Linear Free Energy Relationship Correlation of the Distribution of Solutes between Water and Sodium Dodecyl Sulfate (SDS) Micelles and between Gas and SDS Micelles (open access)

Linear Free Energy Relationship Correlation of the Distribution of Solutes between Water and Sodium Dodecyl Sulfate (SDS) Micelles and between Gas and SDS Micelles

This article discusses linear free energy relationship correlation of the distribution of solutes between water and sodium dodecyl sulfate (SDS) micelles and between gas and SDS micelles.
Date: July 27, 2007
Creator: Sprunger, Laura M.; Acree, William E. (William Eugene) & Abraham, M. H. (Michael H.)
System: The UNT Digital Library
Phase Equilibria in High Energy Density PVDF-Based Polymers (open access)

Phase Equilibria in High Energy Density PVDF-Based Polymers

Article on phase equilibria in high energy density PVDF-based polymers.
Date: July 27, 2007
Creator: Ranjan, Vivek; Yu, Liping; Buongiorno Nardelli, Marco & Bernholc, Jerry
System: The UNT Digital Library
Switchgrass (Panicum virgatum) possesses a divergent family of cinnamoyl CoA reductases with distinct biochemical properties (open access)

Switchgrass (Panicum virgatum) possesses a divergent family of cinnamoyl CoA reductases with distinct biochemical properties

Article on switchgrass (Panicum virgatum) possessing a divergent family of cinnamoyl CoA reductases with distinct biochemical properties.
Date: July 27, 2009
Creator: Escamilla-Treviño, Luis; Shen, Hui; Uppalapati, Srinivasa Rao; Ray, Tui; Tang, Yuhong; Hernandez, Timothy et al.
System: The UNT Digital Library
Kinetic studies of the Cl + HI reaction using three techniques (open access)

Kinetic studies of the Cl + HI reaction using three techniques

Article on kinetic studies of the Cl + HI reaction using three techniques.
Date: July 27, 2004
Creator: Yuan, Jessie; Misra, Ashutosh; Goumri, Abdellatif; Shao, Diane D. & Marshall, Paul
System: The UNT Digital Library
Recent B-physics results at CDF (open access)

Recent B-physics results at CDF

Between 1992 and 1996 CDF collected about 100 pb{sup {minus}1} of data at a {radical}s = 1.8 TeV at the Fermilab Tevatron collider. This data sample led to a large number of precision measurements of B hadrons properties including their masses, lifetimes and neutral B meson oscillation parameters and the discovery of the B{sub c} meson. Here the author reports on three recent results: the measurement of the B{sup +} production cross section, the search for radiative penguin B hadron decays and the measurement of the CP violating parameter sin 2{beta}. These results are significant examples of the breadth of the CDF program. In 2001 the main injector will allow the Tevatron initially to deliver 1 fb{sup {minus}1} per year at {radical}s = 2 TeV. The CDF detector will undergo major upgrades which will further increase the B physics reach.
Date: July 27, 2000
Creator: Bortoletto, Daniela
System: The UNT Digital Library
Preliminary designs for an IR insertion at C-Zero (open access)

Preliminary designs for an IR insertion at C-Zero

Given the advanced state of operational plans for late Run II (132 nsec bunch spacing) the C0 IR insert should be designed to operate such that it does not impact nominal Tevatron parameters. This implies an entirely localized insert -- one which is completely transparent to the rest of the machine. This condition has several important design implications, some of which are pointed out below. An IR design similar to that employed at CDF and D0 is unacceptable as a C0 candidate. The addition of such a (single) low-{beta} region to the machine raises the tune by a half-integer in each plane, moving them far from the standard operating point and right onto the 21.0 integer resonance. The nominal (fractional) operating point is most elegantly maintained by adding 2 local low-{beta} in each plane, thereby boosting the tunes by a full integer. The B0 and D0 IR's are not optically-isolated entities. Progression through the low-{beta}squeeze involves adjusting, not only the main IR quadrupoles, but also the tune quad strings distributed around the ring. The result is that the nominal lattice functions at any point in the ring, and the phase advances across any section of the ring, are not fixed, …
Date: July 27, 2000
Creator: Johnstone, John A.
System: The UNT Digital Library
Radiation in an Emitting and Absorbing Medium: A Gridless Approach (open access)

Radiation in an Emitting and Absorbing Medium: A Gridless Approach

A gridless technique for the solution of the integral form of the radiative heat flux equation for emitting and absorbing media is presented. Treatment of non-uniform absorptivity and gray boundaries is included. As part of this work, the authors have developed fast multipole techniques for extracting radiative heat flux quantities from the temperature fields of one-dimensional and three-dimensional geometries. Example calculations include those for one-dimensional radiative heat transfer through multiple flame sheets, a three-dimensional enclosure with black walls, and an axisymmetric enclosure with black walls.
Date: July 27, 2000
Creator: GRITZO,LOUIS A.; STRICKLAND,JAMES H. & DESJARDIN,PAUL E.
System: The UNT Digital Library
Design of a TRU Waste Repackaging System (open access)

Design of a TRU Waste Repackaging System

This paper addresses the work that SRTC is performing in the design, fabrication, assembly, and testing of the TRU-Waste Repackaging Module.
Date: July 27, 2000
Creator: Fogle, R. F.
System: The UNT Digital Library
Fatigue Damage Accumulation in 63Sn-37Pb Solder Alloy (open access)

Fatigue Damage Accumulation in 63Sn-37Pb Solder Alloy

None
Date: July 27, 2000
Creator: WEI,Y.; CHOW,C.L.; NEILSEN,MICHAEL K. & FANG,HUEI ELIOT
System: The UNT Digital Library
Damage Mechanics Based Fatigue Life Prediction for 63Sn-37Pb Solder Materials (open access)

Damage Mechanics Based Fatigue Life Prediction for 63Sn-37Pb Solder Materials

None
Date: July 27, 2000
Creator: WEI,Y.; CHOW,C.L.; NEILSEN,MICHAEL K. & FANG,HUEI ELIOT
System: The UNT Digital Library
Breeding 10{sup 10}/s Radioactive Nuclei in a Compact Plasma Focus Device (open access)

Breeding 10{sup 10}/s Radioactive Nuclei in a Compact Plasma Focus Device

In the early 90's, it was discovered that a Plasma Focus (PF) system self-creates a plasma-tarp in which high energy-threshold nuclear-reactions occur at high reaction rates. Short life radioisotopes (SLR)s such as {sup 18}F, {sup 17}F, {sup 15}O, {sup 14}O, {sup 13}N have been generated (10{sup 6} - 10{sup 8} per pulse) with a PF-machine using 7 kJ energy storage to produce the plasmas. {beta}{sup -} radioactivity from the SLRs is measured with rugged, Geiger counters inserted into the PF-chamber, and a specific SLR is identified by its half-life. The PF chamber (before discharge) is filled with a mixture of gases that constitutes the latter plasma-target--beam system, e.g., the elements required to produce specific SLRs through nuclear reactions. In this paper, arguments are presented showing that a modest sized PF-machine, using a 50-75 kJ fast capacitor-bank, when operated at pulse frequencies of 1-10 Hz can produce {ge} 10{sup 9} SLRs/pulse. This paper reports the result s of testing a PF as a breeder of SLRs with dual applications for: (1) Secondary Radioactive Nuclear Beams ion-sources (Z < 35), and (2) as a breeder of radioisotopes for biomedicine (Z {le} 10) and/or PET imaging.
Date: July 27, 2001
Creator: Brzosko, JANS.
System: The UNT Digital Library
THE PHENIX EXPERIMENT AT RHIC. (open access)

THE PHENIX EXPERIMENT AT RHIC.

PHENIX is a large detector at the Relativistic Heavy Ion Collider (RHIC) at BNL. RHIC and PHENIX have recently operated for the first time, producing and detecting collisions of gold ions at beam energies of 30 and 65 GeV per nucleon. The current performance and future plans of PHENIX and of RHIC are presented.
Date: July 27, 2000
Creator: ARONSON,S. FOR THE PHENIX COLLABORATION
System: The UNT Digital Library
COUPLED THERMAL-HYDROLOGIC-CHEMICAL (THC) MODEL FOR PLUTONIUM MIGRATION FROM BENHAM UNDERGROUND NUCLEAR TEST. (open access)

COUPLED THERMAL-HYDROLOGIC-CHEMICAL (THC) MODEL FOR PLUTONIUM MIGRATION FROM BENHAM UNDERGROUND NUCLEAR TEST.

None
Date: July 27, 2000
Creator: LICHTNER, PETER C.; ANDREW V. WOLFSBERG, MAUREEN MC GRAW & GLASCOE, LEE
System: The UNT Digital Library
Unstructured Polyhedral Mesh Thermal Radiation Diffusion (open access)

Unstructured Polyhedral Mesh Thermal Radiation Diffusion

Unstructured mesh particle transport and diffusion methods are gaining wider acceptance as mesh generation, scientific visualization and linear solvers improve. This paper describes an algorithm that is currently being used in the KULL code at Lawrence Livermore National Laboratory to solve the radiative transfer equations. The algorithm employs a point-centered diffusion discretization on arbitrary polyhedral meshes in 3D. We present the results of a few test problems to illustrate the capabilities of the radiation diffusion module.
Date: July 27, 2000
Creator: Palmer, T. S.; Zika, M. R. & Madsen, N. K.
System: The UNT Digital Library
A case study in application I/O on Linux clusters. (open access)

A case study in application I/O on Linux clusters.

A critical but often ignored component of system performance is the I/O system. Today's applications expect a great deal from underlying storage systems and software, and both high performance distributed storage and high level interfaces have been developed to fill these needs. In this paper they discuss the I/O performance of a parallel scientific application on a Linux cluster, the FLASH astrophysics code. This application relies on three I/O software components to provide high performance parallel I/O on Linux clusters: the Parallel Virtual File System (PVFS), the ROMIO MPI-IO implementation, and the Hierarchical Data Format (HDF5) library. First they discuss the roles played by each of these components in providing an I/O solution. Next they discuss the FLASH I/O benchmark and point out its relevance. Following this they examine the performance of the benchmark, and through instrumentation of both the application and underlying system software code they discover the location of major software bottlenecks. They work around the most inhibiting of these bottlenecks, showing substantial performance improvement. Finally they point out similarities between the inefficiencies found here and those found in message passing systems, indicating that research in the message passing field could be leveraged to solve similar problems in …
Date: July 27, 2001
Creator: Ross, R.; Nurmi, D.; Cheng, A. & Zingale, M.
System: The UNT Digital Library
Radio-isotope production using laser Wakefield accelerators (open access)

Radio-isotope production using laser Wakefield accelerators

A 10 Hz, 10 TW solid state laser system has been used to produce electron beams suitable for radio-isotope production. The laser beam was focused using a 30 cm focal length f/6 off-axis parabola on a gas plume produced by a high pressure pulsed gas jet. Electrons were trapped and accelerated by high gradient wakefields excited in the ionized gas through the self-modulated laser wakefield instability. The electron beam was measured to contain excesses of 5 nC/bunch. A composite Pb/Cu target was used to convert the electron beam into gamma rays which subsequently produced radio-isotopes through (gamma, n) reactions. Isotope identification through gamma-ray spectroscopy and half-life time measurements demonstrated that Cu{sup 61} was produced which indicates that 20-25 MeV gamma rays were produced, and hence electrons with energies greater than 25-30 MeV. The production of high energy electrons was independently confirmed using a bending magnet spectrometer. The measured spectra had an exponential distribution with a 3 MeV width. The amount of activation was on the order of 2.5 uCi after 3 hours of operation at 1 Hz. Future experiments will aim at increasing this yield by post-accelerating the electron beam using a channel guided laser wakefield accelerator.
Date: July 27, 2001
Creator: Leemans, W. P.; Rodgers, D.; Catravas, P. E.; Geddes, C. G. R.; Fubiani, G.; Toth, C. et al.
System: The UNT Digital Library
Technicolorful Supersymmetry (open access)

Technicolorful Supersymmetry

Technicolor achieves electroweak symmetry breaking (EWSB) in an elegant and natural way, while it suffers from severe model building difficulties. I propose to abandon its secondary goal to eliminate scalar bosons in exchange of solving numerous problems using supersymmetry. It helps to understand walking dynamics much better with certain exact results. In the particular model presented here, there is no light elementary Higgs boson and the EWSB is fully dynamical, hence explaining the hierarchy; There is no alignment problem and no light pseudo-Nambu-Goldstone bosons exist; The fermion masses are generated by a ultraviolet-complete renormalizable extended technicolor sector with techni-GIM mechanism and hence the sector is safe from flavor-changing-neutral-current constraints; The ''e{sup +}e{sup -}'' production of techni-states in the superconformal window is calculable; The electroweak precision observables are (un)fortunately not calculable.
Date: July 27, 2003
Creator: Murayama, Hitoshi
System: The UNT Digital Library
Numerical simulation of a premixed turbulent V-flame (open access)

Numerical simulation of a premixed turbulent V-flame

We present three-dimensional, time-dependent simulations of a full-size laboratory-scale rod-stabilized premixed turbulent V-flame. The computations use an adaptive projection method based on a low Mach number formulation that incorporates detailed chemical kinetics and transport. The simulations are performed without introducing models for turbulence or turbulence chemistry interaction. We outline the numerical procedure and experimental setup, and compare computed results to mean flame location and surface wrinkling statistics gathered from experiment.
Date: July 27, 2003
Creator: Bell, John B.; Day, Marc S.; Grcar, Joseph F.; Lijewski, Michael J.; Johnson, Matt R.; Cheng, Robert K. et al.
System: The UNT Digital Library
Analysis of carbon chemistry in numerical simulations of vortex flame interaction (open access)

Analysis of carbon chemistry in numerical simulations of vortex flame interaction

In this paper we discuss the application of a new diagnostic tool for analysis of flame simulations. This methodology is based on following specific chemical elements, e.g., carbon or nitrogen, as they move through the system. From this perspective an ''atom'' is a component of a molecule that is being transported through the simulation domain by advection and diffusion. Reactions cause the atom to shift from one species to another with the subsequent transport of the atom determined by the movement of the new species.
Date: July 27, 2003
Creator: Bell, John B.; Day, Marcus S.; Grcar, Joseph F. & Lijewski, Michael J.
System: The UNT Digital Library
Laboratory evaluation of fan/filter units' aerodynamic and energy performance (open access)

Laboratory evaluation of fan/filter units' aerodynamic and energy performance

The paper discusses the benefits of having a consistent testing method to characterize aerodynamic and energy performance of FFUs. It presents evaluation methods of laboratory-measured performance of ten relatively new, 1220 mm x 610 mm (or 4 ft x 2 ft) fan-filter units (FFUs), and includes results of a set of relevant metrics such as energy performance indices (EPI) based upon the sample FFUs tested. This paper concludes that there are variations in FFUs' performance, and that using a consistent testing and evaluation method can generate compatible and comparable FFU performance information. The paper also suggests that benefits and opportunities exist for our method of testing FFU energy performance to be integrated in future recommended practices.
Date: July 27, 2004
Creator: Xu, Tengfang & Jeng, Ming-Shan
System: The UNT Digital Library
Uranium Age Determination by Measuring the 230Th / 234U Ratio (open access)

Uranium Age Determination by Measuring the 230Th / 234U Ratio

A radiochemical isotope dilution mass spectrometry method has been developed to determine the age of uranium materials. The amount of 230Th activity, the first progeny of 234U, that had grown into a small uranium metal sample was used to determine the elapsed time since the material was last radiochemically purified. To preserve the sample, only a small amount of oxidized uranium was removed from the surface of the sample and dissolved. Aliquots of the dissolved sample were spiked with 233U tracer and radiochemically purified by anion-exchange chromatography. The 234U isotopic concentration was then determined by thermal ionization mass spectrometry. Additional aliquots of the sample were spiked with 229Th tracer, and the thorium was purified using two sequential anion-exchange chromatography separations. The isotopic concentrations of 230Th and 232Th were determined by TIMS. The lack of any 232Th confirmed the assumption that all thorium was removed from the uranium sample at the time of purification. The 230Th and 234U mass concentrations were converted to activities and the 230Th/234U ratio for the sample was calculated. The experimental 230Th/234U ratio showed the uranium in this sample was radiochemically purified in about 1945. Isotope dilution thermal ionization mass spectrometry has sufficient sensitivity to determine the …
Date: July 27, 2004
Creator: LAMONT, STEPHENP.
System: The UNT Digital Library
Development of superconducting magnet systems for HIFExperiments (open access)

Development of superconducting magnet systems for HIFExperiments

The U.S. Heavy Ion Fusion program is developing superconducting focusing quadrupoles for near-term experiments and future driver accelerators. Following the fabrication and testing of several models, a baseline quadrupole design was selected and further optimized. The first prototype of the optimized design achieved a conductor-limited gradient of 132 T/m in a 70 mm bore, with measured field harmonics within 10 parts in 10{sup 4}. In parallel, a compact focusing doublet was fabricated and tested using two of the first-generation quadrupoles. After assembly in the cryostat, both magnets reached their conductor-limited quench current. Further optimization steps are currently underway to improve the performance of the magnet system and reduce its cost. They include the fabrication and testing of a new prototype quadrupole with reduced field errors as well as improvements of the cryostat design for the focusing doublet. The prototype units will be installed in the HCX beamline at LBNL, to perform accelerator physics experiments and gain operational experience. Successful results in the present phase will make superconducting magnets a viable option for the next generation of integrated beam experiments.
Date: July 27, 2004
Creator: Sabbi, Gian Luca; Faltens, A.; Leitzke, A.; Seidl, P.; Lund, S.; Martovets ky, N. et al.
System: The UNT Digital Library
Helium Release Behavior of Aged Titanium Tritides (open access)

Helium Release Behavior of Aged Titanium Tritides

One sample of bulk Ti has been loaded with a 50 per cent / 50 per cent deuterium/tritium mixture and statically aged for 6.5 years. Thermal desorption of the sample shows an initial release of hydrogen isotopes followed by 3He release. Subsequent D2 loading/desorption was used to quantify the trapped tritium heel. The sample shows an excess hydrogen capacity as a second thermal desorption peak that partially disappears and shifts with annealing at 923-973K. The main hydrogen desorption peak also shifts to higher temperature, indicating a partial reversal of the tritium-decay induced damage by annealing.
Date: July 27, 2004
Creator: SHANAHAN, KIRKL.
System: The UNT Digital Library
Systems analysis for modular versus multi-beam HIF drivers (open access)

Systems analysis for modular versus multi-beam HIF drivers

None
Date: July 27, 2004
Creator: Meier, W. R. & Logan, B. G.
System: The UNT Digital Library