Experimental Study of Three-body Cabibbo-suppressed D0 Decays and Extraction of Cp Violation Parameters (open access)

Experimental Study of Three-body Cabibbo-suppressed D0 Decays and Extraction of Cp Violation Parameters

The authors present measurements of the relative branching ratios, Dalitz plot structures and CP-asymmetry values in the three-body singly Cabibbo-suppressed decays D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup 0} and D{sup 0} {yields} K{sup -}K{sup +}{pi}{sup 0} using data collected by the BABAR detector at the PEP-II asymmetric-energy ring at SLAC. The author applies the results of the D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup 0} analysis to extracting CP-violation parameters related to the CKM angle {gamma} (or {phi}{sub 3}) using the decay B{sup -} {yields} D{sub {pi}{sup +}{pi}{sup -}{pi}{sup 0}} K{sup -}.
Date: February 22, 2008
Creator: Mishra, Kalanand & U., /Nehru
Object Type: Report
System: The UNT Digital Library
Sulfidation of Cadmium at the Nanoscale (open access)

Sulfidation of Cadmium at the Nanoscale

We investigate the evolution of structures that result when spherical Cd nanoparticles of a few hundred nanometers in diameter react with dissolved molecular sulfur species in solution to form hollow CdS. Over a wide range of temperatures and concentrations, we find that rapid Cd diffusion through the growing CdS shell localizes the reaction front at the outermost CdS/S interface, leading to hollow particles when all the Cd is consumed. When we examine partially reacted particles, we find that this system differs significantly from others in which the nanoscale Kirkendall effect has been used to create hollow particles. In previously reported systems, partial reaction creates a hollow particle with a spherically symmetric metal core connected to the outer shell by filaments. In contrast, here we obtain a lower symmetry structure, in which the unreacted metal core and the coalesced vacancies separate into two distinct spherical caps, minimizing the metal/void interface. This pattern of void coalescence is likely to occur in situations where the metal/vacancy self-diffusivities in the core are greater than the diffusivity of the cations through the shell.
Date: May 22, 2008
Creator: Cabot, Andreu; Smith, Rachel; Yin, Yadong; Zheng, Haimei; Reinhard, Bjorn; Liu, Haitao et al.
Object Type: Article
System: The UNT Digital Library
A high-throughput contact-hole resolution metric for photoresists:Full-process sensitivity study (open access)

A high-throughput contact-hole resolution metric for photoresists:Full-process sensitivity study

The ability to accurately quantify the intrinsic resolution of chemically amplified photoresists is critical for the optimization of resists for extreme ultraviolet (EUV) Iithography. We have recently reported on two resolution metrics that have been shown to extract resolution numbers consistent with direct observation. In this paper we examine the previously reported contact-hole resolution metric and explore the sensitivity of the metric to potential error sources associated with the experimental side of the resolution extraction process. For EUV exposures at the SEMATECH Berkeley microfield exposure tool, we report a full-process error-bar in extracted resolution of 1.75 nm RMS and verify this result experimentally.
Date: January 22, 2008
Creator: Anderson, Christopher N. & Naulleau, Patrick P.
Object Type: Article
System: The UNT Digital Library
TANK FARM RETRIEVAL LESSONS LEARNED AT THE HANFORD SITE (open access)

TANK FARM RETRIEVAL LESSONS LEARNED AT THE HANFORD SITE

One of the environmental remediation challenges facing the nation is the retrieval and permanent disposal of approximately 90 million gallons of radioactive waste stored in underground tanks at the U. S. Department of Energy (DOE) facilities. The Hanford Site is located in southeastern Washington State and stores roughly 60 percent of this waste. An estimated 53 million gallons of high-level, transuranic, and low-level radioactive waste is stored underground in 149 single-shell tanks (SSTs) and 28 newer double-shell tanks (DSTs) at the Hanford Site. These SSTs range in size from 55,000 gallons to 1,000,000 gallon capacity. Approximately 30 million gallons of this waste is stored in SSTs. The SSTs were constructed between 1943 and 1964 and all have exceeded the nominal 20-year design life. Sixty-seven SSTs are known or suspected to have leaked an estimated 1,000,000 gallons of waste to the surrounding soil. The risk of additional SST leakage has been greatly reduced by removing more than 3 million gallons of interstitial liquids and supernatant and transferring this waste to the DST system. Retrieval of SST saltcake and sludge waste is underway to further reduce risks and stage feed materials for the Hanford Site Waste Treatment Plant. Regulatory requirements for SST …
Date: January 22, 2008
Creator: RA, DODD
Object Type: Article
System: The UNT Digital Library
The Third Image of the Large-Separation Lensed Quasar SDSS J1029+2623 (open access)

The Third Image of the Large-Separation Lensed Quasar SDSS J1029+2623

We identify a third image in the unique quasar lens SDSS J1029+2623, the second known quasar lens produced by a massive cluster of galaxies. The spectrum of the third image shows similar emission and absorption features, but has a redder continuum than the other two images which can be explained by differential extinction or microlensing. We also identify several lensed arcs. Our observations suggest a complicated structure of the lens cluster at z {approx} 0.6. We argue that the three lensed images are produced by a naked cusp on the basis of successful mass models, the distribution of cluster member galaxies, and the shapes and locations of the lensed arcs. Lensing by a naked cusp is quite rare among galaxy-scale lenses but is predicted to be common among large-separation lensed quasars. Thus the discovery can be viewed as support for an important theoretical prediction of the standard cold dark matter model.
Date: February 22, 2008
Creator: Oguri, Masamune; Ofek, Eran O.; Inada, Naohisa; Morokuma, Tomoki; Falco, Emilio E.; Kochanek, Christopher S. et al.
Object Type: Article
System: The UNT Digital Library
Sum Frequency Generation Vibrational Spectroscopy of Pyridine Hydrogenation on Platinum Nanoparticles (open access)

Sum Frequency Generation Vibrational Spectroscopy of Pyridine Hydrogenation on Platinum Nanoparticles

Pyridine hydrogenation in the presence of a surface monolayer consisting of cubic Pt nanoparticles stabilized by tetradecyltrimethylammonium bromide (TTAB) was investigated by sum frequency generation (SFG) vibrational spectroscopy using total internal reflection (TIR) geometry. TIR-SFG spectra analysis revealed that a pyridinium cation (C{sub 5}H{sub 5}NH{sup +}) forms during pyridine hydrogenation on the Pt nanoparticle surface, and the NH group in the C{sub 5}H{sub 5}NH{sup +} cation becomes more hydrogen bound with the increase of the temperature. In addition, the surface coverage of the cation decreases with the increase of the temperature. An important contribution of this study is the in situ identification of reaction intermediates adsorbed on the Pt nanoparticle monolayer during pyridine hydrogenation.
Date: February 22, 2008
Creator: Bratlie, Kaitlin M.; Komvopoulos, Kyriakos & Somorjai, Gabor A.
Object Type: Article
System: The UNT Digital Library
Report on the Depth Requirements for a Massive Detector at Homestake (open access)

Report on the Depth Requirements for a Massive Detector at Homestake

This report provides the technical justification for locating a large detector underground in a US based Deep Underground Science and Engineering Laboratory. A large detector with a fiducial mass greater than 100 kTon will most likely be a multipurpose facility. The main physics justification for such a device is detection of accelerator generated neutrinos, nucleon decay, and natural sources of neutrinos such as solar, atmospheric and supernova neutrinos. The requirement on the depth of this detector will be guided by the rate of signals from these sources and the rate of backgrounds from cosmic rays over a very wide range of energies (from solar neutrino energies of 5 MeV to high energies in the range of tens of GeV). For the present report, we have examined the depth requirement for a large water Cherenkov detector and a liquid argon time projection chamber. There has been extensive previous experience with underground water Cherenkov detectors such as IMB, Kamioka, and most recently, Super-Kamiokande which has a fiducial mass of 22 kTon and a total mass of 50 kTon at a depth of 2700 meters-water-equivalent. Projections for signal and background capability for a larger and deeper (or shallower) detectors of this type can …
Date: December 22, 2008
Creator: Bernstein,A.; Blucher, E.; Cline, D. B.; Diwan, M. V.; Fleming, b.; Kadel, R. et al.
Object Type: Report
System: The UNT Digital Library
Dissipative Cryogenic Filters with Zero DC Resistance (open access)

Dissipative Cryogenic Filters with Zero DC Resistance

The authors designed, implemented and tested cryogenic RF filters with zero DC resistance, based on wires with a superconducting core inside a resistive sheath. The superconducting core allows low frequency currents to pass with negligible dissipation. Signals above the cutoff frequency are dissipated in the resistive part due to their small skin depth. The filters consist of twisted wire pairs shielded with copper tape. Above approximately 1 GHz, the attenuation is exponential in {radical}{omega}, as typical for skin depth based RF filters. By using additional capacitors of 10 nF per line, an attenuation of at least 45 dB above 10 MHz can be obtained. Thus, one single filter stage kept at mixing chamber temperature in a dilution refrigerator is sufficient to attenuate room temperature black body radiation to levels corresponding to 10 mK above about 10 MHz.
Date: April 22, 2008
Creator: Bluhm, Hendrik; Moler, Kathryn A. & /Stanford U., Appl. Phys. Dept
Object Type: Article
System: The UNT Digital Library
FILL STEM MANUFACTURING CHANGES AND PINCH WELD QUALIFICATIONS (open access)

FILL STEM MANUFACTURING CHANGES AND PINCH WELD QUALIFICATIONS

In March of 2007 a document was issued, see attachment I, that defined the test protocol and required welding for the Kansas City Plant to change cutting oils from the recently approved 50:50 oil to an oil with similar characteristics but with different chemistry, additives, and possibly a different vendor due to plans by the current vendor to stop preparing the oils that are used in the KCP 50:50 mix. The KCP manufactured stems with the existing 50:50 oil blend in late FY07 and SRNL welded the stems and evaluated them in agreement with the test plan. This report provides all the data from these set-up and test welds. Set-up welds were shot and low and high voltages (currents) to ensure the window limits were applicable and then additional welds were made to validate the window. The purpose of this report is to ensure that the agreed upon path forward is still applicable.
Date: February 22, 2008
Creator: Korinko, P & David Maxwell, D
Object Type: Report
System: The UNT Digital Library
ENVIRONMENTAL SAMPLING AND ANALYSIS - GETTING IT RIGHT (open access)

ENVIRONMENTAL SAMPLING AND ANALYSIS - GETTING IT RIGHT

The Department of Energy's Hanford Site in southeastern Washington State was established in the 1940s as part of the Manhattan Project. Hanford's role was to produce weapons-grade nuclear material for defense, and by 1989, when the Site's mission changed from operations to cleanup, Hanford had produced more than 60 percent of the nation's plutonium. The legacy of Hanford's production years is enormous in terms of nuclear and hazardous waste, especially the 270 billion gallons of contaminated groundwater and the 5 million cubic yards of contaminated soil. Managing the contaminated soil and groundwater are particularly important because the Columbia River, the lifeblood of the northwest and the nation's eighth largest river, bounds the Site. Fluor Hanford's Soil & Groundwater Remediation Project (S&GRP) integrates all of the activities that deal with remediating and monitoring the groundwater across the Site. The S&GRP uses a detailed series of steps to record, track, and verify information. The Sample and Data Management (SDM) Process consists of 10 integrated steps that start with the data quality objectives process that establishes the mechanism for collecting the right information with the right people. The process ends with data quality assessment, which is used to ensure that all quantitative data …
Date: January 22, 2008
Creator: CW, CONNELL
Object Type: Article
System: The UNT Digital Library
Information Resources in High-Energy Physics: Surveying the Present Landscape and Charting the Future Course (open access)

Information Resources in High-Energy Physics: Surveying the Present Landscape and Charting the Future Course

Access to previous results is of paramount importance in the scientific process. Recent progress in information management focuses on building e-infrastructures for the optimization of the research workflow, through both policy-driven and user-pulled dynamics. For decades, High-Energy Physics (HEP) has pioneered innovative solutions in the field of information management and dissemination. In light of a transforming information environment, it is important to assess the current usage of information resources by researchers and HEP provides a unique test-bed for this assessment. A survey of about 10% of practitioners in the field reveals usage trends and information needs. Community-based services, such as the pioneering arXiv and SPIRES systems, largely answer the need of the scientists, with a limited but increasing fraction of younger users relying on Google. Commercial services offered by publishers or database vendors are essentially unused in the field. The survey offers an insight into the most important features that users require to optimize their research workflow. These results inform the future evolution of information management in HEP and, as these researchers are traditionally 'early adopters' of innovation in scholarly communication, can inspire developments of disciplinary repositories serving other communities.
Date: April 22, 2008
Creator: Gentil-Beccot, Anne; Mele, Salvatore; Holtkamp, Annette; O'Connell, Heath B. & Brooks, Travis C.
Object Type: Article
System: The UNT Digital Library
Characterizing the nano and micro structure of concrete to improve its durability (open access)

Characterizing the nano and micro structure of concrete to improve its durability

New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images on ice inside cement paste and cracking caused by the alkali-silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools will be shown on this paper.
Date: October 22, 2008
Creator: Monteiro, P. J. M.; Kirchheim, A. P.; Chae, S.; Fischer, P.; MacDowell, A. A.; Schaible, E. et al.
Object Type: Article
System: The UNT Digital Library
Modification of the GS LT Paired-end Library Protocol for Constructing Longer Insert Size Libraries (open access)

Modification of the GS LT Paired-end Library Protocol for Constructing Longer Insert Size Libraries

Paired-end library sequencing has been proven useful in scaffold construction during de novo assembly of genomic sequences. The ability of generating mate pairs with 8 Kb or greater insert sizes is especially important for genomes containing long repeats. While the current 454 GS LT Paired-end library preparation protocol can successfully construct libraries with 3 Kb insert size, it fails to generate longer insert sizes because the protocol is optimized to purify shorter fragments. We have made several changes in the protocol in order to increase the fragment length. These changes include the use of Promega column to increase the yield of large size DNA fragments, two gel purification steps to remove contaminated short fragments, and a large reaction volume in the circularization step to decrease the formation of chimeras. We have also made additional changes in the protocol to increase the overall quality of the libraries. The quality of the libraries are measured by a set of metrics, which include levels of redundant reads, linker positive, linker negative, half linker reads, and driver DNA contamination, and read length distribution, were used to measure the primary quality of these libraries. We have also assessed the quality of the resulted mate pairs …
Date: May 22, 2008
Creator: Peng, Ze; Peng, Ze; Hamilton, Matthew; Ting, Sara; Tu, Hank; Goltsman, Eugene et al.
Object Type: Report
System: The UNT Digital Library
Recent Searches for Exotic Physics at the BaBar/PEP-II B-factory (open access)

Recent Searches for Exotic Physics at the BaBar/PEP-II B-factory

I present three recent results from searches for exotic physics at the BABAR/PEP-II B-factory. These results span many of the samples produced at the B-factory, including B mesons, {tau} leptons, and {Upsilon}(3S) mesons. We have searched for CPT-violation in B{sup 0} mixing and find no significant deviation from the no-violation hypothesis. We have also searched for lepton-flavor-violating decays of the {tau} using {tau}{sup -} {yields} {omega}{ell}{sup -} and {tau}{sup -} {yields} {ell}{sup -}{ell}{sup +}{ell}{sup -} and their charge conjugates. We find no evidence for these processes and set upper limits on their branching fractions. Finally, we have searched for a low-mass Higgs boson in the decay {Upsilon}(3S) {yields} {gamma}A{sup 0}, where the Higgs decays invisibly. We find no evidence for such a decay and set upper limits across a range of possible Higgs masses.
Date: October 22, 2008
Creator: Sekula, Stephen Jacob
Object Type: Article
System: The UNT Digital Library
Isotopic approach for determining the structural components of silicate liquids (open access)

Isotopic approach for determining the structural components of silicate liquids

None
Date: February 22, 2008
Creator: Watkins, J J; Ryerson, F J & DePaolo, D .
Object Type: Article
System: The UNT Digital Library
Science & Technology Review March/April 2008 (open access)

Science & Technology Review March/April 2008

This month's issue has the following articles: (1) Science and Security in Sharp Focus--Commentary by William H. Goldstein; (2) Extending the Search for Extrasolar Planets--The Gemini Planet Imager will delve deep into the universe to identify planets that cannot be detected with current instrumentation; (3) Standardizing the Art of Electron-Beam Welding--The Laboratory's EBeam Profiler makes electron-beam welds consistent and improves quality control; (4) Molecular Building Blocks Made of Diamonds--Livermore physicists are exploring the electrical properties of diamondoids, tiny molecules of diamond; and (5) Animation Brings Science to Life--Animation helps scientists and engineers effectively communicate their ideas and research in a visually compelling way.
Date: January 22, 2008
Creator: Chinn, D J
Object Type: Report
System: The UNT Digital Library
Observation of B^+\to\eta\rho^+ and Search for B^0 Decays to\eta^\prime\eta, \eta\pi^0, \eta^\prime\pi^0, and \omega\pi^0 (open access)

Observation of B^+\to\eta\rho^+ and Search for B^0 Decays to\eta^\prime\eta, \eta\pi^0, \eta^\prime\pi^0, and \omega\pi^0

The authors present measurements of branching fractions for five B-meson decays to two-body charmless final states. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 459 million B{bar B} pairs. The results for branching fractions are, in units of 10{sup -6} (upper limits at 90% C.L.): {Beta}(B{sup +} {yields} {eta}{rho}{sup +}) = 9.9 {+-} 1.2 {+-} 0.8, {Beta}(B{sup 0} {yields} {eta}{prime}{eta}) = 0.5 {+-} 0.4 {+-} 0.1 (< 1.2), {Beta}(B{sup 0} {yields} {eta}{pi}{sup 0}) = 0.9 {+-} 0.4 {+-} 0.1 (< 1.5), {Beta}(B{sup 0} {yields} {eta}{prime}{pi}{sup 0}) = 0.9 {+-} 0.4 {+-} 0.1 (< 1.5), and {Beta}(B{sup 0}{sup 0} {yields} {omega}{pi}{sup 0}) = {eta}{rho}{sup +} mode, they measure the charge asymmetry {Alpha}{sub ch} (B{sup +} {yields} {eta}{rho}{sup +}) = 0.13 {+-} 0.11 {+-} 0.02.
Date: April 22, 2008
Creator: Aubert, Bernard; Bona, Marcella; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Object Type: Article
System: The UNT Digital Library
DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF NUCLEAR WASTE AT THE SAVANNAH RIVER SITE (open access)

DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove Cs-137, Sr-90 and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include sorption of Sr-90 and alpha-emitting radionuclides onto monosodium titanate (MST) and caustic side solvent extraction, for Cs-137 removal. The MST and separated Cs-137 will be encapsulated into a borosilicate glass waste form for eventual entombment at the federal repository. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes Pu-238, Pu-239 and Pu-240. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for Sr-90 and alpha-emitting radionuclides compared to the baseline MST material.
Date: January 22, 2008
Creator: Hobbs, D
Object Type: Article
System: The UNT Digital Library
Polypeptide and Polysaccharide Processing in Hyperthermophilic Microorganisms (open access)

Polypeptide and Polysaccharide Processing in Hyperthermophilic Microorganisms

This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.
Date: December 22, 2008
Creator: Kelly, Robert M.
Object Type: Report
System: The UNT Digital Library
LINAC DESIGN FOR AN ARRAY OF SOFT X-RAY FREE ELECTRON LASERS (open access)

LINAC DESIGN FOR AN ARRAY OF SOFT X-RAY FREE ELECTRON LASERS

The design of the linac delivering electron bunches into ten independent soft x-ray free electron lasers (FELs) producing light at 1 nm and longer wavelengths is presented. The bunch repetition rate in the linac is 1 MHz and 100 kHz in each of ten FEL beam lines. Various issues regarding machine layout and lattice, bunch compression, collimation, and the beam switch yard are discussed. Particular attention is given to collective effects. A demanding goal is to preserve both a low beam slice emittance and low slice energy spread during acceleration, bunch compression and distribution of the electron bunches into the array of FEL beamlines. Detailed studies of the effect of the electron beam microbunching caused by longitudinal space-charge forces and coherent synchrotron radiation (CSR) have been carried out and their results are presented.
Date: September 22, 2008
Creator: Zholents, Alexander A.; Kur, E.; Penn, G.; Qiang, Ji; Venturini, M. & Wells, R. P.
Object Type: Article
System: The UNT Digital Library
Regulating Intracellular Calcium in Plants: From Molecular Genetics to Physiology (open access)

Regulating Intracellular Calcium in Plants: From Molecular Genetics to Physiology

To grow, develop, adapt, and reproduce, plants have evolved mechanisms to regulate the uptake, translocation and sorting of calcium ions into different cells and subcellular compartments. Yet how plants accomplish this remarkable feat is still poorly understood. The spatial and temporal changes in intracellular [Ca2+] during growth and during responses to hormonal and environmental stimuli indicate that Ca2+ influx and efflux transporters are diverse and tightly regulated in plants. The specific goals were to determine the biological roles of multiple Ca pumps (ECAs) in the model plant Arabidopsis thaliana. We had pioneered the use of K616 yeast strain to functionally express plant Ca pumps, and demonstrated two distinct types of Ca pumps in plants (Sze et al., 2000. Annu Rev Plant Biol. 51,433). ACA2 represented one type that was auto-inhibited by the N-terminal region and stimulated by calmodulin. ECA1 represented another type that was not sensitive to calmodulin and phylogenetically distinct from ACAs. The goal to determine the biological roles of multiple ECA-type Ca pumps in Arabidopsis has been accomplished. Although we demonstrated ECA1 was a Ca pump by functional expression in yeast, the in vivo roles of ECAs was unclear. A few highlights are described. ECA1 and/or ECA4 are …
Date: June 22, 2008
Creator: Sze, Heven
Object Type: Report
System: The UNT Digital Library
PROGRESS IN HANFORDS DOUBLE SHELL TANK (DST) INTEGRITY PROJECT (open access)

PROGRESS IN HANFORDS DOUBLE SHELL TANK (DST) INTEGRITY PROJECT

The U.S. Department of Energy's Office of River Protection has an extensive integrity assessment program for the Hanford Site Double-Shell Tank System. The DOE Orders and environmental protection regulations provide the guidelines for the activities used to inspect and maintain 28 double-shell tanks (DSTs), the waste evaporator, and ancillary equipment that compose this system. This program has been reviewed by oversight and regulatory bodies and found to comply with the established guidelines. The basis for the DOE Order 435.1-1 for tank integrity comes from the Tank Structural Integrity Paneled by Brookhaven National Laboratory during the late 1990s. These guidelines established criteria for performing Non-Destructive Examination (NDE), for acceptance of the NDE results, for waste chemistry control, and for monitoring the tanks. The environmental regulations mirror these requirements and allow for the tank integrity program to provide compliant storage of the tanks. Both sets of requirements provide additional guidance for the protection of ancillary equipment. CH2M HILL uses two methods of NDE: visual inspection and Ultrasonic Testing (UT). The visual inspection program examines the primary tank and secondary liner of the DST. The primary tank is examined both on the interior surface above the waste in the tank and on the …
Date: January 22, 2008
Creator: HS, BERMAN
Object Type: Article
System: The UNT Digital Library
Annual Site Environmental Report: 2006 (open access)

Annual Site Environmental Report: 2006

This report provides information about environmental programs during the calendar year (CY) of 2006 at the Stanford Linear Accelerator Center (SLAC), Menlo Park, California. Activities that span the calendar year; i.e., stormwater monitoring covering the winter season of 2006/2007 (October 2006 through May 2007), are also included. Production of an annual site environmental report (ASER) is a requirement established by the United States Department of Energy (DOE) for all management and operating (M&O) contractors throughout the DOE complex. SLAC is a federally-funded research and development center with Stanford University as the M&O contractor. SLAC continued to follow the path to self-declare an environmental management system under DOE Order 450.1, 'Environmental Protection Program' and effectively applied environmental management in meeting the site's integrated safety and environmental management system goals. For normal daily activities, all SLAC managers and supervisors are responsible for ensuring that proper procedures are followed so that Worker safety and health are protected; The environment is protected; and Compliance is ensured. Throughout 2006, SLAC focused on these activities through the SLAC management systems. These systems were also the way SLAC approached implementing 'greening of the government' initiatives such as Executive Order 13148. The management systems at SLAC are effective, …
Date: February 22, 2008
Creator: Nuckolls, H.
Object Type: Report
System: The UNT Digital Library
Ion Partitioning at the liquid/vapor interface of a multi-component alkali halidesolution: A model for aqueous sea salt aerosols (open access)

Ion Partitioning at the liquid/vapor interface of a multi-component alkali halidesolution: A model for aqueous sea salt aerosols

The chemistry of Br species associated with sea salt ice and aerosols has been implicated in the episodes of ozone depletion reported at Arctic sunrise. However, Br{sup -} is only a minor component in sea salt, which has a Br{sup -}/Cl{sup -} molar ratio of {approx}0.0015. Sea salt is a complex mixture of many different species, with NaCl as the primary component. In recent years experimental and theoretical studies have reported enhancement of the large, more polarizable halide ion at the liquid/vapor interface of corresponding aqueous alkali halide solutions. The proposed enhancement is likely to influence the availability of sea salt Br{sup -} for heterogeneous reactions such as those involved in the ozone depletion episodes. We report here ambient pressure x-ray photoelectron spectroscopy studies and molecular dynamics simulations showing direct evidence of Br{sup -} enhancement at the interface of an aqueous NaCl solution doped with bromide. The experiments were carried out on samples with Br{sup -}/Cl{sup -} ratios in the range 0.1% to 10%, the latter being also the ratio for which simulations were carried out. This is the first direct measurement of interfacial enhancement of Br{sup -} in a multi-component solution with particular relevance to sea salt chemistry.
Date: December 22, 2008
Creator: Ghosal, Sutapa; Brown, Matthew A.; Bluhm, Hendrik; Krisch, Maria J.; Salmeron, Miquel; Jungwirth, Pavel et al.
Object Type: Article
System: The UNT Digital Library