Resource Type

The phylogeny of Nudibranchia (Opisthobranchia, Gastropoda, Mollusca) reconstructed by three molecular markers (open access)

The phylogeny of Nudibranchia (Opisthobranchia, Gastropoda, Mollusca) reconstructed by three molecular markers

None
Date: December 31, 2001
Creator: Wollscheid-Lengeling, Evi; Boore, Jeffrey L.; Brown, Wesley M. & Wagele, Heike
System: The UNT Digital Library
Jet tomography of hot and cold nuclear matter (open access)

Jet tomography of hot and cold nuclear matter

None
Date: December 30, 2001
Creator: Wang, Enke & Wang, Xin-Nian
System: The UNT Digital Library
Benchmarking and tuning the MILC code on clusters and supercomputers (open access)

Benchmarking and tuning the MILC code on clusters and supercomputers

Recently, we have benchmarked and tuned the MILC code on a number of architectures including Intel Itanium and Pentium IV (PIV), dual-CPU Athlon, and the latest Compaq Alpha nodes. Results will be presented for many of these, and we shall discuss some simple code changes that can result in a very dramatic speedup of the KS conjugate gradient on processors with more advanced memory systems such as PIV, IBM SP and Alpha.
Date: December 28, 2001
Creator: Gottlieb, Steven A.
System: The UNT Digital Library
Cost of dynamical quark simulations with improved staggered quarks (open access)

Cost of dynamical quark simulations with improved staggered quarks

The cost of dynamical quark simulations with improved staggered quarks is estimated based on current and planned running by the MILC collaboration. I find that a few 10s of Tera op years should be sufficient to calculate down to a lattice spacing of 0.045 fm.
Date: December 28, 2001
Creator: Gottlieb, Steven A
System: The UNT Digital Library
In celebration of the fixed target program with the Tevatron (open access)

In celebration of the fixed target program with the Tevatron

The Tevatron is the world's first large superconducting accelerator. With its construction, we gained the dual opportunities to advance the state of the art in accelerator technology with the machine itself and in particle physics with the experiments that became possible in a higher energy regime. There have been 43 experiments in the Tevatron fixed target program. Many of these are better described as experimental programs, each with a broad range of physics goals and results, and more than 100 collaborating physicists and engineers. The results of this program are three-fold: (1) new technologies in accelerators, beams and detectors which advanced the state of the art; (2) new experimental results published in the refereed physics journals; and (3) newly trained scientists who are both the next generation of particle physicists and an important part of the scientific, technical and educational backbone of the country as a whole. In this book they compile these results. There are sections from each experiment including what their physics goals and results were, what papers were published, and which students have received degrees. Summaries of these results from the program as a whole are quite interesting, but the physics results from this program are too …
Date: December 28, 2001
Creator: al., Jeffrey A. Appel et
System: The UNT Digital Library
On the large Nc expansion in quantum chromodynamics (open access)

On the large Nc expansion in quantum chromodynamics

The author discusses methods based on the large Nc expansion to study nonperturbative aspects of quantum chromodynamics, the theory of the strong force. The author applies these methods to the analysis of weak decay processes and the nonperturbative computation of the weak matrix elements needed for a complete evaluation of these decays in the Standard Model of elementary particle physics.
Date: December 28, 2001
Creator: Bardeen, William A.
System: The UNT Digital Library
Recent QCD results from CDF (open access)

Recent QCD results from CDF

Experimental results on QCD measurements obtained in recent analyses and based on data collected with CDF Detector from the Run 1b Tevatron running cycle are presented. The scope of the talk includes major QCD topics: a measurement of the strong coupling constant {alpha}{sub s}, extracted from inclusive jet spectra and the underlying event energy contribution to a jet cone. Another experimental object of QCD interest, prompt photon production, is also discussed and the updated measurements by CDF of the inclusive photon cross section at 630 GeV and 1800 GeV, and the comparison with NLO QCD predictions is presented.
Date: December 28, 2001
Creator: Gorelov, I.
System: The UNT Digital Library
Superconducting superferric dipole magnet with cold iron core for the VLHC (open access)

Superconducting superferric dipole magnet with cold iron core for the VLHC

The magnet system of the Very Large Hadron Collider (VLHC) Stage I is based on a superconducting 2 Tesla magnetic field combined function magnets. These magnets will have a room temperature iron core with two 20 mm air gaps. Magnetic field in both horizontally separated air gaps is excited by a single turn 100 kA superconducting transmission line. The alternative design with cold iron core, horizontally or vertically separated air gaps is under investigation. The cold iron option with horizontally separated air gaps reduces the amount of iron, which is one of the main cost driver for 233 km length magnet system of the future accelerator. The vertical beam separation decreases volume superconductor, heat load from synchrotron radiation and eliminates fringing field from a return bus. But the horizontal beam separation has lowest volume of iron core and as a result lower heat load for cryosystem during cooling down. All these options are discussed and comparison is made. Superconducting correction system, combined with the magnet, allowing to increase the maximum field is also under discussion. Preliminary cost analysis are made for all options.
Date: December 28, 2001
Creator: Kashikhin, G.William Foster and Vladimir
System: The UNT Digital Library
Supersymmetry searches at the Collider Detector at Fermilab (open access)

Supersymmetry searches at the Collider Detector at Fermilab

This article presents the current experimental results of searches for Supersymmetry (SUSY) at the Collider Detector at Fermilab (CDF), using over 110 pb{sup -1} of proton-antiproton collision data with {radical}s = 1800 GeV collected during the period 1992-1995. Since no signal was found, limits on the production of supersymmetric particles are derived. The prospects for supersymmetry searches at Run II of the Tevatron, that began in March 2001, are also discussed here.
Date: December 28, 2001
Creator: Tsybychev, D.
System: The UNT Digital Library
D-Zero silicon microstrip tracker for Run IIA (open access)

D-Zero silicon microstrip tracker for Run IIA

We describe the production, installation and commissioning of the new 792,576 channel D0 Silicon Microstrip Tracker to be used for the 2 fb{sup -1} of the Run IIa at the Tevatron.
Date: December 28, 2001
Creator: Kajfasz, Eric
System: The UNT Digital Library
Optimum Vehicle Component Integration with InVeST (Integrated Vehicle Simulation Testbed) (open access)

Optimum Vehicle Component Integration with InVeST (Integrated Vehicle Simulation Testbed)

We have developed an Integrated Vehicle Simulation Testbed (InVeST). InVeST is based on the concept of Co-simulation, and it allows the development of virtual vehicles that can be analyzed and optimized as an overall integrated system. The virtual vehicle is defined by selecting different vehicle components from a component library. Vehicle component models can be written in multiple programming languages running on different computer platforms. At the same time, InVeST provides full protection for proprietary models. Co-simulation is a cost-effective alternative to competing methodologies, such as developing a translator or selecting a single programming language for all vehicle components. InVeST has been recently demonstrated using a transmission model and a transmission controller model. The transmission model was written in SABER and ran on a Sun/Solaris workstation, while the transmission controller was written in MATRIXx and ran on a PC running Windows NT. The demonstration was successfully performed. Future plans include the applicability of Co-simulation and InVeST to analysis and optimization of multiple complex systems, including those of Intelligent Transportation Systems.
Date: December 27, 2001
Creator: Ng, Walter; Paddack, Erma & Aceves, Salvador
System: The UNT Digital Library
RbGd{sub 2}Br{sub 7}:Ce scintillators for gamma ray and thermal neutron detection (open access)

RbGd{sub 2}Br{sub 7}:Ce scintillators for gamma ray and thermal neutron detection

In this paper, we report on gamma ray and thermal neutron detection with RbGd2Br7:Ce scintillators. RbGd2Br7:Ce (RGB) is a new scintillator material, which shows high light output (56,000 photons/MeV) and has a fast principal decay constant (45 ns) when doped with 10 percent Ce. These properties make RGB an attractive scintillator for g-ray detection. Also, due to the presence of Gd as a constituent, RGB has a high cross section for thermal neutron absorption and can achieve close to 100 percent stopping efficiency with 0.5 mm thick RGB crystals. Crystals of RGB with three different Ce concentrations (0.1, 5, and 10 percent) have been grown and their basic scintillation properties such as light output, decay time, and emission spectrum have been measured. In addition, high efficiency thermal neutron detection has been confirmed in our studies.
Date: December 25, 2001
Creator: Shah, Kanai S.; Cirignano, Leonard; Grazioso, Ronald; Klugerman, Misha; Bennett, Paul R.; Gupta, Tapan K. et al.
System: The UNT Digital Library
Adapting MARSSIM for FUSRAP site closure. (open access)

Adapting MARSSIM for FUSRAP site closure.

The Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) provides a coherent, technically defensible process for establishing that exposed surfaces satisfy site cleanup requirements. Unfortunately, many sites have complications that challenge a direct application of MARSSIM. Example complications include Record of Decision (ROD) requirements that are not MARSSIM-friendly, the potential for subsurface contamination, and incomplete characterization information. These types of complications are typically the rule, rather than the exception, for sites undergoing radiologically-driven remediation and closure. One such site is the Formerly Utilized Sites Remedial Action Program (FUSRAP) Linde site in Tonawanda, New York. Cleanup of the site is currently underway. The Linde site presented a number of challenges to designing and implementing a closure strategy consistent with MARSSIM. This paper discusses some of the closure issues confronted by the U.S. Army Corps of Engineers Buffalo District at the Linde site, and describes how MARSSIM protocols were adapted to address these issues.
Date: December 21, 2001
Creator: Johnson, R.; Durham, L.; Rieman, C. & Hoover, R.
System: The UNT Digital Library
"America, Love It or Leave It": Some Native American Initiatives to Move to Mexico, 1890-1940 (open access)

"America, Love It or Leave It": Some Native American Initiatives to Move to Mexico, 1890-1940

Article describes the emigration to Mexico initiative some Native American tribes in Oklahoma considered between 1890 and 1940. Steven Crum also describes the national government's response to these efforts and references the similarity of the 1960s phrase coined in the article's title.
Date: Winter 2001
Creator: Crum, Steven J.
System: The Gateway to Oklahoma History
Celebrating the Library Spirit: A Look Back at the Carnegie Libraries in Oklahoma (open access)

Celebrating the Library Spirit: A Look Back at the Carnegie Libraries in Oklahoma

Article describes the construction of twenty-four libraries in Oklahoma funded by Andrew Carnegie in the early 1900s. Tanya D. Finchum and G. Allen Finchum provide a detailed look at these libraries and their continuing contribution.
Date: Winter 2001
Creator: Finchum, Tanya D. & Finchum, G. Allen
System: The Gateway to Oklahoma History
A Child's Encounter with the Devil: An Unusual Near-Death Experience with Both Blissful and Frightening Elements (open access)

A Child's Encounter with the Devil: An Unusual Near-Death Experience with Both Blissful and Frightening Elements

Abstract: I describe the near-death experience (NDE) of a 6-year-old boy who encountered both the devil and God following a near-fatal car accident, and compare recent recollections of the event with those made four years earlier. I discuss the aftereffects of this experience, and review the findings of earlier studies of frightening NDEs.
Date: Winter 2001
Creator: Bonenfant, Richard J.
System: The UNT Digital Library
Coarse-Grained Molecular Dynamics and Multiscale Modeling of NEMS Resonators (open access)

Coarse-Grained Molecular Dynamics and Multiscale Modeling of NEMS Resonators

We review concurrent multiscale simulations of dynamic and temperature-dependent processes found in nanomechanical systems coupled to larger scale surroundings. We focus on the behavior of sub-micron Micro-Electro-Mechanical Systems (MEMS), especially microresonators. These systems are often called NEMS, for Nano-Electro-Mechanical Systems. The coupling of length scales methodology we have developed for MEMS employs an atomistic description of small but key regions of the system, consisting of millions of atoms, coupled concurrently to a finite element model of the periphery. The model, Coarse-Grained Molecular Dynamics (CGMD), builds a generalized finite element formalism from the underlying atomistic physics in order to ensure a smooth coupling between regions governed by different length scales. The result is a model that accurately describes the behavior of the mechanical components of MEMS down to the atomic scale.
Date: December 21, 2001
Creator: Rudd, R E
System: The UNT Digital Library
Coarse-Grained Molecular Dynamics: Dissipation Due to Internal Modes (open access)

Coarse-Grained Molecular Dynamics: Dissipation Due to Internal Modes

We describe progress on the issue of pathological elastic wave reflection in atomistic and multiscale simulation. First we briefly review Coarse-Grained Molecular Dynamics (CGMD). Originally CGMD was formulated as a Hamiltonian system in which energy is conserved. This formulation is useful for many applications, but recently CGMD has been extended to include generalized Langevin forces. Here we describe how Langevin dynamics arise naturally in CGMD, and we examine the implication for elastic wave scattering.
Date: December 21, 2001
Creator: Rudd, R E
System: The UNT Digital Library
For the Record, Winter 2001-02 (open access)

For the Record, Winter 2001-02

For the Record section including the minutes of the regular quarterly board meeting of the Board of Directors of the Oklahoma Historical Society that was held on July 25, 2001.
Date: Winter 2001
Creator: Oklahoma Historical Society
System: The Gateway to Oklahoma History
Initiation, Growth and Mitigation of UV Laser Induced Damage in Fused Silica (open access)

Initiation, Growth and Mitigation of UV Laser Induced Damage in Fused Silica

Laser damage of large fused silica optics initiates at imperfections. Possible initiation mechanisms are considered. We demonstrate that a model based on nanoparticle explosions is consistent with the observed initiation craters. Possible mechanisms for growth upon subsequent laser irradiation, including material modification and laser intensification, are discussed. Large aperture experiments indicate an exponential increase in damage size with number of laser shots. Physical processes associated with this growth and a qualitative explanation of self-accelerated growth is presented. Rapid growth necessitates damage growth mitigation techniques. Several possible mitigation techniques are mentioned, with special emphasis on CO{sub 2} processing. Analysis of material evaporation, crack healing, and thermally induced stress are presented.
Date: December 21, 2001
Creator: Rubenchik, A M & Feit, M D
System: The UNT Digital Library
Isotopically controlled semiconductors (open access)

Isotopically controlled semiconductors

Semiconductor bulk crystals and multilayer structures with controlled isotopic composition have attracted much scientific and technical interest in the past few years. Isotopic composition affects a large number of physical properties, including phonon energies and lifetimes, bandgaps, the thermal conductivity and expansion coefficient and spin-related effects. Isotope superlattices are ideal media for self-diffusion studies. In combination with neutron transmutation doping, isotope control offers a novel approach to metal-insulator transition studies. Spintronics, quantum computing and nanoparticle science are emerging fields using isotope control.
Date: December 21, 2001
Creator: Haller, Eugene E.
System: The UNT Digital Library
The Life of Littleton Horace Davis: Pistol Packin' Preacher and Railroad Man (open access)

The Life of Littleton Horace Davis: Pistol Packin' Preacher and Railroad Man

Article covers the life of minister, farmer, rail car inspector, and community leader L. H. Davis. Frank W. Davis relates the contributions his grandfather made, including building the first two-story house in Francis, Oklahoma, the founding of the Francis Methodist Episcopal Church, and acquiring a reputation as a fearless man even during the dangerous railroad strikes of 1922.
Date: Winter 2001
Creator: Davis, Frank W.
System: The Gateway to Oklahoma History
Modeling of the Deformation of Living Cells Induced by Atomic Force Microscopy (open access)

Modeling of the Deformation of Living Cells Induced by Atomic Force Microscopy

We describe finite element modeling of the deformation of living cells by atomic force microscopy (AFM). Cells are soft systems, susceptible to large deformations in the course of an AFM measurement. Often the local properties, the subject of the measurement, are obscured by the response of the cell as a whole. The Lagrangian finite deformation model we have developed and implemented in finite elements analysis offers a solution to this problem. The effect of the gross deformation of the cell can be subtracted from the experimentally measured data in order to give a reproducible value for local properties. This facilitates concurrent experimental efforts to measure the mechanical properties at specific receptor sites on the membrane of a living cell.
Date: December 21, 2001
Creator: Rudd, Robert E.; McElfresh, Michael; Baesu, Eveline; Balhorn, Rod; Allen, Michael J. & Belak, James
System: The UNT Digital Library
Notes and Documents, Winter 2001-02 (open access)

Notes and Documents, Winter 2001-02

Notes and Documents column including a document honoring Daniel F. Littlefield, Jr., who was inducted into the Oklahoma Historians Hall of Fame in 2001. It also includes a document about a letter Woodie Guthrie wrote to his first niece, Mary Ann Guthrie, which was donated and included.
Date: Winter 2001
Creator: Armstrong, Connie G. & Blochowiak, Mary Ann
System: The Gateway to Oklahoma History