G.
Object Type: Article
System: The UNT Digital Library
Coherent States and Spontaneous Symmetry Breaking in Light Front Scalar Field Theory (open access)

Coherent States and Spontaneous Symmetry Breaking in Light Front Scalar Field Theory

Recently developed nuclear many-body techniques provide novel results when applied to constituent quark models and to light-front scalar field theory. We show how spontaneous symmetry breaking arises and is consistent with a coherent state ansatz in a variational treatment. The kink and the kink-antikink topological features are identified and the onset of symmetry restoration is demonstrated.
Date: December 14, 2005
Creator: Vary, J. P.; Chakrabarti, D.; Harindranath, A.; Lloyd, R.; Martinovic, L. & Spence, J. R.
Object Type: Report
System: The UNT Digital Library
A Coordinated Effort to Improve Parameterization of High-Latitude Cloud and Radiation Processes (open access)

A Coordinated Effort to Improve Parameterization of High-Latitude Cloud and Radiation Processes

The goal of this project is the development and evaluation of improved parameterization of arctic cloud and radiation processes and implementation of the parameterizations into a climate model. Our research focuses specifically on the following issues: (1) continued development and evaluation of cloud microphysical parameterizations, focusing on issues of particular relevance for mixed phase clouds; and (2) evaluation of the mesoscale simulation of arctic cloud system life cycles.
Date: December 14, 2005
Creator: Pinto, J. O.
Object Type: Report
System: The UNT Digital Library
Detection of Laser Optic Defects Using Gradient Direction Matching (open access)

Detection of Laser Optic Defects Using Gradient Direction Matching

That National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) will be the world's largest and most energetic laser. It has thousands of optics and depends heavily on the quality and performance of these optics. Over the past several years, we have developed the NIF Optics Inspection Analysis System that automatically finds defects in a specific optic by analyzing images taken of that optic. This paper describes a new and complementary approach for the automatic detection of defects based on detecting the diffraction ring patterns in downstream optic images caused by defects in upstream optics. Our approach applies a robust pattern matching algorithm for images called Gradient Direction Matching (GDM). GDM compares the gradient directions (the direction of flow from dark to light) of pixels in a test image to those of a specified model and identifies regions in the test image whose gradient directions are most in line with those of the specified model. For finding rings, we use luminance disk models whose pixels have gradient directions all pointing toward the center of the disk. After GDM identifies potential rings locations, we rank these rings by how well they fit the theoretical diffraction ring pattern equation. We perform …
Date: December 14, 2005
Creator: Chen, B Y; Kegelmeyer, L M; Liebman, J A; Salmon, J T; Tzeng, J & Paglieroni, D W
Object Type: Article
System: The UNT Digital Library