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Aza Cope Rearrangement of Propargyl Enammonium Cations Catalyzed By a Self-Assembled `Nanozyme (open access)

Aza Cope Rearrangement of Propargyl Enammonium Cations Catalyzed By a Self-Assembled `Nanozyme

The tetrahedral [Ga{sub 4}L{sub 6}]{sup 12-} assembly (L = N,N-bis(2,3-dihydroxybenzoyl)-1,5-diaminonaphthalene) encapsulates a variety of cations, including propargyl enammonium cations capable of undergoing the aza Cope rearrangement. For propargyl enammonium substrates that are encapsulated in the [Ga{sub 4}L{sub 6}]{sup 12-} assembly, rate accelerations of up to 184 are observed when compared to the background reaction. After rearrangement, the product iminium ion is released into solution and hydrolyzed allowing for catalytic turnover. The activation parameters for the catalyzed and uncatalyzed reaction were determined, revealing that a lowered entropy of activation is responsible for the observed rate enhancements. The catalyzed reaction exhibits saturation kinetics; the rate data obey the Michaelis-Menten model of enzyme kinetics, and competitive inhibition using a non-reactive guest has been demonstrated.
Date: February 27, 2008
Creator: Hastings, Courntey J.; Fiedler, Dorothea; Bergman, Robert G. & Raymond, Kenneth N.
System: The UNT Digital Library
Expression profiling of hypothetical genes in Desulfovibrio vulgaris leads to improved functional annotation (open access)

Expression profiling of hypothetical genes in Desulfovibrio vulgaris leads to improved functional annotation

Hypothetical and conserved hypothetical genes account for>30percent of sequenced bacterial genomes. For the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough, 347 of the 3634 genes were annotated as conserved hypothetical (9.5percent) along with 887 hypothetical genes (24.4percent). Given the large fraction of the genome, it is plausible that some of these genes serve critical cellular roles. The study goals were to determine which genes were expressed and provide a more functionally based annotation. To accomplish this, expression profiles of 1234 hypothetical and conserved genes were used from transcriptomic datasets of 11 environmental stresses, complemented with shotgun LC-MS/MS and AMT tag proteomic data. Genes were divided into putatively polycistronic operons and those predicted to be monocistronic, then classified by basal expression levels and grouped according to changes in expression for one or multiple stresses. 1212 of these genes were transcribed with 786 producing detectable proteins. There was no evidence for expression of 17 predicted genes. Except for the latter, monocistronic gene annotation was expanded using the above criteria along with matching Clusters of Orthologous Groups. Polycistronic genes were annotated in the same manner with inferences from their proximity to more confidently annotated genes. Two targeted deletion mutants were used as test cases to …
Date: October 27, 2008
Creator: Elias, Dwayne A.; Mukhopadhyay, Aindrila; Joachimiak, Marcin P.; Drury, Elliott C.; Redding, Alyssa M.; Yen, Huei-Che B. et al.
System: The UNT Digital Library
Atomic Physics in the Quest for Fusion Energy and ITER (open access)

Atomic Physics in the Quest for Fusion Energy and ITER

The urgent quest for new energy sources has led developed countries, representing over half of the world population, to collaborate on demonstrating the scientific and technological feasibility of magnetic fusion through the construction and operation of ITER. Data on high-Z ions will be important in this quest. Tungsten plasma facing components have the necessary low erosion rates and low tritium retention but the high radiative efficiency of tungsten ions leads to stringent restrictions on the concentration of tungsten ions in the burning plasma. The influx of tungsten to the burning plasma will need to be diagnosed, understood and stringently controlled. Expanded knowledge of the atomic physics of neutral and ionized tungsten will be important to monitor impurity influxes and derive tungsten concentrations. Also, inert gases such as argon and xenon will be used to dissipate the heat flux flowing to the divertor. This article will summarize the spectroscopic diagnostics planned for ITER and outline areas where additional data is needed.
Date: February 27, 2008
Creator: Skinner, Charles H.
System: The UNT Digital Library
RAPID SEPARATION METHOD FOR EMERGENCY WATER AND URINE SAMPLES (open access)

RAPID SEPARATION METHOD FOR EMERGENCY WATER AND URINE SAMPLES

The Savannah River Site Environmental Bioassay Lab participated in the 2008 NRIP Emergency Response program administered by the National Institute for Standards and Technology (NIST) in May, 2008. A new rapid column separation method was used for analysis of actinides and {sup 90}Sr the NRIP 2008 emergency water and urine samples. Significant method improvements were applied to reduce analytical times. As a result, much faster analysis times were achieved, less than 3 hours for determination of {sup 90}Sr and 3-4 hours for actinides. This represents a 25%-33% improvement in analysis times from NRIP 2007 and a {approx}100% improvement compared to NRIP 2006 report times. Column flow rates were increased by a factor of two, with no significant adverse impact on the method performance. Larger sample aliquots, shorter count times, faster cerium fluoride microprecipitation and streamlined calcium phosphate precipitation were also employed. Based on initial feedback from NIST, the SRS Environmental Bioassay Lab had the most rapid analysis times for actinides and {sup 90}Sr analyses for NRIP 2008 emergency urine samples. High levels of potential matrix interferences may be present in emergency samples and rugged methods are essential. Extremely high levels of {sup 210}Po were found to have an adverse effect …
Date: August 27, 2008
Creator: Maxwell, S. & Culligan, B.
System: The UNT Digital Library
Long Baseline Neutrino Beams and Large Detectors (open access)

Long Baseline Neutrino Beams and Large Detectors

It is amazing to acknowledge that in roughly 70 years from when the existence of the neutrino was postulated, we are now contemplating investigating the mysteries of this particle (or particles) requiring and utilizing detectors of 300 ktons , distances of 1,000-2,000 kilometers, beam intensities of megawatts and underground depth of 5,000 feet. This evolution has evolved slowly, from the experimental discovery of the neutrino in 1956, to the demonstration that there were two neutrinos in 1962 and three and only three by 1991. The great excitement occurred in the 2000's coming from the study of solar and atmospheric neutrinos in which neutrinos were observed to oscillate and therefore have mass. Although the absolute mass of any of the neutrinos has yet to be determined (the upper limit is less than I electron volt) the difference in this square of these masses has been measured, yielding a value of (2.3 {+-} .2) 10{sup -3} ev{sup 2} for atmospheric neutrinos and (7.6 {+-} .2) 10{sup -5} ev{sup 2} for solar neutrinos. In addition their mixing angles were found to be 45{sup o} for atmospheric neutrinos and 34{sup o} for solar neutrinos. This present state of knowledge on neutrinos is pictorially displayed …
Date: October 27, 2008
Creator: Samios, N. P.
System: The UNT Digital Library
Hyperon Polarization in Unpolarized Scattering Processes (open access)

Hyperon Polarization in Unpolarized Scattering Processes

Transverse polarization in the Hyperon (\Lambda) production in the unpolarizeddeep inelastic scattering and pp collisions is studied in the twist-three approach, considering the contribution from the quark-gluon-antiquark correlation distribution in nucleon. We further compare our results for deep inelastic scattering to a transverse momentum dependent factorization approach, and find consistency between the two approaches in the intermediate transverse momentum region. We also find that in pp collisions, there are only derivative terms contributions, and the non-derivative terms vanish.
Date: August 27, 2008
Creator: Zhou, Jian; Yuan, Feng & Liang, Zuo-Tang
System: The UNT Digital Library
Separation of Yeast Cells from MS2 Viruses Using Acoustic Radiation Force (open access)

Separation of Yeast Cells from MS2 Viruses Using Acoustic Radiation Force

We report a rapid and robust separation of Saccharomyces cerevisiae and MS2 bacteriophage using acoustic focusing in a microfluidic device. A piezoelectric transducer (PZT) generates acoustic standing waves in the microchannel. These standing waves induce acoustic radiation force fields that direct microparticles towards the nodes (i.e., pressure minima) or the anti-nodes (i.e., pressure maxima) of the standing waves depending on the relative compressidensity between the particle and the suspending liquid.[1] For particles larger than 2 {micro}m, the transverse velocities generated by these force fields enable continuous, high throughput separation. Extensive work in the last decade [2-4] has demonstrated acoustic focusing for manipulating microparticles or biological samples in microfluidic devices. This prior work has primarily focused on experimental realization of acoustic focusing without modeling or with limited one-dimensional modeling estimates. We recently developed a finite element modeling tool to predict the two-dimensional acoustic radiation force field perpendicular to the flow direction in microfluidic devices.[1] Here we compare results from this model with experimental parametric studies including variations of the PZT driving frequencies and voltages as well as various particle sizes and compressidensities. These experimental parametric studies also provide insight into the development of an adjustable 'virtual' pore-size filter as well as …
Date: March 27, 2008
Creator: Jung, B.; Fisher, K.; Ness, K.; Rose, K. A. & Mariella, R. P., Jr.
System: The UNT Digital Library
Isotopomer distributions in amino acids from a highly expressed protein as a proxy for those from total protein (open access)

Isotopomer distributions in amino acids from a highly expressed protein as a proxy for those from total protein

{sup 13}C-based metabolic flux analysis provides valuable information about bacterial physiology. Though many biological processes rely on the synergistic functions of microbial communities, study of individual organisms in a mixed culture using existing flux analysis methods is difficult. Isotopomer-based flux analysis typically relies on hydrolyzed amino acids from a homogeneous biomass. Thus metabolic flux analysis of a given organism in a mixed culture requires its separation from the mixed culture. Swift and efficient cell separation is difficult and a major hurdle for isotopomer-based flux analysis of mixed cultures. Here we demonstrate the use of a single highly-expressed protein to analyze the isotopomer distribution of amino acids from one organism. Using the model organism E. coli expressing a plasmid-borne, his-tagged Green Fluorescent Protein (GFP), we show that induction of GFP does not affect E. coli growth kinetics or the isotopomer distribution in nine key metabolites. Further, the isotopomer labeling patterns of amino acids derived from purified GFP and total cell protein are indistinguishable, indicating that amino acids from a purified protein can be used to infer metabolic fluxes of targeted organisms in a mixed culture. This study provides the foundation to extend isotopomer-based flux analysis to study metabolism of individual strains …
Date: June 27, 2008
Creator: Shaikh, Afshan; Shaikh, Afshan S.; Tang, Yinjie; Mukhopadhyay, Aindrila & Keasling, Jay D.
System: The UNT Digital Library
A THERMAL MODEL OF THE IMMOBILIZATION OF LOW-LEVEL RADIOACTIVE WASTE AS GROUT IN CONCRETE VAULTS (open access)

A THERMAL MODEL OF THE IMMOBILIZATION OF LOW-LEVEL RADIOACTIVE WASTE AS GROUT IN CONCRETE VAULTS

Salt solution will be mixed with cement and flyash/slag to form a grout which will be immobilized in above ground concrete vaults. The curing process is exothermic, and a transient thermal model of the pouring and curing process is herein described. A peak temperature limit of 85 C for the curing grout restricts the rate at which it can be poured into a vault. The model is used to optimize the pouring.
Date: October 27, 2008
Creator: Shadday, M
System: The UNT Digital Library
BIOTIGER, A NATURAL MICROBIAL PRODUCT FOR ENHANCED HYDROCARBON RECOVERY FROM OIL SANDS. (open access)

BIOTIGER, A NATURAL MICROBIAL PRODUCT FOR ENHANCED HYDROCARBON RECOVERY FROM OIL SANDS.

BioTiger{trademark} is a unique microbial consortia that resulted from over 8 years of extensive microbiology screening and characterization of samples collected from a century-old Polish waste lagoon. BioTiger{trademark} shows rapid and complete degradation of aliphatic and aromatic hydrocarbons, produces novel surfactants, is tolerant of both chemical and metal toxicity and shows good activity at temperature and pH extremes. Although originally developed and used by the U.S. Department of Energy for bioremediation of oil-contaminated soils, recent efforts have proven that BioTiger{trademark} can also be used to increase hydrocarbon recovery from oil sands. This enhanced ex situ oil recovery process utilizes BioTiger{trademark} to optimize bitumen separation. A floatation test protocol with oil sands from Ft. McMurray, Canada was used for the BioTiger{trademark} evaluation. A comparison of hot water extraction/floatation test of the oil sands performed with BioTiger{trademark} demonstrated a 50% improvement in separation as measured by gravimetric analysis in 4 h and a five-fold increase at 25 hr. Since BioTiger{trademark} performs well at high temperatures and process engineering can enhance and sustain metabolic activity, it can be applied to enhance recovery of hydrocarbons from oil sands or other complex recalcitrant matrices.
Date: May 27, 2008
Creator: Brigmon, R; Topher Berry, T; Whitney Jones, W & Charles Milliken, C
System: The UNT Digital Library
DEMONSTRATION OF EQUIVALENCY OF CANE AND SOFTWOOD BASED CELOTEX FOR MODEL 9975 SHIPPING PACKAGES (open access)

DEMONSTRATION OF EQUIVALENCY OF CANE AND SOFTWOOD BASED CELOTEX FOR MODEL 9975 SHIPPING PACKAGES

Cane-based Celotex{trademark} has been used extensively in various Department of Energy (DOE) packages as a thermal insulator and impact absorber. Cane-based Celotex{trademark} fiberboard was only manufactured by Knight-Celotex Fiberboard at their Marrero Plant in Louisiana. However, Knight-Celotex Fiberboard shut down their Marrero Plant in early 2007 due to impacts from hurricane Katrina and other economic factors. Therefore, cane-based Celotex{trademark} fiberboard is no longer available for use in the manufacture of new shipping packages requiring the material as a component. Current consolidation plans for the DOE Complex require the procurement of several thousand new Model 9975 shipping packages requiring cane-based Celotex{trademark} fiberboard. Therefore, an alternative to cane-based Celotex{trademark} fiberboard is needed. Knight-Celotex currently manufactures Celotex{trademark} fiberboard from other cellulosic materials, such as hardwood and softwood. A review of the relevant literature has shown that softwood-based Celotex{trademark} meets all parameters important to the Model 9975 shipping package.
Date: May 27, 2008
Creator: Watkins, R & Jason Varble, J
System: The UNT Digital Library
GLASS FORMULATION DEVELOPMENT AND TESTING FOR COLD CRUCIBLE INDUCTION MELTER (CCIM) ADVANCED REMEDIATION TECHNOLOGIES DEMONSTRATION PROJECT - 9208 (open access)

GLASS FORMULATION DEVELOPMENT AND TESTING FOR COLD CRUCIBLE INDUCTION MELTER (CCIM) ADVANCED REMEDIATION TECHNOLOGIES DEMONSTRATION PROJECT - 9208

Over the past few years, Cold Crucible Induction Melter (CCIM) demonstrations have been completed using SRS sludge batches 2, 3 and 4 (SB2, SB3 and SB4) simulant compositions. These campaigns demonstrated the ability of the CCIM to effectively produce quality glasses at high waste loadings. The current Advanced Remediation Technology (ART) Phase II-A Project is aimed at demonstrating the CCIM technology under representative DWPF flowsheet conditions and to demonstrate extended operations of the melter. A glass composition development effort was completed to identify and recommend a frit composition and sludge batch 4 (SB4) simulant waste loading target for subsequent ART-Phase II-A CCIM demonstration testing. Based on the results of the glass formulation testing, it was recommended that the Frit 503-R6 composition (B{sub 2}O{sub 3} = 14 wt %; Li{sub 2}O = 9 wt %; Na{sub 2}O = 3 wt %; and SiO{sub 2} = 74 wt %) be utilized for the demonstration. Furthermore, a waste loading of 46 wt % was recommended. The recommended frit and waste loading would produce a glass with acceptable durability with a liquidus temperature adequately below the 1250 C nominal CCIM operating temperature. This frit composition and waste loading was found to result in a …
Date: August 27, 2008
Creator: Marra, J; Amanda Billings, A; David Peeler, D; Michael Stone, M & Tommy Edwards, T
System: The UNT Digital Library
THE DOE OFFICE OF ENVIRONMENTAL MANAGEMENT INTERNATIONAL COOPERATIVE PROGRAM: CURRENT STATUS AND PLANS FOR EXPANSION (open access)

THE DOE OFFICE OF ENVIRONMENTAL MANAGEMENT INTERNATIONAL COOPERATIVE PROGRAM: CURRENT STATUS AND PLANS FOR EXPANSION

None
Date: August 27, 2008
Creator: Marra, J; Kevin Fox, K; David Peeler, D; Michael02 Smith, M; Tim Jannik, T & Eduardo Farfan, E
System: The UNT Digital Library
Combined low-temperature scanning tunneling/atomic force microscope for atomic resolution imaging and site-specific force spectroscopy (open access)

Combined low-temperature scanning tunneling/atomic force microscope for atomic resolution imaging and site-specific force spectroscopy

The authors present the design and first results of a low-temperature, ultrahigh vacuum scanning probe microscope enabling atomic resolution imaging in both scanning tunneling microscopy (STM) and noncontact atomic force microscopy (NC-AFM) modes. A tuning-fork-based sensor provides flexibility in selecting probe tip materials, which can be either metallic or nonmetallic. When choosing a conducting tip and sample, simultaneous STM/NC-AFM data acquisition is possible. Noticeable characteristics that distinguish this setup from similar systems providing simultaneous STM/NC-AFM capabilities are its combination of relative compactness (on-top bath cryostat needs no pit), in situ exchange of tip and sample at low temperatures, short turnaround times, modest helium consumption, and unrestricted access from dedicated flanges. The latter permits not only the optical surveillance of the tip during approach but also the direct deposition of molecules or atoms on either tip or sample while they remain cold. Atomic corrugations as low as 1 pm could successfully be resolved. In addition, lateral drifts rates of below 15 pm/h allow long-term data acquisition series and the recording of site-specific spectroscopy maps. Results obtained on Cu(111) and graphite illustrate the microscope's performance.
Date: February 27, 2008
Creator: Schwarz, Udo; Albers, Boris J.; Liebmann, Marcus; Schwendemann, Todd C.; Baykara, Mehmet Z.; Heyde, Markus et al.
System: The UNT Digital Library
Turbulence-Flame Interactions in Type Ia Supernovae (open access)

Turbulence-Flame Interactions in Type Ia Supernovae

The large range of time and length scales involved in type Ia supernovae (SN Ia) requires the use of flame models. As a prelude to exploring various options for flame models, we consider, in this paper, high-resolution three-dimensional simulations of the small-scale dynamics of nuclear flames in the supernova environment in which the details of the flame structure are fully resolved. The range of densities examined, 1 to 8 x 107 g cm-3, spans the transition from the laminar flamelet regime to the distributed burning regime where small scale turbulence disrupts the flame. The use of a low Mach number algorithm facilitates the accurate resolution of the thermal structure of the flame and the inviscid turbulent kinetic energy cascade, while implicitly incorporating kinetic energy dissipation at the grid-scale cutoff. For an assumed background of isotropic Kolmogorov turbulence with an energy characteristic of SN Ia, we find a transition density between 1 and 3 x 107 g cm-3 where the nature of the burning changes ualitatively. By 1 x 107 g cm-3, energy diffusion by conduction and radiation is exceeded, on the flame scale, by turbulent advection. As a result, the effective Lewis Number approaches unity. That is, the flame resembles …
Date: May 27, 2008
Creator: Aspden, Andrew J.; Bell, John B.; Day, Marc S.; Woosley, Stan E. & Zingale, Mike
System: The UNT Digital Library
Studies of Potential Inhibitors of Sodium Aluminosilicate Scales in High-Level Waste Evaporation (open access)

Studies of Potential Inhibitors of Sodium Aluminosilicate Scales in High-Level Waste Evaporation

The Savannah River Site (SRS) has 49 underground storage tanks used to store High Level Waste (HLW). The tank space in these tanks must be managed to support the continued operation of key facilities. The reduction of the tank volumes in these tanks are accomplished through the use of three atmospheric pressure HLW evaporators. For a decade, evaporation of highly alkaline HLW containing aluminum and silicates has produced sodium aluminosilicate scales causing both operation and criticality hazards in the 2H Evaporator System. Segregation of aluminum-rich wastes from silicate-rich wastes minimizes the amount of scale produced and reduces cleaning expenses, but does not eliminate the scaling nor increases operation flexibility in waste process. Similar issues have affected the aluminum refining industry for many decades. Over the past several years, successful commercial products have been identified to eliminate aluminosilicate fouling in the aluminum industry, but have not been utilized in a nuclear environment. Laboratory quantities of three proprietary aluminosilicate scale inhibitors have been produced and been shown to prevent formation of scales. SRNL has been actively testing these potential inhibitors to examine their radiation stability, radiolytic degradation behaviors, and downstream impacts to determine their viability within the HLW system. One of the …
Date: February 27, 2008
Creator: Wilmarth, W. R.; Oji, L. N.; Fellinger, T. L.; Hobbs, D. T. & Badheka, N. P.
System: The UNT Digital Library
Bin-Hash Indexing: A Parallel Method for Fast Query Processing (open access)

Bin-Hash Indexing: A Parallel Method for Fast Query Processing

This paper presents a new parallel indexing data structure for answering queries. The index, called Bin-Hash, offers extremely high levels of concurrency, and is therefore well-suited for the emerging commodity of parallel processors, such as multi-cores, cell processors, and general purpose graphics processing units (GPU). The Bin-Hash approach first bins the base data, and then partitions and separately stores the values in each bin as a perfect spatial hash table. To answer a query, we first determine whether or not a record satisfies the query conditions based on the bin boundaries. For the bins with records that can not be resolved, we examine the spatial hash tables. The procedures for examining the bin numbers and the spatial hash tables offer the maximum possible level of concurrency; all records are able to be evaluated by our procedure independently in parallel. Additionally, our Bin-Hash procedures access much smaller amounts of data than similar parallel methods, such as the projection index. This smaller data footprint is critical for certain parallel processors, like GPUs, where memory resources are limited. To demonstrate the effectiveness of Bin-Hash, we implement it on a GPU using the data-parallel programming language CUDA. The concurrency offered by the Bin-Hash index …
Date: June 27, 2008
Creator: Bethel, Edward W.; Gosink, Luke J.; Wu, Kesheng; Bethel, Edward Wes; Owens, John D. & Joy, Kenneth I.
System: The UNT Digital Library
Least Squares Magnetic-Field Optimization for Portable Nuclear Magnetic Resonance Magnet Design (open access)

Least Squares Magnetic-Field Optimization for Portable Nuclear Magnetic Resonance Magnet Design

Single-sided and mobile nuclear magnetic resonance (NMR) sensors have the advantages of portability, low cost, and low power consumption compared to conventional high-field NMR and magnetic resonance imaging (MRI) systems. We present fast, flexible, and easy-to-implement target field algorithms for mobile NMR and MRI magnet design. The optimization finds a global optimum ina cost function that minimizes the error in the target magnetic field in the sense of least squares. When the technique is tested on a ring array of permanent-magnet elements, the solution matches the classical dipole Halbach solution. For a single-sided handheld NMR sensor, the algorithm yields a 640 G field homogeneous to 16 100 ppm across a 1.9 cc volume located 1.5 cm above the top of the magnets and homogeneous to 32 200 ppm over a 7.6 cc volume. This regime is adequate for MRI applications. We demonstrate that the homogeneous region can be continuously moved away from the sensor by rotating magnet rod elements, opening the way for NMR sensors with adjustable"sensitive volumes."
Date: March 27, 2008
Creator: Paulsen, Jeffrey L; Franck, John; Demas, Vasiliki & Bouchard, Louis-S.
System: The UNT Digital Library
SHIELDING ANALYSIS FOR X-RAY SOURCES GENERATED IN TARGET CHAMBER OF THE NATIONAL IGNITION FACILITY (open access)

SHIELDING ANALYSIS FOR X-RAY SOURCES GENERATED IN TARGET CHAMBER OF THE NATIONAL IGNITION FACILITY

Prompt doses from x-rays generated as result of laser beam interaction with target material are calculated at different locations inside the National Ignition Facility (NIF). The maximum dose outside a Target Chamber diagnostic port is {approx} 1 rem for a shot utilizing the 192 laser beams and 1.8 MJ of laser energy. The dose during a single bundle shot (8 laser beams) drops to {approx} 40 mrem. Doses calculated outside the Target Bay doors and inside the Switchyards (except for the 17 ft.-6 in. level) range from a fraction of mrem to about 11 mrem for 192 beams, and scales down proportionally with smaller number of beams. At the 17ft.-6 in. level, two diagnostic ports are directly facing two of the Target Bay doors and the maximum doses outside the doors are 51 and 15.5 mrem, respectively. Shielding each of the two Target Bay doors with 1/4 in. Pb reduces the dose by factor of fifty. One or two bundle shots (8 to 16 laser beams) present a small hazard to personnel in the Switchyards.
Date: March 27, 2008
Creator: Khater, H Y; Brereton, S J & Singh, M S
System: The UNT Digital Library
Technology of the LSST Focal Plane (open access)

Technology of the LSST Focal Plane

None
Date: February 27, 2008
Creator: O'Connor, P.; Radeka, V.; Takacs, P.; Geary, J.; Gilmore, K.; Oliver, J. et al.
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop: Understanding QGP through Spectral Functions and Euclidean Correlators (Volume 89) (open access)

Proceedings of RIKEN BNL Research Center Workshop: Understanding QGP through Spectral Functions and Euclidean Correlators (Volume 89)

In the past two decades, one of the most important goals of the nuclear physics community has been the production and characterization of the new state of matter--Quark-Gluon Plasma (QGP). Understanding how properties of hadrons change in medium, particularly, the bound state of a very heavy quark and its antiquark, known as quarkonium, as well as determining the transport coefficients is crucial for identifying the properties of QGP and for the understanding of the experimental data from RHIC. On April 23rd, more than sixty physicists from twenty-seven institutions gathered for this three-day topical workshop held at BNL to discuss how to understand the properties of the new state of matter obtained in ultra-relativistic heavy ion collisions (particularly at RHIC-BNL) through spectral functions. In-medium properties of the different particle species and the transport properties of the medium are encoded in spectral functions. The former could yield important signatures of deconfinement and chiral symmetry restoration at high temperatures and densities, while the later are crucial for the understanding of the dynamics of ultra-relativistic heavy ion collisions. Participants at the workshop are experts in various areas of spectral function studies. The workshop encouraged direct exchange of scientific information among experts, as well as …
Date: June 27, 2008
Creator: Mocsy, A. & Petreczky, P.
System: The UNT Digital Library
Coordination of Retail Demand Response with Midwest ISO Markets (open access)

Coordination of Retail Demand Response with Midwest ISO Markets

The Organization of Midwest ISO States (OMS) launched the Midwest Demand Resource Initiative (MWDRI) in 2007 to identify barriers to deploying demand response (DR) resources in the Midwest Independent System Operator (MISO) region and develop policies to overcome them. The MWDRI stakeholders decided that a useful initial activity would be to develop more detailed information on existing retail DR programs and dynamic pricing tariffs, program rules, and utility operating practices. This additional detail could then be used to assess any"seams issues" affecting coordination and integration of retail DR resources with MISO's wholesale markets. Working with state regulatory agencies, we conducted a detailed survey of existing DR programs, dynamic pricing tariffs, and their features in MISO states. Utilities were asked to provide information on advance notice requirements to customers, operational triggers used to call events (e.g. system emergencies, market conditions, local emergencies), use of these DR resources to meet planning reserves requirements, DR resource availability (e.g., seasonal, annual), participant incentive structures, and monitoring and verification (M&V) protocols. This report describes the results of this comprehensive survey and discusses policy implications for integrating legacy retail DR programs and dynamic pricing tariffs into organized wholesale markets. Survey responses from 37 MISO members and …
Date: May 27, 2008
Creator: Bharvirkar, Ranjit; Bharvirkar, Ranjit; Goldman, Charles; Heffner, Grayson & Sedano, Richard
System: The UNT Digital Library
MECHANISMS OF PHASE FORMATION IN THE VITRIFICATION OF HIGH-FERROUS SAVANNAH RIVER SITE SB2 HLW SLUDGE SURROGATE - 9300 (open access)

MECHANISMS OF PHASE FORMATION IN THE VITRIFICATION OF HIGH-FERROUS SAVANNAH RIVER SITE SB2 HLW SLUDGE SURROGATE - 9300

Phase formation mechanisms associated with the vitrification of high-ferrous Savannah River Site (SRS) Sludge Batch 2 (SB2) high level waste surrogate were studied by infrared spectroscopy (IRS) and X-ray diffraction (XRD). Two mixtures at 50 wt% waste loading with commercially available Frit 320 (Li{sub 2}O - 8 wt %, B{sub 2}O{sub 3} - 8 wt %, Na{sub 2}O - 12 wt %, SiO{sub 2} - 72 wt %) and batch chemicals (LiOH {center_dot} H{sub 2}O, H{sub 3}BO{sub 3}, NaNO{sub 3}, SiO{sub 2}) to represent the frit formulation were prepared as slurries with a water content of {approx}50 wt%. The mixtures were air-dried at a temperature of 115 C and heat-treated at 500, 700, 900, 1000, 1100, 1200, and 1300 C for 1 hr at each temperature. Infrared spectra and XRD patterns of the products produced at each temperature were recorded. In both mixtures prepared using frit and batch chemicals to represent the frit, phase formation reactions were completed within the temperature range between 900 and 1000 C. However, residual quartz was still present in glass produced from the mixture with batch chemicals even at 1100 C. Although, the phase composition and structure of the glassy products obtained from both mixtures …
Date: August 27, 2008
Creator: Marra, J
System: The UNT Digital Library
HYDROGEN EFFECTS ON THE BURST PROPERTIES OF TYPE 304L STAINLESS STEEL FLAWED VESSELS (open access)

HYDROGEN EFFECTS ON THE BURST PROPERTIES OF TYPE 304L STAINLESS STEEL FLAWED VESSELS

The effect of hydrogen on the burst properties Type 304L stainless steel vessels was investigated. The purpose of the study was to compare the burst properties of hydrogen-exposed stainless steel vessels burst with different media: water, helium gas, or deuterium gas. A second purpose of the tests was to provide data for the development of a predictive finite-element model. The burst tests were conducted on hydrogen-exposed and unexposed axially-flawed cylindrical vessels. The results indicate that samples burst pneumatically had lower volume ductility than those tested hydraulically. Deuterium gas tests had slightly lower ductility than helium gas tests. Burst pressures were not affected by burst media. Hydrogen-charged samples had lower volume ductility and slightly higher burst pressures than uncharged samples. Samples burst with deuterium gas fractured by quasi-cleavage near the inside wall. The results of the tests were used to improve a previously developed predictive finite-element model. The results show that predicting burst behavior requires as a material input the effect of hydrogen on the plastic strain to fracture from tensile tests. The burst test model shows that a reduction in the plastic strain to fracture of the material will result in lower volume ductility without a reduction in burst pressure …
Date: March 27, 2008
Creator: Morgan, M; Monica Hall, M; Ps Lam, P & Dean Thompson, D
System: The UNT Digital Library