Exclusive e+e-, di-photon and di-jet production at the Tevatron (open access)

Exclusive e+e-, di-photon and di-jet production at the Tevatron

Results from studies on exclusive production of electron-position pair, di-photon, and dijet production at CDF in proton-antiproton collisions at the Fermilab Tevatron are presented. THe first observation and cross section measurements of exclusive e{sup +}e{sup -} and di-jet production in hadron-hadron collisions are emphasized.
Date: May 1, 2007
Creator: Terashi, Koji
Object Type: Article
System: The UNT Digital Library
Highly Enriched uranium Metal Spheres Surrounded by Various Reflectors (open access)

Highly Enriched uranium Metal Spheres Surrounded by Various Reflectors

A series of experiments was performed at the Los Alamos critical assembly facility in the early 1950s to determine the critical mass of highly enriched uranium spheres surrounded by thin reflectors of various materials. The objective of these experiments was to obtain a precision graph of the critical mass of highly enriched uranium metal as a function of reflector thickness and to generate transport cross sections for the reflector material. Thirteen configurations are described and evaluated under ICSBEP identifier, HEU-MET-FAST-085; two with 1.98-inch-thick and 4.158-inch-thick copper reflectors, two with 2- and 4-inch-thick cast iron reflectors, one with a 1.945-inch-thick nickel reflector, two with 1.88- and 2.02-inch-thick nickel-copper-zinc alloy reflectors, one with a 1.81-inch-thick thorium reflector, two with 2-inch-thick and 4-inch-thick tungsten alloy reflectors, two with 2-inch-thick and 4.075-inch-thick zinc reflectors, and one with a 2-inch-thick tungsten alloy reflector surrounded by a 2-inch-thick cast iron reflector. All configurations were slightly subcritical with measured multiplications ranging from 20 to 162. Analyses were performed in which uncertainty associated with six different parameters was evaluated; namely, extrapolation to uranium critical mass, uranium density, 235U enrichment, reflector density, reflector thickness, and reflector impurities were considered. Uncertainty in cast-iron alloying elements was also considered when appropriate. …
Date: May 1, 2007
Creator: Feener, Jessica; Briggs, J. Blair & Montierth, Leland
Object Type: Article
System: The UNT Digital Library
Searches for non-standard-model Higgs bosons at the Tevatron (open access)

Searches for non-standard-model Higgs bosons at the Tevatron

Search for non-Standard-Model Higgs bosons is one of the major goals of the ongoing Fermilab Tevatron run. Large data sets accumulated by the CDF and D{O} experiments break new grounds in sensitivity. We review recent Tevatron results on searches for Higgs bosons in Minimal Supersymmetric Model in the multi b-jet and {tau}{tau} final states, as well as a search for fermiophobic Higgs in the multiphoton final state.
Date: May 1, 2007
Creator: Landsberg, Greg L. & U., /Brown
Object Type: Article
System: The UNT Digital Library
Drug Retention Times (open access)

Drug Retention Times

The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.
Date: May 1, 2007
Creator: Studies, Center for Human Reliability
Object Type: Report
System: The UNT Digital Library
OFF-GAS MERCURY CONTROL USING SULFUR-IMPREGNATED ACTIVATED CARBON – TEST RESULTS (open access)

OFF-GAS MERCURY CONTROL USING SULFUR-IMPREGNATED ACTIVATED CARBON – TEST RESULTS

Several laboratory and pilot-scale tests since the year 2000 have included demonstrations of off-gas mercury control using fixed bed, sulfur-impregnated activated carbon. These demonstrations have included operation of carbon beds with gas streams containing a wide range of mercury and other gas species concentrations representing off-gas from several U.S. Department of Energy (DOE) mixed waste treatment processes including electrical resistance heated (joule-heated) glass melters, fluidized bed calciners, and fluidized bed steam reformers. Surrogates of various DOE mixed waste streams (or surrogates of offgas from DOE mixed waste streams) including INL “sodium bearing waste” (SBW), liquid “low activity waste” (LAW) from the Pacific Northwest National Laboratory, and liquid waste from Savannah River National Laboratory (“Tank 48H waste”) have been tested. Test results demonstrate mercury control efficiencies up to 99.999%, high enough to comply with the Hazardous Waste (HWC) Combustor Maximum Achievable Control Technology (MACT) standards even when the uncontrolled off-gas mercury concentrations exceed 400,000 ug/dscm (at 7% O2), and confirm carbon bed design parameters for such high efficiencies. Results of several different pilot-scale and engineering-scale test programs performed over several years are presented and compared.
Date: May 1, 2007
Creator: Soelberg, Nick
Object Type: Article
System: The UNT Digital Library
Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements: Industrial Technologies Program (ITP) Pumping Systems Tip Sheet #12 (open access)

Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements: Industrial Technologies Program (ITP) Pumping Systems Tip Sheet #12

One in a series of tip sheets to help manufacturers optimize their industrial pumping systems
Date: May 1, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Technical Basis Document: A Statistical Basis for Interpreting Urinary Excretion of Plutonium Based on Accelerator Mass Spectrometry (AMS) for Selected Atoll Populations in the Marshall Islands (open access)

Technical Basis Document: A Statistical Basis for Interpreting Urinary Excretion of Plutonium Based on Accelerator Mass Spectrometry (AMS) for Selected Atoll Populations in the Marshall Islands

We have developed refined statistical and modeling techniques to assess low-level uptake and urinary excretion of plutonium from different population group in the northern Marshall Islands. Urinary excretion rates of plutonium from the resident population on Enewetak Atoll and from resettlement workers living on Rongelap Atoll range from <1 to 8 {micro}Bq per day and are well below action levels established under the latest Department regulation 10 CFR 835 in the United States for in vitro bioassay monitoring of {sup 239}Pu. However, our statistical analyses show that urinary excretion of plutonium-239 ({sup 239}Pu) from both cohort groups is significantly positively associated with volunteer age, especially for the resident population living on Enewetak Atoll. Urinary excretion of {sup 239}Pu from the Enewetak cohort was also found to be positively associated with estimates of cumulative exposure to worldwide fallout. Consequently, the age-related trends in urinary excretion of plutonium from Marshallese populations can be described by either a long-term component from residual systemic burdens acquired from previous exposures to worldwide fallout or a prompt (and eventual long-term) component acquired from low-level systemic intakes of plutonium associated with resettlement of the northern Marshall Islands, or some combination of both.
Date: May 1, 2007
Creator: Bogen, K; Hamilton, T F; Brown, T A; Martinelli, R E; Marchetti, A A; Kehl, S R et al.
Object Type: Report
System: The UNT Digital Library
Contamination and solid state welds. (open access)

Contamination and solid state welds.

Since sensitivity to contamination is one of the verities of solid state joining, there is a need for assessing contamination of the part(s) to be joined, preferably nondestructively while it can be remedied. As the surfaces that are joined in pinch welds are inaccessible and thus provide a greater challenge, most of the discussion is of the search for the origin and effect of contamination on pinch welding and ways to detect and mitigate it. An example of contamination and the investigation and remediation of such a system is presented. Suggestions are made for techniques for nondestructive evaluation of contamination of surfaces for other solid state welds as well as for pinch welds. Surfaces that have good visual access are amenable to inspection by diffuse reflection infrared Fourier transform (DRIFT) spectroscopy. Although other techniques are useful for specific classes of contaminants (such as hydrocarbons), DRIFT can be used most classes of contaminants. Surfaces such as the interior of open tubes or stems that are to be pinch welded can be inspected using infrared reflection spectroscopy. It must be demonstrated whether or not this tool can detect graphite based contamination, which has been seen in stems. For tubes with one closed …
Date: May 1, 2007
Creator: Mills, Bernice E.
Object Type: Report
System: The UNT Digital Library
Tritiated Water Interaction with Stainless Steel (open access)

Tritiated Water Interaction with Stainless Steel

Experiments conducted to study tritium permeation of stainless steel at ambient and elevated temperatures revealed that HT converts relatively quickly to HTO. Further, the HTO partial pressure contributes essentially equally with elemental tritium gas in driving permeation through the stainless steel. Such permeation appears to be due to dissociation of the water molecule on the hot stainless steel surface. There is an equilibrium concentration of HTO vapor above adsorbed gas on the walls of the experimental apparatus evident from freezing transients. The uptake process of tritium from the carrier gas involves both surface adsorption and isotopic exchange with surface bound water.
Date: May 1, 2007
Creator: Longhurst, Glen R.
Object Type: Report
System: The UNT Digital Library
Toward a 20% Wind Electricity Supply in the United States: Preprint (open access)

Toward a 20% Wind Electricity Supply in the United States: Preprint

Since the U.S. Department of Energy (DOE) initiated the Wind Powering America (WPA) program in 1999, installed wind power capacity in the United States has increased from 2,500 MW to more than 11,000 MW. In 1999, only four states had more than 100 MW of installed wind capacity; now 16 states have more than 100 MW installed. In addition to WPA's efforts to increase deployment, the American Wind Energy Association (AWEA) is building a network of support across the country. In July 2005, AWEA launched the Wind Energy Works! Coalition, which is comprised of more than 70 organizations. In February 2006, the wind deployment vision was enhanced by President George W. Bush's Advanced Energy Initiative, which refers to a wind energy contribution of up to 20% of the electricity consumption of the United States. A 20% electricity contribution over the next 20 to 25 years represents 300 to 350 gigawatts (GW) of electricity. This paper provides a background of wind energy deployment in the United States and a history of the U.S. DOE's WPA program, as well as the program's approach to increasing deployment through removal of institutional and informational barriers to a 20% wind electricity future.
Date: May 1, 2007
Creator: Flowers, L. & Dougherty, P.
Object Type: Article
System: The UNT Digital Library
Highly Enriched Uranium Metal Annuli and Cylinders with Polyethylene Reflectors and/or Internal Polyethylene Moderator (open access)

Highly Enriched Uranium Metal Annuli and Cylinders with Polyethylene Reflectors and/or Internal Polyethylene Moderator

A variety of critical experiments were constructed of enriched uranium metal during the 1960s and 1970s at the Oak Ridge Critical Experiments Facility in support of criticality safety operations at the Y-12 Plant. The purposes of these experiments included the evaluation of storage, casting, and handling limits for the Y-12 Plant and providing data for verification of calculation methods and cross-sections for nuclear criticality safety applications. These included solid cylinders of various diameters, annuli of various inner and outer diameters, two and three interacting cylinders of various diameters, and graphite and polyethylene reflected cylinders and annuli. Of the hundreds of delayed critical experiments, experiments of uranium metal annuli with and without polyethylene reflectors and with the central void region either empty or filled with polyethylene were evaluated under ICSBEP Identifier HEU-MET-FAST-076. The outer diameter of the uranium annuli varied from 9 to 15 inches in two-inch increments. In addition, there were uranium metal cylinders with diameters varying from 7 to 15 inches with complete reflection and reflection on one flat surface to simulate floor reflection. Most of the experiments were performed between February 1964 and April 1964. Five partially reflected (reflected on the top only) experiments were assembled in November …
Date: May 1, 2007
Creator: Sumner, Tyler; Briggs, J. Blair & Montierth, Leland
Object Type: Article
System: The UNT Digital Library
Highly Enriched Uranium Metal Cylinders Surrounded by Various Reflector Materials (open access)

Highly Enriched Uranium Metal Cylinders Surrounded by Various Reflector Materials

A series of experiments was performed at Los Alamos Scientific Laboratory in 1958 to determine critical masses of cylinders of Oralloy (Oy) reflected by a number of materials. The experiments were all performed on the Comet Universal Critical Assembly Machine, and consisted of discs of highly enriched uranium (93.3 wt.% 235U) reflected by half-inch and one-inch-thick cylindrical shells of various reflector materials. The experiments were performed by members of Group N-2, particularly K. W. Gallup, G. E. Hansen, H. C. Paxton, and R. H. White. This experiment was intended to ascertain critical masses for criticality safety purposes, as well as to compare neutron transport cross sections to those obtained from danger coefficient measurements with the Topsy Oralloy-Tuballoy reflected and Godiva unreflected critical assemblies. The reflector materials examined in this series of experiments are as follows: magnesium, titanium, aluminum, graphite, mild steel, nickel, copper, cobalt, molybdenum, natural uranium, tungsten, beryllium, aluminum oxide, molybdenum carbide, and polythene (polyethylene). Also included are two special configurations of composite beryllium and iron reflectors. Analyses were performed in which uncertainty associated with six different parameters was evaluated; namely, extrapolation to the uranium critical mass, uranium density, 235U enrichment, reflector density, reflector thickness, and reflector impurities. In …
Date: May 1, 2007
Creator: Jones, Bernard; Briggs, J. Blair & Monteirth, Leland
Object Type: Article
System: The UNT Digital Library
Flexible Fuel Vehicles: Providing a Renewable Fuel Choice (open access)

Flexible Fuel Vehicles: Providing a Renewable Fuel Choice

This Clean Cities Program fact sheet describes aspects of flexible fuel vehicles such as use of E85, special features, benefits of use, costs, and fueling locations. It discusses performance and lists additional resources.
Date: May 1, 2007
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Arsenic pilot plant operation and results - Socorro Springs, New Mexico - phase 1. (open access)

Arsenic pilot plant operation and results - Socorro Springs, New Mexico - phase 1.

Sandia National Laboratories (SNL) is conducting pilot scale evaluations of the performance and cost of innovative water treatment technologies aimed at meeting the recently revised arsenic maximum contaminant level (MCL) for drinking water. The standard of 10 {micro}g/L (10 ppb) is effective as of January 2006. The first pilot tests have been conducted in New Mexico where over 90 sites that exceed the new MCL have been identified by the New Mexico Environment Department. The pilot test described in this report was conducted in Socorro New Mexico between January 2005 and July 2005. The pilot demonstration is a project of the Arsenic Water Technology Partnership program, a partnership between the American Water Works Association Research Foundation (AwwaRF), SNL and WERC (A Consortium for Environmental Education and Technology Development). The Sandia National Laboratories pilot demonstration at the Socorro Springs site obtained arsenic removal performance data for five different adsorptive media under constant ambient flow conditions. Well water at Socorro Springs has approximately 42 ppb arsenic in the oxidized (arsenate-As(V)) redox state with moderate amounts of silica, low concentrations of iron and manganese and a slightly alkaline pH (8). The study provides estimates of the capacity (bed volumes until breakthrough at 10 …
Date: May 1, 2007
Creator: Aragon, Malynda Jo; Everett, Randy L.; Siegel, Malcolm Dean; Kottenstette, Richard Joseph; Holub, William E. Jr; Wright, Jeremy B. et al.
Object Type: Report
System: The UNT Digital Library
Nonlinearly-constrained optimization using asynchronous parallel generating set search. (open access)

Nonlinearly-constrained optimization using asynchronous parallel generating set search.

Many optimization problems in computational science and engineering (CS&E) are characterized by expensive objective and/or constraint function evaluations paired with a lack of derivative information. Direct search methods such as generating set search (GSS) are well understood and efficient for derivative-free optimization of unconstrained and linearly-constrained problems. This paper addresses the more difficult problem of general nonlinear programming where derivatives for objective or constraint functions are unavailable, which is the case for many CS&E applications. We focus on penalty methods that use GSS to solve the linearly-constrained problems, comparing different penalty functions. A classical choice for penalizing constraint violations is {ell}{sub 2}{sup 2}, the squared {ell}{sub 2} norm, which has advantages for derivative-based optimization methods. In our numerical tests, however, we show that exact penalty functions based on the {ell}{sub 1}, {ell}{sub 2}, and {ell}{sub {infinity}} norms converge to good approximate solutions more quickly and thus are attractive alternatives. Unfortunately, exact penalty functions are discontinuous and consequently introduce theoretical problems that degrade the final solution accuracy, so we also consider smoothed variants. Smoothed-exact penalty functions are theoretically attractive because they retain the differentiability of the original problem. Numerically, they are a compromise between exact and {ell}{sub 2}{sup 2}, i.e., they …
Date: May 1, 2007
Creator: Griffin, Joshua D. & Kolda, Tamara Gibson
Object Type: Report
System: The UNT Digital Library
Qe Measurements of a Nb-Pb Photoinjector. (open access)

Qe Measurements of a Nb-Pb Photoinjector.

We report recent progress in the development of a hybrid lead niobium superconducting RF (SRF) photoinjector. The goal of this effort is to produce an injector with the SRF properties of a niobium cavity along with the superior quantum efficiency (QE) of a lead photocathode. A prototype hybrid injector, consisting of an all-niobium cavity arc-deposited with lead in the cathode region, has been constructed. We present the results of QE measurements on this cavity under RF field, and an arc-deposited cathode under DC bias at cryogenic temperatures.
Date: May 1, 2007
Creator: Smedley, J.; Rao, T.; Warren, J.; Kneisel, P.; Sekutowicz, J.; Iversen, J. et al.
Object Type: Article
System: The UNT Digital Library
Top quark mass measurements at the Tevatron and the standard model fits (open access)

Top quark mass measurements at the Tevatron and the standard model fits

New measurements of the top quark mass from the Tevatron are presented. Combined with previous results, they yield a preliminary new world average of m{sub top} = 170.9 {+-} 1.1(stat) {+-} 1.5(syst)GeV/c{sup 2} and impose new constraints on the mass of the Higgs boson.
Date: May 1, 2007
Creator: Wang, Michael H.L.S.
Object Type: Article
System: The UNT Digital Library
An ultrafast x-ray detector system at an elliptically polarizingundulator beamline (open access)

An ultrafast x-ray detector system at an elliptically polarizingundulator beamline

An ultrafast x-ray detector system is under development atLawrence Berkeley National Laboratory (LBNL) for application primarily tostudyies of ultrafast magnetization dynamics. The system consists of a fslaser, an x-ray streak camera and an ellipitically polarization undulator(EPU) beamline. Polarized x-rays from an EPU can be used to measure x-raymagnetic circular dichroism (XMCD) of a sample. XMCD has the uniqueability to independently measure orbit and spin magnetization withsub-monolayer sensitivity and element specificity. The streak camera hassimultaneously a sub-picosecond temporal resolution and a high spatialresolution. The combination of the streak camera and EPU allows us tostudy the transfer of angular momentum from spin to orbit to the latticein the sample on an ultrafast time scale. We describe here theperformance of the ultrafast detector, the laser and the x-raysynchronization system. The observation of the demagnetization process ofdifferent samples demonstrates the ability of the apparatus.
Date: May 1, 2007
Creator: Feng, J.; Comin, A.; Bartelt, A. F.; Shin, H. J.; Nasiatka, J. R.; Padmore, H. A. et al.
Object Type: Article
System: The UNT Digital Library
Z gamma production and limits on anomalous Z Z gamma and Z gamma gamma couplings in panti-p collisions at s**(1/2) = 1.96- TeV (open access)

Z gamma production and limits on anomalous Z Z gamma and Z gamma gamma couplings in panti-p collisions at s**(1/2) = 1.96- TeV

None
Date: May 1, 2007
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
Object Type: Article
System: The UNT Digital Library
Carbon Dioxide Separation with Supported Ionic Liquid Membranes (open access)

Carbon Dioxide Separation with Supported Ionic Liquid Membranes

A practical form of CO2 capture at water-gas shift conditions in the IGCC process could serve the dual function of producing a pure CO2 stream for sequestration and forcing the equilibrium-limited shift reaction to completion enriching the stream in H2. The shift temperatures, ranging from the low temperature shift condition of 260°C to the gasification condition of 900°C, limit capture options by diminishing associative interactions which favor removal of CO2 from the gas stream. Certain sorption interactions, such as carbonate formation, remain available but generally involve exceptionally high sorbent regeneration energies that contribute heavily to parasitic power losses. Carbon dioxide selective membranes need only establish an equilibrium between the gas phase and sorption states in order to transport CO2, giving them a potential energetic advantage over other technologies. Supported liquid membranes take advantage of high, liquid phase diffusivities and a solution diffusion mechanism similar to that observed in polymeric membranes to achieve superior permeabilities and selectivites. The primary shortcoming of the supported liquid membranes demonstrated in past research has been the lack of stability caused by volatilization of the transport liquid. Ionic liquids, which possess high CO2 solubility relative to light gases such as H2, are excellent candidates for this …
Date: May 1, 2007
Creator: Luebke, David R.; Ilconich, Jeffery B.; Myers, Christina R. & Pennline, Henry W.
Object Type: Article
System: The UNT Digital Library
Towards the Integration of APECS and VE-Suite for Virtual Power Plant Co-Simulation (open access)

Towards the Integration of APECS and VE-Suite for Virtual Power Plant Co-Simulation

Process modeling and simulation tools are widely used for the design and operation of advanced power generation systems. These tools enable engineers to solve the critical process systems engineering problems that arise throughout the lifecycle of a power plant, such as designing a new process, troubleshooting a process unit or optimizing operations of the full process. To analyze the impact of complex thermal and fluid flow phenomena on overall power plant performance, the Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) has developed the Advanced Process Engineering Co-Simulator (APECS). The APECS system is an integrated software suite that combines process simulation (e.g., Aspen Plus) and high-fidelity equipment simulations such as those based on computational fluid dynamics (CFD), together with advanced analysis capabilities including case studies, sensitivity analysis, stochastic simulation for risk/uncertainty analysis, and multi-objective optimization. In this paper we discuss the initial phases of the integration of the APECS system with the immersive and interactive virtual engineering software, VE-Suite, developed at Iowa State University and Ames Laboratory. VE-Suite uses the ActiveX (OLE Automation) controls in the Aspen Plus process simulator wrapped by the CASI library developed by Reaction Engineering International to run process/CFD co-simulations and query for results. This …
Date: May 1, 2007
Creator: Zitney, S. E.; McCorkle, D. (Iowa State University, Ames, IA); Yang, C. (Reaction Engineering International, Salt Lake City, UT); Jordan, T.; Swensen, D. (Reaction Engineering International, Salt Lake City, UT) & Bryden, M. (Iowa State University, Ames, IA)
Object Type: Article
System: The UNT Digital Library
ACRF Instrumentation Status: New, Current, and Future (open access)

ACRF Instrumentation Status: New, Current, and Future

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Program Climate Research Facility instrumentation status. The report is divided into four sections: (1) new instrumentation in the process of being acquired and deployed, (2) existing instrumentation and progress on improvements or upgrades, (3) proposed future instrumentation, and (4) Small Business Innovation Research instrument development.
Date: May 1, 2007
Creator: Liljegren, J. C.
Object Type: Report
System: The UNT Digital Library
Influence of Shrinkage and Swelling Properties of Coal on Geologic Sequestration of Carbon Dioxide (open access)

Influence of Shrinkage and Swelling Properties of Coal on Geologic Sequestration of Carbon Dioxide

The potential for enhanced methane production and geologic sequestration of carbon dioxide in coalbeds needs to be evaluated before large-scale sequestration projects are undertaken. Geologic sequestration of carbon dioxide in deep unmineable coal seams with the potential for enhanced coalbed methane production has become a viable option to reduce greenhouse gas emissions. The coal matrix is believed to shrink during methane production and swell during the injection of carbon dioxide, causing changes in tlie cleat porosity and permeability of the coal seam. However, the influence of swelling and shrinkage, and the geomechanical response during the process of carbon dioxide injection and methane recovery, are not well understood. A three-dimensional swelling and shrinkage model based on constitutive equations that account for the coupled fluid pressure-deformation behavior of a porous medium was developed and implemented in an existing reservoir model. Several reservoir simulations were performed at a field site located in the San Juan basin to investigate the influence of swelling and shrinkage, as well as other geomechanical parameters, using a modified compositional coalbed methane reservoir simulator (modified PSU-COALCOMP). The paper presents numerical results for interpretation of reservoir performance during injection of carbon dioxide at this site. Available measured data at the …
Date: May 1, 2007
Creator: Siriwardane, H. J.; Gondle, R. & Smith, D. H.
Object Type: Article
System: The UNT Digital Library