Comparison of the present and planned operation of the SIS18 and the AGS Booster with intermediate charge state heavy ions (open access)

Comparison of the present and planned operation of the SIS18 and the AGS Booster with intermediate charge state heavy ions

N/A
Date: February 1, 2006
Creator: A., Smolyakov; Fischer, W.; Omet, C. & Spiller, P.
Object Type: Report
System: The UNT Digital Library
Fast Extraction from the Booster to R Line using Two Kicks from the F3 Kicker (open access)

Fast Extraction from the Booster to R Line using Two Kicks from the F3 Kicker

N/A
Date: February 1, 2006
Creator: K., Zeno
Object Type: Report
System: The UNT Digital Library
Electron Clouds in the Relativistic Heavy Ion Collider (open access)

Electron Clouds in the Relativistic Heavy Ion Collider

N/A
Date: February 1, 2006
Creator: I., Aziz U.
Object Type: Report
System: The UNT Digital Library
Contributions to the Genesis and Progress of ICF (open access)

Contributions to the Genesis and Progress of ICF

Inertial confinement fusion (ICF) has progressed from the detonation of large-scale fusion explosions initiated by atomic bombs in the early 1950s to final preparations for initiating small-scale fusion explosions with giant lasers. The next major step after ignition will be development of high performance targets that can be initiated with much smaller, lower cost lasers. In the 21st century and beyond, ICF's grand challenge is to develop practical power plants that generate low cost, clean, inexhaustible fusion energy. In this chapter, I first describe the origin in 1960-61 of ICF target concepts, early speculations on laser driven 'Thermonuclear Engines' for power production and rocket propulsion, and encouraging large-scale nuclear explosive experiments conducted in 1962. Next, I recall the 40-year, multi-billion dollar ignition campaign - to develop a matched combination of sufficiently high-performance implosion lasers and sufficiently stable targets capable of igniting small fusion explosions. I conclude with brief comments on the NIF ignition campaign and very high-performance targets, and speculations on ICF's potential in a centuries-long Darwinian competition of future energy systems. My perspectives in this chapter are those of a nuclear explosive designer, optimistic proponent of ICF energy, and Livermore Laboratory leader. The perspectives of Livermore's post 1970 laser …
Date: February 15, 2006
Creator: Nuckolls, J. H.
Object Type: Book
System: The UNT Digital Library
Initiation Pressure Thresholds from Three Sources (open access)

Initiation Pressure Thresholds from Three Sources

None
Date: February 27, 2006
Creator: Souers, P C & Vitello, P
Object Type: Article
System: The UNT Digital Library
WRN Exonuclease Structure, Molecular Mechanism, and DNA EndProcessing Role (open access)

WRN Exonuclease Structure, Molecular Mechanism, and DNA EndProcessing Role

WRN is unique among the five human RecQ DNA helicases by having a functional exonuclease domain (WRN-exo) and being defective in the premature aging and cancer-related disorder Werner syndrome. Here, we characterize WRN-exo crystal structures, biochemical activity and participation in DNA end-joining. Metal ion complex structures, active site mutations and activity assays reveal a two-metal-ion mediated nuclease mechanism. The DNA end-binding Ku70/80 complex specifically stimulates WRN-exo activity, and structure-based mutational inactivation of WRN-exo alters DNA end-joining in human cells. We furthermore establish structural and biochemical similarities of WRN-exo to DnaQ family replicative proofreading exonucleases, with WRN-specific adaptations consistent with dsDNA specificity and functionally important conformational changes. These results indicate WRN-exo is a human DnaQ family member and support analogous proof-reading activities that are stimulated by Ku70/80 with implications for WRN functions in age related pathologies and maintenance of genomic integrity.
Date: February 15, 2006
Creator: Perry, J. Jefferson P.; Yannone, Steven M.; Holden, Lauren G.; Hitomi, Chiharu; Asaithamby, Aroumougame; Han, Seungil et al.
Object Type: Article
System: The UNT Digital Library
Preliminary Assessment of Potential Impacts to Dungeness Crabs from Disposal of Dredged Materials from the Columbia River (open access)

Preliminary Assessment of Potential Impacts to Dungeness Crabs from Disposal of Dredged Materials from the Columbia River

Dredging of the Columbia River navigation channel has raised concerns about dredging-related impacts on Dungeness crabs (Cancer magister). The overall objectives of this effort are to synthesize what is known about disposal effects on Dungeness crabs (Phase 1) and to offer approaches to quantify the effects, including approaches to gain a population-level perspective on any effects found in subsequent studies (Phase 2). This report documents Phase 1, which included (1) development of a conceptual model to integrate knowledge about crab biology and the physical processes occurring during disposal, (2) application of physics-based numerical modeling of the disposal event to understand the physical forces and processes to which a crab might be exposed during disposal, (3) conduct of a vulnerability analysis to identify the potential mechanisms by which crabs may be injured, and (4) recommendations of topics and approaches for future studies to assess the potential population-level effects of disposal on Dungeness crabs. The conceptual model first recognizes that disposal of dredged materials is a physically dynamic process with three aspects: (1) convective descent and bottom encounter, (2) dynamic collapse and spreading, and (3) mounding. Numerical modeling was used to assess the magnitude of the potentially relevant forces and extent of …
Date: February 1, 2006
Creator: Pearson, Walter H.; Miller, Martin C.; Williams, Greg D.; Kohn, Nancy P. & Skalski, John R.
Object Type: Report
System: The UNT Digital Library
National Carbon Sequestration Database and Geographic Information System (NatCarb) (open access)

National Carbon Sequestration Database and Geographic Information System (NatCarb)

None
Date: February 21, 2006
Creator: Carr, Timothy R.
Object Type: Report
System: The UNT Digital Library
Characterization of Slag, Fly Ash and Portland Cement for Saltstone (open access)

Characterization of Slag, Fly Ash and Portland Cement for Saltstone

Batch-to-batch variability in the chemical and physical properties of the fly ash, slag and portland cement (binders) will be an ongoing concern over the many years that salt waste from Tank 50 will be processed into grout at the Saltstone Processing Facility. This batch-to-batch variability in the properties of the binder materials translates to variability in the fresh and cured properties of Saltstone. Therefore, it is important to quantify the batch-to-batch variability of the binder materials and the resultant variation in grout properties. This report is the starting point for that process by providing the baseline (reference point) binder properties to which future batches of binder materials can be compared. For this characterization effort, properties of fly ash, slag and portland cement were obtained and documented in this report. These properties included particle size distribution by laser light scattering and dry sieving, particle size and morphology by scanning electron microscopy, true, aerated and tapped densities, chemical composition, rheological properties of the water based slurries made from individual binder material, and volatility through thermogravimetric analysis and differential thermal analysis. The properties presented in this report also provide a baseline data set to assist in problem solving efforts when or if unanticipated …
Date: February 1, 2006
Creator: Harbour, J
Object Type: Report
System: The UNT Digital Library
Targeted Gene Deletion Demonstrates that Cell Adhesion MoleculeICAM-4 is Critical for Erythroblastic Island Formation (open access)

Targeted Gene Deletion Demonstrates that Cell Adhesion MoleculeICAM-4 is Critical for Erythroblastic Island Formation

Erythroid progenitors differentiate in erythroblastic islands, bone marrow niches composed of erythroblasts surrounding a central macrophage. Evidence suggests that within islands adhesive interactions regulate erythropoiesis and apoptosis. We are exploring whether erythroid intercellular adhesion molecule-4 (ICAM-4), animmunoglobulin superfamily member, participates in island formation. Earlier, we identified alpha V integrins as ICAM-4 counter receptors. Since macrophages express alpha V, ICAM-4 potentially mediates island attachments. To test this, we generated ICAM-4 knockout mice and developed quantitative, live cell techniques for harvesting intact islands and for reforming islands in vitro. We observed a 47 percent decrease in islands reconstituted from ICAM-4 null marrow compared to wild type. We also found a striking decrease in islands formed in vivo in knockout mice. Further, peptides that block ICAM-4 alpha V adhesion produced a 53-57 percent decrease in reconstituted islands, strongly suggesting that ICAM-4 binding to macrophage alpha V functions in island integrity. Importantly, we documented that alpha V integrin is expressed in macrophages isolated from erythro blastic islands. Collectively, these data provide convincing evidence that ICAM-4 is critical in erythroblastic island formation via ICAM-4/alpha V adhesion and also demonstrate that the novel experimental strategies we developed will be valuable in exploring molecular mechanisms of erythroblastic …
Date: February 15, 2006
Creator: Lee, Gloria; Lo, Annie; Short, Sarah A.; Mankelow, Tosti J.; Spring, Frances; Parsons, Stephen F. et al.
Object Type: Article
System: The UNT Digital Library
PAIRWISE BLENDING OF HIGH LEVEL WASTE (HLW) (open access)

PAIRWISE BLENDING OF HIGH LEVEL WASTE (HLW)

The primary objective of this study is to demonstrate a mission scenario that uses pairwise and incidental blending of high level waste (HLW) to reduce the total mass of HLW glass. Secondary objectives include understanding how recent refinements to the tank waste inventory and solubility assumptions affect the mass of HLW glass and how logistical constraints may affect the efficacy of HLW blending.
Date: February 22, 2006
Creator: CERTA, P.J.
Object Type: Report
System: The UNT Digital Library
Thermal Conductivity of Ordered Molecular Water (open access)

Thermal Conductivity of Ordered Molecular Water

We use molecular dynamics simulation to investigate thermal transport characteristics of water with various degree of orientational and translational order induced by the application of an electric field. We observe that orientational ordering of the water dipole moments has a minor effect on the thermal conductivity. However, electric-field induced crystallization and associated translational order results in approximately a 3-fold increase of thermal conductivity with respect to the base water, i.e., to values comparable with those characterizing ice crystal structures.
Date: February 16, 2006
Creator: Evans, W; Fish, J & Keblinski, P
Object Type: Report
System: The UNT Digital Library
International Symposium on Site Characterization for CO2Geological Storage (open access)

International Symposium on Site Characterization for CO2Geological Storage

Several technological options have been proposed to stabilize atmospheric concentrations of CO{sub 2}. One proposed remedy is to separate and capture CO{sub 2} from fossil-fuel power plants and other stationary industrial sources and to inject the CO{sub 2} into deep subsurface formations for long-term storage and sequestration. Characterization of geologic formations for sequestration of large quantities of CO{sub 2} needs to be carefully considered to ensure that sites are suitable for long-term storage and that there will be no adverse impacts to human health or the environment. The Intergovernmental Panel on Climate Change (IPCC) Special Report on Carbon Dioxide Capture and Storage (Final Draft, October 2005) states that ''Site characterization, selection and performance prediction are crucial for successful geological storage. Before selecting a site, the geological setting must be characterized to determine if the overlying cap rock will provide an effective seal, if there is a sufficiently voluminous and permeable storage formation, and whether any abandoned or active wells will compromise the integrity of the seal. Moreover, the availability of good site characterization data is critical for the reliability of models''. This International Symposium on Site Characterization for CO{sub 2} Geological Storage (CO2SC) addresses the particular issue of site characterization …
Date: February 23, 2006
Creator: Tsang, Chin-Fu
Object Type: Article
System: The UNT Digital Library
Quantum Well Thermoelectrics for Converting Waste Heat to Electricity Quarterly Technical Progress Report: October 2005 - January 2006 (open access)

Quantum Well Thermoelectrics for Converting Waste Heat to Electricity Quarterly Technical Progress Report: October 2005 - January 2006

New thermoelectric materials using Quantum Well (QW) technology are expected to increase the energy conversion efficiency to more than 25% from the present 5%, which will allow for the low cost conversion of waste heat into electricity. Hi-Z Technology, Inc. has been developing QW technology over the past six years. It will use Caterpillar, Inc., a leader in the manufacture of large scale industrial equipment, for verification and life testing of the QW films and modules. Other members of the team are Pacific Northwest National Laboratory, who will sputter large area QW films. The Scope of Work is to develop QW materials from their present proof-of-principle technology status to a pre-production level over a proposed three year period. This work will entail fabricating the QW films through a sputtering process of 50 {micro}m thick multi layered films and depositing them on 12 inch diameter, 5 {micro}m thick Si substrates. The goal in this project is to produce the technology for fabricating a basic 10-20 watt module that can be used to build up any size generator such as: a 5-10 kW Auxiliary Power Unit (APU), a multi kW Waste Heat Recovery Generator (WHRG) for a class 8 truck or as …
Date: February 1, 2006
Creator: Ghamaty, Saeid
Object Type: Report
System: The UNT Digital Library
Smoothing of ultrathin silver films by transition metalseeding (open access)

Smoothing of ultrathin silver films by transition metalseeding

The nucleation and coalescence of silver islands on coated glass was investigated by in-situ measurements of the sheet resistance. Sub-monolayer amounts of transition metals (Nb, Ti, Ni, Cr, Zr, Ta, and Mo) were deposited prior to the deposition of silver. It was found that some, but not all, of the transition metals lead to coalescence of silver at nominally thinner films with smoother topology. The smoothing effect of the transition metal at sub-monolayer thickness can be explained by a thermodynamic model of surface energies.
Date: February 10, 2006
Creator: Anders, Andre; Byon, Eungsun; Kim, Dong-Ho; Fukuda, Kentaro & Lim,Sunnie H.N.
Object Type: Article
System: The UNT Digital Library
Measuring the branching ratio of the rare decay pi0 --> e+ e- (open access)

Measuring the branching ratio of the rare decay pi0 --> e+ e-

A precise branching ratio measurement of the rare decay {pi}{sup 0} {yields} e{sup +}e{sup -} has been made. The measurement was made with the rare kaon decay experiment KTeV at Fermilab where the source of {pi}{sup 0}s was K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sup 0} decaying in flight. A total of 794 fully reconstructed K{sub L} {yields} 3{pi}{sup 0} events consistent with two of the intermediate {pi}{sup 0}s decaying into {gamma}{gamma} and one into e{sup +}e{sup -} were collected. An estimated 53.2 {+-} 11.0 of these events were expected to be background. Normalizing to the {pi}{sup 0} Dalitz decay they found Br({pi}{sup 0} {yields} e{sup +}e{sup -}, (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2} > 0.95) = (6.44 {+-} 0.25(stat) {+-} 0.22(syst)) x 10{sup -8} where internal radiation, {pi}{sup 0} {yields} e{sup +}e{sup -}({gamma}), was limited by the requirement (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2} > 0.95 which separated it from the tree level Dalitz decay, {pi}{sup 0} {yields} e{sup +}e{sup -}P{gamma}.
Date: February 1, 2006
Creator: Niclasen, Rune
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Using a Family of Dividing Surfaces Normal to the Minimum EnergyPath for Quantum Instanton Rate Constants (open access)

Using a Family of Dividing Surfaces Normal to the Minimum EnergyPath for Quantum Instanton Rate Constants

One of the outstanding issues in the quantum instanton (QI) theory (or any transition state-type theory) for thermal rate constants of chemical reactions is the choice of an appropriate ''dividing surface'' (DS) that separates reactants and products. (In the general version of the QI theory, there are actually two dividing surfaces involved.) This paper shows one simple and general way for choosing DS's for use in QI Theory, namely using the family of (hyper) planes normal to the minimum energy path (MEP) on the potential energy surface at various distances s along it. Here the reaction coordinate is not one of the dynamical coordinates of the system (which will in general be the Cartesian coordinates of the atoms), but rather simply a parameter which specifies the DS. It is also shown how this idea can be implemented for an N-atom system in 3d space in a way that preserves overall translational and rotational invariance. Numerical application to a simple system (the colliner H + H{sub 2} reaction) is presented to illustrate the procedure.
Date: February 22, 2006
Creator: Li, Yimin & Miller, Wlliam H.
Object Type: Article
System: The UNT Digital Library
Verification and Uncertainty Reduction of Amchitka Underground Nuclear Testing Models (open access)

Verification and Uncertainty Reduction of Amchitka Underground Nuclear Testing Models

The modeling of Amchitka underground nuclear tests conducted in 2002 is verified and uncertainty in model input parameters, as well as predictions, has been reduced using newly collected data obtained by the summer 2004 field expedition of CRESP. Newly collected data that pertain to the groundwater model include magnetotelluric (MT) surveys conducted on the island to determine the subsurface salinity and porosity structure of the subsurface, and bathymetric surveys to determine the bathymetric maps of the areas offshore from the Long Shot and Cannikin Sites. Analysis and interpretation of the MT data yielded information on the location of the transition zone, and porosity profiles showing porosity values decaying with depth. These new data sets are used to verify the original model in terms of model parameters, model structure, and model output verification. In addition, by using the new data along with the existing data (chemistry and head data), the uncertainty in model input and output is decreased by conditioning on all the available data. A Markov Chain Monte Carlo (MCMC) approach is adapted for developing new input parameter distributions conditioned on prior knowledge and new data. The MCMC approach is a form of Bayesian conditioning that is constructed in such …
Date: February 1, 2006
Creator: Hassan, Ahmed & Chapman, Jenny
Object Type: Report
System: The UNT Digital Library
Concept for lightweight spaced-based deposition technology (open access)

Concept for lightweight spaced-based deposition technology

In this contribution we will describe a technology path to very high quality coatings fabricated in the vacuum of space. To accomplish the ambitious goals set out in NASA's Lunar-Mars proposal, advanced thin-film deposition technology will be required. The ability to deposit thin-film coatings in the vacuum of lunar-space could be extremely valuable for executing this new space mission. Developing lightweight space-based deposition technology (goal:<300 g, including power supply) will enable the future fabrication and repair of flexible large-area space antennae and fixed telescope mirrors for lunar-station observatories. Filtered Cathodic Arc (FCA) is a proven terrestrial energetic thin-film deposition technology that does not need any processing gas but is well suited for ultra-high vacuum operation. Recently, miniaturized cathodic arcs have already been developed and considered for space propulsion. It is proposed to combine miniaturized pulsed FCA technology and robotics to create a robust, enabling space-based deposition system for the fabrication, improvement, and repair of thin films, especially of silver and aluminum, on telescope mirrors and eventually on large area flexible substrates. Using miniature power supplies with inductive storage, the typical low-voltage supply systems used in space are adequate. It is shown that high-value, small area coatings are within the reach …
Date: February 28, 2006
Creator: Fulton, Michael & Anders, Andre
Object Type: Article
System: The UNT Digital Library
Initial Demonstration of Mercury Wavefront Correction System (open access)

Initial Demonstration of Mercury Wavefront Correction System

High average power operation of the Mercury Laser induces dynamic aberrations to the laser beam wavefront. Analysis of recent data indicates that up to 4 waves of low order aberration (mainly focus error or power, with spatial resolution < 0.5 cm{sup -1}) could be expected at each pass. Because of the magnitude of the wavefront error, the logical position is to place a deformable mirror (DM) at the M11 position, where the DM will correct the beam between passes 1 & 2 and 3 & 4. Currently, there are only two established commercial vendors offering complete adaptive optic (AO) systems that can accommodate the Mercury beam size (45 x 75 mm) which are compatible with high damage threshold coatings. Xinetics (MA, USA) offers a complete AO system along with a Shack-Hartmann wavefront sensor. The Xinetics DM is based on lead magnesium niobate (PMN) technology. A number of US aerospace firms as well as NIF use Xinetics PMN technology for their DMs. Phasics (Paris, France) offers a complete AO solution with its proprietary SID-4, a four-way shearing interferometric wavefront sensor capable of high resolution (over 100 x 100 sampling points). The Phasics system includes a bimorph deformable mirror from Night-n-Opt (Moscow, …
Date: February 1, 2006
Creator: Liao, Z. M.
Object Type: Report
System: The UNT Digital Library
Gene expression signature in organized and growth arrested mammaryacini predicts good outcome in breast cancer (open access)

Gene expression signature in organized and growth arrested mammaryacini predicts good outcome in breast cancer

To understand how non-malignant human mammary epithelial cells (HMEC) transit from a disorganized proliferating to an organized growth arrested state, and to relate this process to the changes that occur in breast cancer, we studied gene expression changes in non-malignant HMEC grown in three-dimensional cultures, and in a previously published panel of microarray data for 295 breast cancer samples. We hypothesized that the gene expression pattern of organized and growth arrested mammary acini would share similarities with breast tumors with good prognoses. Using Affymetrix HG-U133A microarrays, we analyzed the expression of 22,283 gene transcripts in two HMEC cell lines, 184 (finite life span) and HMT3522 S1 (immortal non-malignant), on successive days post-seeding in a laminin-rich extracellular matrix assay. Both HMECs underwent growth arrest in G0/G1 and differentiated into polarized acini between days 5 and 7. We identified gene expression changes with the same temporal pattern in both lines. We show that genes that are significantly lower in the organized, growth arrested HMEC than in their proliferating counterparts can be used to classify breast cancer patients into poor and good prognosis groups with high accuracy. This study represents a novel unsupervised approach to identifying breast cancer markers that may be of …
Date: February 8, 2006
Creator: Fournier, Marcia V.; Martin, Katherine J.; Kenny, Paraic A.; Xhaja, Kris; Bosch, Irene; Yaswen, Paul et al.
Object Type: Article
System: The UNT Digital Library
Fiber Laser Replacement for Short Pulse Ti:Sapphire Oscillators -- Scalable Mode Locking to Record Pulse Energies (open access)

Fiber Laser Replacement for Short Pulse Ti:Sapphire Oscillators -- Scalable Mode Locking to Record Pulse Energies

We have investigated fiber-based lasers that mode-lock via three nonlinear mechanisms: pulse evolution, bend loss, and tunneling. Experiments with nonlinear pulse evolution proved especially promising; we report here a fiber laser that produces 25 nJ, sub-200 fs pulses, an energy that is 60% higher than previous reports. Experiments with nonlinear bend loss were inconclusive; though bend-loss data show that the effect exits, we were not able to use the phenomenon to lock a laser. New models suggest that nonlinear tunneling could provide an alternate path.
Date: February 14, 2006
Creator: Dawson, J W; Messerly, M J & An, J
Object Type: Report
System: The UNT Digital Library
DIGITAL RADIOGRAPHY OF SPECIAL NUCLEAR MATERIAL TEST PACKAGES (open access)

DIGITAL RADIOGRAPHY OF SPECIAL NUCLEAR MATERIAL TEST PACKAGES

The purpose of this document is to provide a brief introduction to digital radiography (DR), and a description of the DR configuration that was used to radiographically image the Special Nuclear Material (SNM) Test Packages before and after function tests that have been conducted. Also included are (1) Attachment 1, a comprehensive index that describes at which phase of the certification process that digital radiographic images were acquired, (2) digital radiographic images of each of the six packages at various stages of the certification process, and (3) Attachment 2, imaging instructions, that specify the setup procedures and detailed parameters of the DR imaging methodology that were used.
Date: February 2, 2006
Creator: HOWARD, BOYD
Object Type: Report
System: The UNT Digital Library
The 10,000 Year Plan (open access)

The 10,000 Year Plan

Pallavi Pharkya thinks a lot about the future. Pharkya, a Ph.D. candidate in materials science and engineering, works in the area of corrosion science, predicting how materials will perform over extended periods of time. Her particular focus is a nickel-chromium-molybdenum alloy called C-22, a highly corrosion-resistant metal. Pharkya's aim is to help determine whether containers made from C-22 can be used to store high-energy nuclear waste--for 10,000 years and longer. Pharkya's work is part of a plan by the U.S. Department of Energy to consolidate the country's nuclear waste in a single proposed repository. The proposed repository is in Yucca Mountain located in a remote Nevada desert. Currently about 70,000 metric tons of spent nuclear fuel and high-level radioactive waste are divided between approximately 100 sites around the country. The undertaking, Pharkya emphasizes, is massive. To study just the corrosion aspects of the packaging, Case is collaborating with eight other universities, five national labs and Atomic Energy of Canada Limited. Even with so many players, the study will likely take several years to complete. Heading the entire group is Joe Payer, a professor of materials science and engineering at Case and Pharkya's mentor. ''I came here to have the opportunity …
Date: February 10, 2006
Creator: Srisaro, L.
Object Type: Article
System: The UNT Digital Library