Micromechanical characterization tools for highly-filled polymers (open access)

Micromechanical characterization tools for highly-filled polymers

We are attempting to characterize and model the micromechanical response of highly-filled polymers. In this class of materials, the continuous plastic binder used to bond the highly-filled material dominates the observed viscoelastic response. As a result, realistic lifetime analysis of these materials will require a thorough understanding of the contribution of the plastic binder. Laboratory applications of these materials include plastic bonded explosives, propellants, a variety of specialized filled organic materials for stockpile systems, and highly filled epoxy dielectric materials for the National Ignition Facility. We have explored numerous techniques to characterize the local microstructure of plastic bonded explosives. However, insufficient funding was obtained to bring these technologies to maturity, nevertheless our present tool set is significantly better than 2 years ago. We have also made some progress in developing an appropriate micromechanical constitutive modeling framework, based on a finite element method incorporating a cohesive zone model to represent the binder contribution within a Voronoi tesselation mesh structure for the PBX grains. A second modeling approach was used to incorporate analytical micromechanics (generalized self-consistent schemes). However, preliminary theoretical analysis strongly suggested that this approach would be invalid for such extremely high-filled systems like PBX.
Date: February 16, 2000
Creator: Groves, S; DeTeresa, S; Cunningham, B; Ciarlo, D; Allen, D; Clayton, K et al.
Object Type: Report
System: The UNT Digital Library
High-Energy Neutron Imaging Development at LLNL (open access)

High-Energy Neutron Imaging Development at LLNL

We are proceeding with the development of a high-energy (10 MeV) neutron imaging system for use as an inspection tool in nuclear stockpile stewardship applications. Our goal is to develop and deploy an imaging system capable of detecting cubic-mm-scale voids, cracks or other significant structural defects in heavily-shielded low-Z materials within nuclear device components. The final production-line system will be relatively compact (suitable for use in existing facilities within the DOE complex) and capable of acquiring both radiographic and tomographic (CT) images. In this report, we will review our recent programmatic accomplishments, focusing primarily on progress made in FY04. The design status of the high-intensity, accelerator-driven neutron source and large-format imaging detector associated with the system will be discussed and results from a recent high-energy neutron imaging experiment conducted at the Ohio University Accelerator Laboratory (OUAL) will also be presented.
Date: February 16, 2005
Creator: Hall, J. M.; Rusnak, B. & Shen, S.
Object Type: Report
System: The UNT Digital Library
XWRAPComposer: A Multi-Page Data Extraction Service for Bio-Computing Applications (open access)

XWRAPComposer: A Multi-Page Data Extraction Service for Bio-Computing Applications

This paper presents a service-oriented framework for the development of wrapper code generators, including the methodology of designing an effective wrapper program construction facility and a concrete implementation, called XWRAPComposer Three unique features distinguish XWRAPComposer from existing wrapper development approaches. First, XWRAPComposer is designed to enable multi-stage and multi-page data extraction. Second, XWRAPComposer is the only wrapper generation system that promotes the distinction of information extraction logic from query-answer control logic, allowing higher level of robustness against changes in the service provider's web site design or infrastructure. Third, XWRAPComposer provides a user-friendly plug-and-play interface, allowing seamless incorporation of external services and continuous changing service interfaces and data format.
Date: February 16, 2005
Creator: Liu, L.; Zhang, J.; Han, W.; Pu, C.; Caverlee, J.; Park, S. et al.
Object Type: Article
System: The UNT Digital Library
Diode-Pumped Alkali Atom Lasers 03-LW-024 Final Report (open access)

Diode-Pumped Alkali Atom Lasers 03-LW-024 Final Report

The recent work at LLNL on alkali-atom lasers has been remarkably successful and productive. Three main phases (so far) can be identified. First, the concept and demonstration of red lasers using (Ti:sapphire pumping) took place; during this time, Rubidium and Cesium resonance-line lasers were tested, and theoretical models were developed and shown to describe experimental results very reliably. Work done during this first phase has been well documented, and the models from that period are still in use for their predictions and for designing power-scaled lasers. [1 - 3] Second, attempts were made to produce a blue alkali-vapor laser using sequentially-resonant two-step pumping (again, using Ti:sapphire lasers.) Although a blue laser did not result, the physical limitations of our approach are now better-defined. Third, diode-pumped operation of a red laser (Rubidium) was attempted, and we eventually succeeded in demonstrating the world's first diode-pumped gas laser. [4] Because we have a defensible concept for producing an efficient, compact, lightweight, power-scaled laser (tens of kW,) we are in a position to secure outside funding, and would like to find a sponsor. For descriptions of work done during the ''first phase,'' see References [1 - 3] ''Phase two'' work is briefly described in …
Date: February 16, 2005
Creator: Page, R H & Beach, R J
Object Type: Report
System: The UNT Digital Library
A Strategic Initiative in Applied Biological Simulations 01-SI-012 Final Report for FY01 - FY03 (open access)

A Strategic Initiative in Applied Biological Simulations 01-SI-012 Final Report for FY01 - FY03

The goal of this Strategic Initiative in Applied Computational Biology has been to apply LLNL's expertise in computational simulation to forge a new laboratory core competency in biological simulation. By every measure, this SI has been very successful in this goal. Based on a strong publication record and large number of conference presentations and invited talks, we have built a recognized niche for LLNL in the burgeoning field of computational biology. Further, many of the projects that were previously part of this LDRD are now externally funded based on the research results and expertise developed under this SI. We have created successful collaborations with a number of outside research groups including several joint projects with the new UC Davis/LLNL Comprehensive Cancer Center. In addition to these scientific collaborations, the staff developed on this SI is involved in computational biology program development and advisory roles with other DOE laboratories and DOE Headquarters. Moreover, a number of capabilities and expertise created by this SI are finding use in LLNL programmatic applications. Finally, and most importantly, this SI project has brought to LLNL the human talent on who will be the ensuring the further success of computational biology at this laboratory.
Date: February 16, 2004
Creator: Lau, E. Y.; Venclovas, C.; Schwegler, E.; Gygi, F.; Colvin, M. E.; Bennion, B. J. et al.
Object Type: Report
System: The UNT Digital Library
Lasershot(sm) marking system: high-volume labeling for safety-critical parts (open access)

Lasershot(sm) marking system: high-volume labeling for safety-critical parts

The Lasershot Marking System uses laser pulses to safely and permanently impress identification markings on metal components. This process does not remove material or change surface chemistry and actually increases the marked area's resistance to fatigue and corrosion failure. Lasershot marking is ideally suited for marking parts used in situations where safety is critical--from hip-joint replacements to commercial airliner components. The minimum size of the mark is limited only by the resolution of the reading system, allowing manufacturers to mark parts which, up to now, have been too small to label with mechanical peening techniques. The high resolution of the Lasershot marks makes them difficult to reproduce, providing a solution to the ongoing problem of inferior, counterfeited parts. The high marking rate of up to six marks per second makes this system practical and cost-effective for marking high-volume components.
Date: February 16, 2001
Creator: Dane, C. B.; Hackel, L.; Honig, J.; Halpin, J.; Chen, H. L.; Mendieta, F. et al.
Object Type: Report
System: The UNT Digital Library
DynTG: A tool for Interactive, Dynamic Instrumentation (open access)

DynTG: A tool for Interactive, Dynamic Instrumentation

With the increasing complexity of today's systems, detailed performance analysis is more important than ever. We have developed DynTG, a tool for interactive, dynamic instrumentation. It uses performance module plugins to reconfigure the data acquisition and provides a source browser that allows users to insert any probe functionality provided by the modules dynamically into the target application. Any instrumentation can be added both before and during the application's execution and the acquired data is presented in realtime within the source viewer. This enables users to monitor their applications' progress and interactively control and adapt the instrumentation based on their observations.
Date: February 16, 2005
Creator: Schulz, M; May, J & Gyllenhaal, J
Object Type: Article
System: The UNT Digital Library
Semi-Continuous Measurements of Aerosol Chemical Composition During the Summer 2002 Yosemite National Park Special Study (open access)

Semi-Continuous Measurements of Aerosol Chemical Composition During the Summer 2002 Yosemite National Park Special Study

Semi-continuous measurements of fine particle composition were made over a period of several weeks in summer 2002 in Yosemite National Park, California. These included measurement of aerosol ionic composition (by PILS- Particle-Into-Liquid System) and aerosol carbon (by dual wavelength aethalometer and an R&P particulate carbon monitor). The data reveal that aerosol composition at the site is highly :variable in time, with a strong diurnal cycle. Interestingly, however, different diurnal cycles were sometimes observed for different chemical constituents of the particles. Organic carbon was observed to dominate fine particle mass, with some periods apparently associated with influx of smoke from wildfires in the western U.S. Measurements of fine particle carbon isotopes revealed the fraction of carbon from biogenic sources to range from approximately 73 to 95%. The ionic fraction of the aerosol was usually dominated by ammoniated sulfate. During most periods, PM{sub 2.5} nitrate was found primarily in sea salt particles from which chloride had been displaced. Strong variations in the extent of ammonia neutralization of sulfate were also observed. The ability to observe rapid changes in aerosol composition using these semi-continuous aerosol composition measurements is helpful for understanding the dynamic chemical composition of fine particles responsible for regional haze.
Date: February 16, 2003
Creator: Collette, J.; Lee, T.; Heath, J.; Carrico, C.; Herckes, P.; Engling, G. et al.
Object Type: Article
System: The UNT Digital Library
Organic Analysis of C-104 Tank Waste (open access)

Organic Analysis of C-104 Tank Waste

Fourteen jars of waste material from Tank C-104 were received by PNNL. The contents of all jars were mixed to provide a single composite. Each composite was homogenized and representative sub-samples extracted for organic, radiochemical, and inorganic regulatory analyses. The representative sub-samples were analyzed for inorganic, radiochemical, and organic analyses for analytes of interest as defined in Test Plan BNFL-29953-30, Rev. 1. This report presents the organic results. The inorganic and radiochemical results are reported in report WTP RPT-007, PNNL-13364 (formerly BNFL RPT 043).
Date: February 16, 2001
Creator: Evans, John C.; Campbell, James A.; Hoopes, Francis V.; Hoppe, Eric W.; Klinger, George S.; Mong, Gary M. et al.
Object Type: Report
System: The UNT Digital Library
Convective Transport in Tokamaks (open access)

Convective Transport in Tokamaks

Scrape-off-layer (SOL) convection in fusion experiments appears to be a universal phenomenon that can ''short-circuit'' the divertor in some cases. The theory of ''blob'' transport provides a simple and robust physical paradigm for studying convective transport. This paper summarizes recent advances in the theory of blob transport and its comparison with 2D and 3D computer simulations. We also discuss the common physical basis relating radial transport of blobs, pellets, and ELMs and a new blob regime that may lead to a connection between blob transport and the density limit.
Date: February 16, 2005
Creator: D'Ippolito, D. A.; Myra, J. R.; Russell, D. A.; Krasheninnikov, S. I.; Pigarov, A. Y.; Yu, G. Q. et al.
Object Type: Article
System: The UNT Digital Library
Single Cell Proteomics with Ultra-High Sensitivity Mass Spectrometry (open access)

Single Cell Proteomics with Ultra-High Sensitivity Mass Spectrometry

This project was a joint LDRD project between PAT, CMS and NAI with the objective to develop an instrument that analyzes the biochemical composition of single cells in real-time using bioaerosol mass spectrometry (BAMS) combined with advanced laser desorption and ionization techniques. Applications include both biological defense, fundamental cell biology and biomedical research. BAMS analyzes the biochemical composition of single, micrometer-sized particles (such as bacterial cells or spores) that can be directly sampled from air or a suspension. BAMS is based on an earlier development of aerosol time of flight mass spectrometry (ATOFMS) by members of our collaboration [1,2]. Briefly, in ATOFMS and BAMS aerosol particles are sucked directly from the atmosphere into vacuum through a series of small orifices. As the particles approach the ion source region of the mass spectrometer, they cross and scatter light from two CW laser beams separated by a known distance. The timing of the two bursts of scattered light created by each ''tracked'' particle reveals the speed, location and size of the particle. This information then enables the firing of a high-intensity laser such that the resulting laser pulse desorbs and ionizes molecules from the tracked particle just as it reaches the center …
Date: February 16, 2005
Creator: Frank, M
Object Type: Report
System: The UNT Digital Library
Hydrogen Storage in Carbon Nanotubes at High Pressures LDRD Final Report 03-ERD-047 (open access)

Hydrogen Storage in Carbon Nanotubes at High Pressures LDRD Final Report 03-ERD-047

This goal of this project was to perform feasibility experiments and measurements of the fundamental interactions between hydrogen and single wall carbon nanotubes (SWNT) at high pressures. High-pressure is an adjustable experimental parameter for tuning interaction strengths, thereby elucidating and providing insights into the fundamental nature of the H{sub 2}/SWNT system. We have developed and utilized systems and methodologies to make x-ray scattering, optical spectroscopic and electrical transport measurements. These activities have been productive in demonstrating capabilities and measuring properties of SWNTs under high-pressure conditions. We have also developed strong cooperative and complementary relationships with academic research colleagues at Stanford University. Building on these results and relationships, we hope to continue and expand our research as co-investigators in a joint Harvard-LLNL-Stanford proposal to the DOE ''Grand Challenge'' for Basic and Applied Research in Hydrogen Storage (Solicitation No. DE-PS36-03GO93013). Hydrogen storage is an active research topic with important basic science implications and a crucial enabling technology for advanced energy systems. Measurements of the H{sub 2} storage capacity indicate that it may achieve or exceed the storage capacity level (6.5 wt-%) mandated by the DOE hydrogen plan for fielding a hydrogen-fueled vehicle. The H{sub 2}/SWNT system has been the subject of intensive …
Date: February 16, 2004
Creator: Evans, W. J. & Cynn, H.
Object Type: Report
System: The UNT Digital Library
Automated approach for the identification of functionally-relevant small molecule inhibitors (open access)

Automated approach for the identification of functionally-relevant small molecule inhibitors

Radiation induces the formation of DNA damages via direct ionization or through the production of reactive oxygen intermediates that chemically modify DNA. Radiation is thought to elicit its cytotoxicity by inducing the formation of lethal DNA damage, including modified bases, baseless sites and strand breaks. To avert the deleterious effects of radiation and chromosomal modifications, cells are equipped with DNA repair systems and cellular responses that function to amend genetic imperfections and to prevent the replication of damaged DNA. The focus of this proposal is to develop a novel, function-based technology for isolating inhibitors of proteins involved in radiation-protection. Such inhibitor molecules represent potential radiosensitizing agents, which could be used to increase the biological effectiveness of a given radiation dose in anti-cancer treatment schemes. This project combines unique laboratory expertise in robotics, computational modeling, combinatorial chemistry, and DNA repair enzymology from the Biology & Biotechnology Research Program and the Chemistry and Material Science Directorate. The screening technique will utilize a simple flow-based filter system operated by robotics. Commercial laboratory instrumentation and automation are available for creating a nearly hands-off system for inhibitor molecule screening. Specifically, a general purpose dispensing instrument (i.e. the Packard Multiprobe II), using opaque, filter-backed microtiter plates, …
Date: February 16, 2000
Creator: Wilson, D. M., III
Object Type: Report
System: The UNT Digital Library
Functional characterization of dna repair proteins (open access)

Functional characterization of dna repair proteins

Genetic material (DNA) is susceptible to spontaneous decomposition, to attack by reactive chemicals produced naturally in cells, and to assault by environmental and food mutagens. DNA modifications can lead to permanent genetic changes that promote human disease. To combat the deleterious effects of DNA damage, organisms are equipped with DNA repair systems. The focus of our investigations has been to elucidate the details of mammalian DNA repair. These studies have provided important insights into the relationship of DNA repair to human disease and the genetic factors that contribute to individual susceptibility to the harmful effects of environmental mutagens (e.g. ionizing radiation), and have established a framework for designing more effective anti-cancer treatment schemes. To investigate questions related to DNA repair, its mechanism(s) and linkage to disease development, the authors are employing an array of molecular, cellular, biochemical and structural approaches. These complementary experimental techniques have permitted a detailed analysis into various processes of human DNA repair.
Date: February 16, 2000
Creator: Wilson, D. M., III
Object Type: Report
System: The UNT Digital Library
Chromaticity Measurements Using Phase Modulated RF and Vector Signal Analyzers (open access)

Chromaticity Measurements Using Phase Modulated RF and Vector Signal Analyzers

Chromaticity measurements are usually done by changing the energy of the beam by a known amount and measuring the change in betatron tune with a spectrum analyzer. The energy change is done by adjusting the RF frequency. The change in RF frequency is made large enough so that the change in betatron tune can be seen. If synchrotron motion is present in the beam, then measuring the change in betatron tune can be difficult. This note will outline a method to measure the change in betatron tune by phase-modulating the RF and measuring the phase modulated betatron spectrum Extremely small resolution bandwidths are available on modern vector signal analyzers. A small resolution bandwidth is equivalent to measuring the chromaticity many times and averaging the results. This would permit much smaller shifts in betatron tunes to be measured. The phase-modulated signal consists of sidebands whose amplitudes are given by Bessel functions. The complication of the Bessel functions can be removed if the vector signal analyzer is capable of phase demodulation. The sign of the chromaticity can be determined by observing the modulation spectrum at both betatron sidebands.
Date: February 16, 2001
Creator: McGinnis, Dave
Object Type: Report
System: The UNT Digital Library
Plant cell walls throughout evolution: towards a molecular understanding of their design principles (open access)

Plant cell walls throughout evolution: towards a molecular understanding of their design principles

Throughout their life, plants typically remain in one location utilizing sunlight for the synthesis of carbohydrates, which serve as their sole source of energy as well as building blocks of a protective extracellular matrix, called the cell wall. During the course of evolution, plants have repeatedly adapted to their respective niche,which is reflected in the changes of their body plan and the specific design of cell walls. Cell walls not only changed throughout evolution but also are constantly remodelled and reconstructed during the development of an individual plant, and in response to environmental stress or pathogen attacks. Carbohydrate-rich cell walls display complex designs, which together with the presence of phenolic polymers constitutes a barrier for microbes, fungi, and animals. Throughout evolution microbes have co-evolved strategies for efficient breakdown of cell walls. Our current understanding of cell walls and their evolutionary changes are limited as our knowledge is mainly derived from biochemical and genetic studies, complemented by a few targeted yet very informative imaging studies. Comprehensive plant cell wall models will aid in the re-design of plant cell walls for the purpose of commercially viable lignocellulosic biofuel production as well as for the timber, textile, and paper industries. Such knowledge will …
Date: February 16, 2009
Creator: Sarkar, Purbasha; Bosneaga, Elena & Auer, Manfred
Object Type: Article
System: The UNT Digital Library
Developing the Manufacturing Process for Hylene MP Curing Agent (open access)

Developing the Manufacturing Process for Hylene MP Curing Agent

This report details efforts to scale-up and re-establish the manufacturing process for the curing agent known as Hylene MP. First, small scale reactions were completed with varying conditions to determine key drivers for yielding high quality product. Once the optimum conditions were determined on the small scale, the scaled-up process conditions were determined. New equipment was incorporated into the manufacturing process to create a closed production system and improve chemical exposure controls and improve worker safety. A safe, efficient manufacturing process was developed to manufacture high quality Hylene MP in large quantities.
Date: February 16, 2009
Creator: Eastwood, Eric
Object Type: Report
System: The UNT Digital Library
Experimental and Sampling Design for the INL-2 Sample Collection Operational Test (open access)

Experimental and Sampling Design for the INL-2 Sample Collection Operational Test

This report describes the experimental and sampling design developed to assess sampling approaches and methods for detecting contamination in a building and clearing the building for use after decontamination. An Idaho National Laboratory (INL) building will be contaminated with BG (Bacillus globigii, renamed Bacillus atrophaeus), a simulant for Bacillus anthracis (BA). The contamination, sampling, decontamination, and re-sampling will occur per the experimental and sampling design. This INL-2 Sample Collection Operational Test is being planned by the Validated Sampling Plan Working Group (VSPWG). The primary objectives are: 1) Evaluate judgmental and probabilistic sampling for characterization as well as probabilistic and combined (judgment and probabilistic) sampling approaches for clearance, 2) Conduct these evaluations for gradient contamination (from low or moderate down to absent or undetectable) for different initial concentrations of the contaminant, 3) Explore judgment composite sampling approaches to reduce sample numbers, 4) Collect baseline data to serve as an indication of the actual levels of contamination in the tests. A combined judgmental and random (CJR) approach uses Bayesian methodology to combine judgmental and probabilistic samples to make clearance statements of the form "X% confidence that at least Y% of an area does not contain detectable contamination” (X%/Y% clearance statements). The INL-2 …
Date: February 16, 2009
Creator: Piepel, Gregory F.; Amidan, Brett G. & Matzke, Brett D.
Object Type: Report
System: The UNT Digital Library
HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT INCREASED LIQUID LEVEL ANALYSIS FOR 241-AP TANK FARMS (open access)

HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT INCREASED LIQUID LEVEL ANALYSIS FOR 241-AP TANK FARMS

The overall scope of the project is to complete an up-to-date comprehensive analysis of record of the SDT System at Hanford. The "Double-Shell Tank (DST) Integrity Project - DST Thermal and Seismic Project" is in support of Tri-Party Agreement Milestone M-48-14.
Date: February 16, 2007
Creator: Mackey, T. C.; Deibler, J. E.; Johnson, K. I.; Pilli, S. P.; Karri, N. K.; Rinker, M. W. et al.
Object Type: Report
System: The UNT Digital Library
The SEMATECH Berkeley microfield exposure tool: learning a the 22-nm node and beyond (open access)

The SEMATECH Berkeley microfield exposure tool: learning a the 22-nm node and beyond

Microfield exposure tools (METs) continue to playa dominant role in the development of extreme ultraviolet (EUV) resists. One of these tools is the SEMATECH Berkeley 0.3-NA MET operating as a SEMATECH resist and mask test center. Here we present an update summarizing the latest resist test and characterization results. The relatively small numerical aperture and limited illumination settings expected from 1st generation EUV production tools make resist resolution a critical issue even at the 32-nm node. In this presentation, sub 22 nm half pitch imaging results of EUV resists are reported. We also present contact hole printing at the 30-nm level. Although resist development has progressed relatively well in the areas of resolution and sensitivity, line-edge-roughness (LER) remains a significant concern. Here we present a summary of recent LER performance results and consider the effect of system-level contributors to the LER observed from the SEMA TECH Berkeley microfield tool.
Date: February 16, 2009
Creator: Naulleau, Patrick; Anderson, Christopher; Baclea-an, Lorie-Mae; Denham, Paul; George, Simi; Goldberg, Kenneth A. et al.
Object Type: Article
System: The UNT Digital Library
Selective Organic and Organometallic Reactions in Water-Soluble Host-Guest Supramolecular Systems (open access)

Selective Organic and Organometallic Reactions in Water-Soluble Host-Guest Supramolecular Systems

Inspired by the efficiency and selectivity of enzymes, synthetic chemists have designed and prepared a wide range of host molecules that can bind smaller molecules with their cavities; this area has become known as 'supramolecular' or 'host-guest' chemistry. Pioneered by Lehn, Cram, Pedersen, and Breslow, and followed up by a large number of more recent investigators, it has been found that the chemical environment in each assembly - defined by the size, shape, charge, and functional group availability - greatly influences the guest-binding characteristics of these compounds. In contrast to the large number of binding studies that have been carried out in this area, the exploration of chemistry - especially catalytic chemistry - that can take place inside supramolecular host cavities is still in its infancy. For example, until the work described here was carried out, very few examples of organometallic reactivity inside supramolecular hosts were known, especially in water solution. For that reason, our group and the group directed by Kenneth Raymond decided to take advantage of our complementary expertise and attempt to carry out metal-mediated C-H bond activation reactions in water-soluble supramolecular systems. This article begins by providing background from the Raymond group in supramolecular coordination chemistry and …
Date: February 16, 2008
Creator: Pluth, Michael D.; Raymond, Kenneth N. & Bergman, Robert G.
Object Type: Report
System: The UNT Digital Library
Measurement of the Cosmic Ray and Neutrino-Induced Muon Flux at the Sudbury Neutrino Observatory (open access)

Measurement of the Cosmic Ray and Neutrino-Induced Muon Flux at the Sudbury Neutrino Observatory

Results are reported on the measurement of the atmospheric neutrino-induced muon flux at a depth of 2 kilometers below the Earth's surface from 1229 days of operation of the Sudbury Neutrino Observatory (SNO). By measuring the flux of through-going muons as a function of zenith angle, the SNO experiment can distinguish between the oscillated and un-oscillated portion of the neutrino flux. A total of 514 muon-like events are measured between -1 {le} cos {theta}{sub zenith} 0.4 in a total exposure of 2.30 x 10{sup 14} cm{sup 2} s. The measured flux normalization is 1.22 {+-} 0.09 times the Bartol three-dimensional flux prediction. This is the first measurement of the neutrino-induced flux where neutrino oscillations are minimized. The zenith distribution is consistent with previously measured atmospheric neutrino oscillation parameters. The cosmic ray muon flux at SNO with zenith angle cos {theta}{sub zenith} > 0.4 is measured to be (3.31 {+-} 0.01 (stat.) {+-} 0.09 (sys.)) x 10{sup -10} {micro}/s/cm{sup 2}.
Date: February 16, 2009
Creator: SNO Collaboration; Aharmim, B.; Ahmed, S. N.; Andersen, T. C.; Anthony, A. E.; Barros, N. et al.
Object Type: Article
System: The UNT Digital Library
Proceedings of RIKIN BNL Research Center Workshop - Volume 79 (open access)

Proceedings of RIKIN BNL Research Center Workshop - Volume 79

Since the earliest days of ultra-relativistic heavy ion physics, there has been interest in strange particle production. Originally, an anomalously large strangeness production was believed to be a signature of the Quark Gluon Plasma. Now the flavor composition of the plasma as reflected in the ratios of abundances of strange and non-strange particles is believed by advocates to tell us the temperature and baryon number density of the Quark Gluon Plasma at decoupling. In addition, there are arguments that suggest that the abundances of strange particles might at intermediate energy or at non-central rapidity, signal the existence of a critical end point of phase transitions in the baryon number chemical potential temperature plane. The purpose of this workshop is to assess the current theoretical and experimental understanding of strangeness production for ultra-relativistic heavy ion collisions.
Date: February 16, 2006
Creator: Samios, N.
Object Type: Article
System: The UNT Digital Library
Revisiting the total ion yield x-ray absorption spectra of liquid water microjets (open access)

Revisiting the total ion yield x-ray absorption spectra of liquid water microjets

Measurements of the total ion yield (TIY) x-ray absorption spectrum (XAS) of liquid water by Wilson et al. (2002 J. Phys.: Condens. Matter 14 L221 and 2001 J. Phys. Chem. B 105 3346) have been revisited in light of new experimental and theoretical efforts by our group. Previously, the TIY spectrum was interpreted as a distinct measure of the electronic structure of the liquid water surface. However, our new results indicate that the previously obtained spectrum may have suffered from as yet unidentified experimental artifacts. Although computational results indicate that the liquid water surface should exhibit a TIY-XAS that is fundamentally distinguishable from the bulk liquid XAS, the new experimental results suggest that the observable TIY-XAS is actually nearly identical in appearance to the total electron yield (TEY-)XAS, which is a bulk probe. This surprising similarity between the observed TIY-XAS and TEY-XAS likely results from large contributions from x-ray induced electron stimulated desorption of ions, and does not necessarily indicate that the electronic structure of the bulk liquid and liquid surface are identical.
Date: February 16, 2008
Creator: Saykally, Richard J; Cappa, Chris D.; Smith, Jared D.; Wilson, Kevin R. & Saykally, Richard J.
Object Type: Article
System: The UNT Digital Library