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Metabolic engineering of proanthocyanidins by ectopic expression of transcription factors in Arabidopsis thaliana (open access)

Metabolic engineering of proanthocyanidins by ectopic expression of transcription factors in Arabidopsis thaliana

Article on metabolic engineering of proanthocyanidins by ectopic expression of transcription factors in Arabidopsis thaliana.
Date: August 16, 2005
Creator: Sharma, Shashi B. & Dixon, R. A.
System: The UNT Digital Library
THE COLOR GLASS CONDENSATE: AN INTUITIVE DESCRIPTION. (open access)

THE COLOR GLASS CONDENSATE: AN INTUITIVE DESCRIPTION.

The author argues that the physics of the scattering of very high energy strongly interacting particles is controlled by a new, universal form of matter, the Color Glass Condensate. I motivate the existence of this matter and describe some of its properties.
Date: June 16, 2005
Creator: McLerran, L.
System: The UNT Digital Library
Highly Compressed Ion Beam for High Energy Density Science (open access)

Highly Compressed Ion Beam for High Energy Density Science

The Heavy Ion Fusion Virtual National Laboratory is developing the intense ion beams needed to drive matter to the High Energy Density regimes required for Inertial Fusion Energy and other applications. An interim goal is a facility for Warm Dense Matter studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach they are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target ''foils,'' which may in fact be foams with mean densities 1% to 10% of solid. This approach complements that being pursued at GSI Darmstadt, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrically target. They present the beam requirements for Warm Dense Matter experiments. The authors discuss neutralized drift compression and final focus experiments and modeling. They describe suitable accelerator architectures based on Drift-Tube Linac, RF, single-gap, Ionization-Front Accelerator, and Pulse-Line Ion Accelerator concepts. The last of these is being pursued experimentally. Finally, they discuss plans toward a user facility for target experiments.
Date: May 16, 2005
Creator: Friedman, A.; Barnard, J. J.; Briggs, R. J.; Callahan, D. A.; Caporaso, G. J.; Celata, C. M. et al.
System: The UNT Digital Library
2004 Mutagenesis Gordon Conference (open access)

2004 Mutagenesis Gordon Conference

Mutations are genetic alterations that drive biological evolution and cause many, if not all, human diseases. Mutation originates via two distinct mechanisms: ''vertical'' variation is de novo change of one or few bases, whereas ''horizontal'' variation occurs by genetic recombination, which creates new mosaics of pre-existing sequences. The Mutagenesis Conference has traditionally focused on the generation of mutagenic intermediates during normal DNA synthesis or in response to environmental insults, as well as the diverse repair mechanisms that prevent the fixation of such intermediates as permanent mutations. While the 2004 Conference will continue to focus on the molecular mechanisms of mutagenesis, there will be increased emphasis on the biological consequences of mutations, both in terms of evolutionary processes and in terms of human disease. The meeting will open with two historical accounts of mutation research that recapitulate the intellectual framework of this field and thereby place the current research paradigms into perspective. The two introductory keynote lectures will be followed by sessions on: (1) mutagenic systems, (2) hypermutable sequences, (3) mechanisms of mutation, (4) mutation avoidance systems, (5) mutation in human hereditary and infectious diseases, (6) mutation rates in evolution and genotype-phenotype relationships, (7) ecology, mutagenesis and the modeling of evolution …
Date: September 16, 2005
Creator: Jinks-Robertson, Dr. Sue
System: The UNT Digital Library
2004 Inorganic Chemistry Gordon Research Conference - July 18-23, 2004 (open access)

2004 Inorganic Chemistry Gordon Research Conference - July 18-23, 2004

The Gordon Research Conference (GRC) on 2004 Inorganic Chemistry Gordon Research Conference - July 18-23, 2004 was held at Salve Regina College, July 18-23, 2004. The Conference was well-attended with 110 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, 'free time' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.
Date: September 16, 2005
Creator: Clark, David
System: The UNT Digital Library
INITIAL TEST WELL CONDITIONING AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO (open access)

INITIAL TEST WELL CONDITIONING AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

None
Date: October 16, 2005
Creator: Oliver, R.D.; Dinsmoor, J.C.; Reyes-Cortes, I. & Aguilar, R. de la Garza
System: The UNT Digital Library
Zinc Treatment Effects on Corrosion Behavior of 304 Stainless Steel in High Temperature, Hydrogenated Water (open access)

Zinc Treatment Effects on Corrosion Behavior of 304 Stainless Steel in High Temperature, Hydrogenated Water

None
Date: August 16, 2005
Creator: Ziemniak, SE & Hanson, M
System: The UNT Digital Library
Inline Monitors for the SRS Small Column Ion Exchange Process (open access)

Inline Monitors for the SRS Small Column Ion Exchange Process

A Small Column Ion Exchange (SCIX) system, designed by the Oak Ridge and Savannah River National Laboratories (ORNL and SRNL), is a potential way to reduce Cs-137 concentrations in high-level radioactive waste at the Savannah River Site (SRS). SRNL has developed gamma-ray monitors for six locations within the SCIX system to verify the proper operation of the ion exchange system, detect cesium breakthrough, and confirm the presence of cesium before and after used resin is transferred to a grinder module. Two sodium iodide breakthrough monitors, one Geiger-Mueller breakthrough monitor, and three Geiger-Mueller transfer monitors were used. The present work provides a means of measuring the Cs-137 and Ba-137m breakthrough by taking multiple measurements in a process flow diversion and isolation loop. A lead shield was used for the NaI detectors, and the aperture of the collimator tube in this shield was designed using Monte Carlo analyses to provide the desired count rate for the gamma rays of interest. A computer program was written to collect data from the process monitors, provide alarm notification, and plot the data for ease of operation.
Date: May 16, 2005
Creator: Vito, Casella
System: The UNT Digital Library
Terascale Beam-Beam Simulations for Tevatron, RHIC and LHC (open access)

Terascale Beam-Beam Simulations for Tevatron, RHIC and LHC

In this paper, we report on recent advances in terascale simulations of the beam-beam interaction in Tevatron, RHIC and LHC.Computational methods for self consistent calculation of beam-beam forces are reviewed. New method for solving the two-dimensional Poisson equation with open boundary conditions is proposed and tested. This new spectral-finite difference method is a factor of four faster than the widely used FFT based Green function method for beam-beam interaction on axis. We also present applications to the study of antiproton losses during the injection stage at Tevatron, to the study of multiple bunch coherent beam-beam modes at RHIC, and to the study of beam-beam driven emittance growth at LHC.
Date: May 16, 2005
Creator: Qiang, J.
System: The UNT Digital Library
A 3d Parallel Beam Dynamics Code for Modeling High BrightnessBeams in Photoinjectors (open access)

A 3d Parallel Beam Dynamics Code for Modeling High BrightnessBeams in Photoinjectors

In this paper we report on IMPACT-T, a 3D beam dynamics code for modeling high brightness beams in photoinjectors and rf linacs. IMPACT-T is one of the few codes used in the photoinjector community that has a parallel implementation, making it very useful for high statistics simulations of beam halos and beam diagnostics. It has a comprehensive set of beamline elements, and furthermore allows arbitrary overlap of their fields. It is unique in its use of space-charge solvers based on an integrated Green function to efficiently and accurately treat beams with large aspect ratio, and a shifted Green function to efficiently treat image charge effects of a cathode. It is also unique in its inclusion of energy binning in the space-charge calculation to model beams with large energy spread. Together, all these features make IMPACT-T a powerful and versatile tool for modeling beams in photoinjectors and other systems. In this paper we describe the code features and present results of IMPACT-T simulations of the LCLS photoinjectors. We also include a comparison of IMPACT-T and PARMELA results.
Date: May 16, 2005
Creator: Qiang, J.; Lidia, S.; Ryne, R. & Limborg, C.
System: The UNT Digital Library
RF Design and Operating Performance of the Bnl/Aes 1.3 Ghz Single Cell Superconducting Rf Photocathode Electron Gun. (open access)

RF Design and Operating Performance of the Bnl/Aes 1.3 Ghz Single Cell Superconducting Rf Photocathode Electron Gun.

Over the past several years Advanced Energy Systems and BNL have been collaborating on the development and testing of a fully superconducting photocathode electron gun. Over the past year we have begun to realize significant results which have been published elsewhere [1]. This paper will review the RF design of the gun under test and present results of its performance under various operating conditions. Results for cavity quality factor will be presented for various operating temperatures and cavity field gradients. We will also discuss future plans for testing using this gun.
Date: May 16, 2005
Creator: Cole, M.; Kneisel, P.; Ben-Zvi, Ilan; Burrill, A.; Hahn, G.; Rao, T. et al.
System: The UNT Digital Library
State-of-the-Art Electron Guns and Injector Designs for Energy Recovery Linacs (Erl) (open access)

State-of-the-Art Electron Guns and Injector Designs for Energy Recovery Linacs (Erl)

A key technology issue of energy recovery linac (ERL) devices for high-power free-electron laser (FEL) and fourth generation light sources is the demonstration of reliable, high-brightness, high-power injector operation. Three ongoing programs that target up to 0.5 Ampere photocathode injector performance with required EFU brightness, are described. The first is a DC gun and superconducting RF (SRF) booster cryomodule. Such a 748.5 MHz device is being assembled and will be tested up to 100 mA at the Thomas Jefferson National Accelerator Facility (JLAB) beginning in 2006. The second approach is a high-current normal-conducting RF (NCRF) injector. A 700 MHz gun will undergo thermal test in late 2005 at the Los Alamos National Laboratory (LANL), which when equipped with a suitable cathode, would be capable of exceeding 0.5 Ampere operation. Finally, a half-cell 703.75 MHz SRF gun with a diamond amplifier and other cathodes, will be tested to 0.5 Ampere at the Brookhaven National Laboratory (BNL) in 2007. The status and projected performance for each of these injector projects is presented.
Date: May 16, 2005
Creator: Todd, A. M. M.; Ambrosio, A.; Bluem, H.; Christina, V.; Cole, M. D.; Falletta, M. et al.
System: The UNT Digital Library
A Parallel 3d Model for The Multi-Species Low Energy BeamTransport System of the RIA Prototype ECR Ion Source Venus (open access)

A Parallel 3d Model for The Multi-Species Low Energy BeamTransport System of the RIA Prototype ECR Ion Source Venus

The driver linac of the proposed Rare Isotope Accelerator (RIA) requires a great variety of high intensity, high charge state ion beams. In order to design and to optimize the low energy beamline optics of the RIA front end,we have developed a new parallel three-dimensional model to simulate the low energy, multi-species ion beam formation and transport from the ECR ion source extraction region to the focal plane of the analyzing magnet. A multisection overlapped computational domain has been used to break the original transport system into a number of each subsystem, macro-particle tracking is used to obtain the charge density distribution in this subdomain. The three-dimensional Poisson equation is solved within the subdomain and particle tracking is repeated until the solution converges. Two new Poisson solvers based on a combination of the spectral method and the multigrid method have been developed to solve the Poisson equation in cylindrical coordinates for the beam extraction region and in the Frenet-Serret coordinates for the bending magnet region. Some test examples and initial applications will also be presented.
Date: May 16, 2005
Creator: Qiang, J.; Leitner, D. & Todd, D.
System: The UNT Digital Library
Optimizing connected component labeling algorithms (open access)

Optimizing connected component labeling algorithms

This paper presents two new strategies that can be used to greatly improve the speed of connected component labeling algorithms. To assign a label to a new object, most connected component labeling algorithms use a scanning step that examines some of its neighbors. The first strategy exploits the dependencies among them to reduce the number of neighbors examined. When considering 8-connected components in a 2D image, this can reduce the number of neighbors examined from four to one in many cases. The second strategy uses an array to store the equivalence information among the labels. This replaces the pointer based rooted trees used to store the same equivalence information. It reduces the memory required and also produces consecutive final labels. Using an array instead of the pointer based rooted trees speeds up the connected component labeling algorithms by a factor of 5 {approx} 100 in our tests on random binary images.
Date: January 16, 2005
Creator: Wu, Kesheng; Otoo, Ekow & Shoshani, Arie
System: The UNT Digital Library
Galactic Bulge Microlensing Events from the MACHO Collaboration (open access)

Galactic Bulge Microlensing Events from the MACHO Collaboration

The authors present a catalog of 450 relatively high signal-to-noise microlensing events observed by the MACHO collaboration between 1993 and 1999. The events are distributed throughout the fields and, as expected, they show clear concentration toward the Galactic center. No optical depth is given for this sample since no blending efficiency calculation has been performed, and they find evidence for substantial blending. In a companion paper they give optical depths for the sub-sample of events on clump giant source stars, where blending is a less significant effect. Several events with sources that may belong to the Sagittarius dwarf galaxy are identified. For these events even relatively low dispersion spectra could suffice to classify these events as either consistent with Sagittarius membership or as non-Sagittarius sources. Several unusual events, such as microlensing of periodic variable source stars, binary lens events, and an event showing extended source effects are identified. They also identify a number of contaminating background events as cataclysmic variable stars.
Date: June 16, 2005
Creator: Thomas, C. L.; Griest, K.; Popowski, P.; Cook, K. H.; Drake, A. J.; Minniti, D. et al.
System: The UNT Digital Library
Multi-Stage Bunch Compressors for the International LinearCollider (open access)

Multi-Stage Bunch Compressors for the International LinearCollider

We present bunch compressor designs for theInternationalLinear Collider (ILC) which achieve a reduction in RMS bunch length from6 mm to 0.3 mm via multiple stages of compression, with stages ofacceleration inserted between the stages of compression. The keyadvantage of multi-stage compression is that the maximum RMS energyspread is reduced to approximately 1 percent, compared to over 3 percentfor a single-stage design. Analytic and simulation studies of themulti-stage bunch compressors are presented, along with performancecomparisons to a single-stage system. Parameters for extending thesystems to a larger total compression factor are discussed.
Date: May 16, 2005
Creator: Tenenbaum, Peter G.; Raubenheimer, Tor O. & Wolski, Andrzej
System: The UNT Digital Library
COMPUTATIONAL MODELING OF CREVICE CORROSION STABILITY OF WETTED SS316L (open access)

COMPUTATIONAL MODELING OF CREVICE CORROSION STABILITY OF WETTED SS316L

None
Date: October 16, 2005
Creator: F. Cui, J. Presuel-Moreno, R. G. Kelly
System: The UNT Digital Library
Fourier Transform Infrared Spectroscopic Analysis Of Plastic Capsule Materials Exposed To Deuterium-Tritium (DT) Gas (open access)

Fourier Transform Infrared Spectroscopic Analysis Of Plastic Capsule Materials Exposed To Deuterium-Tritium (DT) Gas

Planar samples of varying thicknesses of both CH and CD glow discharge polymer have been measured with Fourier transform infrared (FTIR) spectroscopy before and after exposure to deuterium-tritium (DT) gas at elevated temperature and pressure. Planar samples of polyimide films made from both hydrogenated and deuterated precursors have also been examined by FTIR before and after DT exposure. The post-exposure FTIR spectra demonstrated no measurable exchange of hydrogen with deuterium or tritium for either polymer. Evidence for oxidation of the glow discharge polymer due to atmospheric oxygen was the only chemical change indicated by the FTIR data.
Date: June 16, 2005
Creator: Schoonover, J R; Steckle, Jr., W P; Elliot, N; Ebey, P S; Nobile, A; Nikroo, A et al.
System: The UNT Digital Library
General Relativity&Compact Stars (open access)

General Relativity&Compact Stars

Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10{sup …
Date: August 16, 2005
Creator: Glendenning, Norman K.
System: The UNT Digital Library
Effects of Microbial and Phosphate Amendments on the Bioavailability of Lead (Pb) in Shooting Range Soil (open access)

Effects of Microbial and Phosphate Amendments on the Bioavailability of Lead (Pb) in Shooting Range Soil

Heavy metals including lead (Pb) are released continually into the environment as a result of industrial, recreational, and military activities. Lead ranked number two on the CERCLA Priority List of Hazardous Substances and was identified as a major hazardous chemical found on 47% of USEPA's National Priorities List sites (Hettiarachchi and Pierzynski 2004). In-situ remediation of lead (Pb) contaminated soils may be accomplished by changing the soil chemistry and structure with the application of microbial and phosphate amendments. Soil contaminated with lead bullets was collected from the surface of the berm at Savannah River Site (SRS) Small Arms Training Academy (SATA) in Aiken, SC. While uncontaminated soils typically have Pb levels ranging from 2 to 200 mg/kg (Berti et al. 1998), previous analysis show Pb levels of the SATA berm to reach 8,673 mg/kg. Biosurfactants are surface-active compounds naturally produced by soil bacteria that can bind metals. Biosurfactants have a wide variety of chemical structures that reduce interfacial surface tensions (Jennings and Tanner 2000) and have demonstrated efficient metal complexion (Lin 1996). Biosurfactants also have the potential to change the availability of natural organic matter (Strong-Gunderson 1995). Two types of bacteria, Alcaligenes piechaudii and Pseudomonas putida, were employed as amendments …
Date: June 16, 2005
Creator: Brigmon, Robin; Wilson, Christina; Knox, Anna; Seaman, John & Smith, Garriet
System: The UNT Digital Library
Dynamical Effects Due to Fringe Field of the Magnets in Circular Accelerators (open access)

Dynamical Effects Due to Fringe Field of the Magnets in Circular Accelerators

The leading Lie generators, including the chromatic effects, due to hard-edge fringe field of single multipole and solenoid are derived from the vector potentials within a Hamiltonian system. These nonlinear generators are applied to the interaction region of PEP-II to analyze the linear errors due to the feed-down from the off-centered quadrupoles and solenoid. The nonlinear effects of tune shifts at large amplitude, the synchro-betatron sidebands near half integer and their impacts on the dynamic aperture are studied in the paper.
Date: May 16, 2005
Creator: Cai, Y. & Nosochkov, Yu
System: The UNT Digital Library
A Design Library of Magnet Support - a Proposal - (open access)

A Design Library of Magnet Support - a Proposal -

Although the ideal and universal support system has not been invented yet, there are many implementations which fulfill most of alignment's requirements. However, inventing a new support system seems to represent the last design challenge, why would we otherwise witness so many new attempts. Already Plato reminded his scholars that one should learn from the past. Unfortunately, learning from previous designs and implementations doesn't seem to carry much attraction. Or it is that we, the customers, are not doing our job by letting the design engineer know what we would like to see done, what we think works, and what is already there. This contribution is an initiative to create a reference for support systems which exist in our laboratories and we know do work. Such an undertaking will require everybody's active support and feedback. I already have to thank my peers at many laboratories who helped me put together this first draft. Only if a more or less complete library of existing designs can be compiled with easy access to drawings can we then hope that the support system design competition looses its challenge. As alignment tolerances get ever tighter, the interplay of alignment with mechanical engineering becomes ever …
Date: August 16, 2005
Creator: Ruland, Robert E.
System: The UNT Digital Library
Simulations and Experiments of Beam-Beam Effects in e+e- Storage Rings (open access)

Simulations and Experiments of Beam-Beam Effects in e+e- Storage Rings

Over the past decade, extensive simulations of beam-beam effects in e{sup +}e{sup -} colliders, based on the particle-in-cell method, were developed to explain many complex experimental observations. Recently, such simulations were used to predict the future luminosity performance of e{sup +}e{sup -} colliders. Some predictions have been proven to be correct in the existing accelerators. In this paper, many effects such as the beam-beam limit, crossing angle, parasitic collisions, betatron spectrum, and the beam-beam lifetime, will be directly compared between simulations and experiments.
Date: May 16, 2005
Creator: Cai, Y.; Seeman, J.; Kozanecki, W.; Ohmi, K. & Tawada, M.
System: The UNT Digital Library
Design of Ilc Extraction Line for 20 Mrad Crossing Angle (open access)

Design of Ilc Extraction Line for 20 Mrad Crossing Angle

One of the two ILC Interaction Regions will have a large horizontal crossing angle which would allow to extract the spent beams in a separate beam line. In this paper, the extraction line design for 20 mrad crossing angle is presented. This beam line transports the primary e{sup +}/e{sup -} and beamstrahlung photon beams from the IP to a common dump, and includes diagnostic section for energy and polarization measurements. The optics is designed for a large energy acceptance to minimize losses in the low energy tail of the disrupted beam. The extraction optics, diagnostic instrumentation and particle tracking simulations are described.
Date: May 16, 2005
Creator: Nosochkov, Y.; Moffeit, K.; Seryi, A.; Woods, M.; Arnold, R.; Oliver, W. et al.
System: The UNT Digital Library