Theoretical Progress for the Associated Production of a Higgs Boson With Heavy Quarks at Hadron Colliders. (open access)

Theoretical Progress for the Associated Production of a Higgs Boson With Heavy Quarks at Hadron Colliders.

The production of a Higgs boson in association with a pair of t{bar t} or b{bar b} quarks plays a very important role at both the Tevatron and the Large Hadron Collider. The theoretical prediction of the corresponding cross sections has been improved by including the complete next-to-leading order QCD corrections. After a brief introduction, we review the results obtained for both the Tevatron and the Large Hadron Collider.
Date: July 17, 2003
Creator: Dawson, S.; Jackson, C. B.; Orr, L. H.; Reina, L. & Wackeroth, D.
Object Type: Article
System: The UNT Digital Library
Moment Magnitude Calibration for the Eastern Mediterranean Region from Broadband Regional Coda Envelopes (open access)

Moment Magnitude Calibration for the Eastern Mediterranean Region from Broadband Regional Coda Envelopes

The following is an overview of results from ROA01-32 that focuses on an empirical method of calibrating stable seismic source moment-rate spectra derived from regional coda envelopes using broadband stations. The main goal was to develop a regional magnitude methodology that had the following properties: (1) it is tied to an absolute scale and is thus unbiased and transportable; (2) it can be tied seamlessly to the well-established teleseismic and regional catalogs; (3) it is applicable to small events using a sparse network of regional stations; (4) it is flexible enough to utilize S{sub n}-coda, L{sub g}-coda, or P-coda, whichever phase has the best signal-to-noise ratio. The results of this calibration yield source spectra and derived magnitudes that were more stable than any other direct-phase measure to date. Our empirical procedure accounted for all propagation, site, and S-to-coda transfer function effects. The resultant coda-derived moment-rate spectra were used to provide traditional band-limited magnitude (e.g., M{sub L}, m{sub b} etc.) as well as an unbiased, unsaturated magnitude (moment magnitude, M{sub w}) that is tied to a physical measure of earthquake size (i.e., seismic moment). We validated our results by comparing our coda-derived moment estimates with those obtained from long-period waveform modeling. …
Date: July 17, 2003
Creator: Mayeda, K; Eken, T; Hofstetter, A; Turkelli, N; O'Boyle, J; Orgulu, G et al.
Object Type: Article
System: The UNT Digital Library
Nonradiological Environmental Report Maamora Site, Morocco (open access)

Nonradiological Environmental Report Maamora Site, Morocco

Under the Sister Laboratory Arrangement between Lawrence Livermore National Laboratory (LLNL) and the Moroccan National Center for Nuclear Energy Sciences and Techniques (CNESTEN), environmental sampling and analysis were performed to assess the background concentrations of nonradiological constituents in various environmental media at the Maamora Forest CNESTEN Laboratory Site. Samples were collected from surface soil, surface water and groundwater wells, short-lived vegetation (mainly native grass), and long-lived vegetation (cork oak). Samples were collected inside the property fence line, in the buffer zone surrounding the site, and off site at water locations. The soil and vegetation samples were analyzed for metals and pesticides and screened for polychlorinated biphenyls (PCBs); the water samples were analyzed for metals, general minerals, and pesticides and screened for PCBs.
Date: July 17, 2003
Creator: Althouse, P E; Blake, R G; Bandong, B B; Belghit, H & Dehbi, N
Object Type: Report
System: The UNT Digital Library
Integrating diverse calibration products to improve seismic location (open access)

Integrating diverse calibration products to improve seismic location

The monitoring of nuclear explosions on a global basis requires accurate event locations. As an example, under the Comprehensive Test Ban Treaty, the size of an on-site inspection search area is 1,000 square kilometers or approximately 17 km accuracy assuming a circular area. This level of accuracy is a significant challenge for small events that are recorded using a sparse regional network. In such cases, the travel-time of seismic energy is strongly affected by crustal and upper mantle heterogeneity and large biases can result. This can lead to large systematic errors in location and, more importantly, to invalid error bounds associated with location estimates. Corrections can be developed and integrated to correct for these biases. These path corrections take the form of both three-dimensional model corrections along with three-dimensional empirically based travel time corrections. LLNL is currently working to integrate a diverse set of three-dimensional velocity model and empirical based travel-time products into one consistent and validated calibration set. To perform this task, we have developed a hybrid approach that uses three-dimensional model corrections for a region and then uses reference events when available to improve the path correction. This Bayesian kriging approach uses the best apriori three-dimensional velocity model …
Date: July 17, 2000
Creator: Schultz, C; Myers, S; Swenson, J; Flanagan, M; Pasyanos, M; Bhattacharyya, J et al.
Object Type: Article
System: The UNT Digital Library
Symmetry Experiments on Omega with LMJ like Multiple Beam Cones Irradation (open access)

Symmetry Experiments on Omega with LMJ like Multiple Beam Cones Irradation

We carried out a set of experiments on the Omega laser facility at Rochester with Laser MegaJoule (LMJ) like indirect drive irradiation. We studied the irradiation non-uniformity with the foam ball radiography technique and the implosion symmetry with (D{sub 2} + Argon) filled capsules core emission. Cylindrical ''Nova scale 1'' thin wall hohlraums were used. Forty of the Omega beams, arranged in three cones on each side of the hohlraum (5, 5, and lo), were used to create the X-ray drive. Eight additional beams were used on a Ti source to radiograph the foam balls. The shaped laser pulse was about 3 ns duration. The radiation drive was measured on each shot. The images were recorded with a 5 prn resolution Gated X-ray Imager coupled to a CCD camera.
Date: July 17, 2000
Creator: Richard, A L; Jadaud, J P; Dague, N; Monteil, M C; Turner, R E; Bradley, D et al.
Object Type: Article
System: The UNT Digital Library
Experiential Education in Groundwater Hydrology: Bridging the Technical-Policy-Populace Gap Final Report (open access)

Experiential Education in Groundwater Hydrology: Bridging the Technical-Policy-Populace Gap Final Report

It is well recognized that half the countries in the world will face significant fresh water shortages in the next 20 years, due largely to growing populations and increased agricultural and industrial demands (Gleick, 1997). These shortages will significantly limit economic growth, decrease the quality of life and human health for billions of people, and could potentially lead to violence and conflict over securing scarce supplies of water. In the Middle East, groundwater represents an important part of water supply in most locations, yet it is the least understood and one of the most fragile components of the entire water resource system. The occurrence of water underground contributes to the illusion of an infinite resource that is immune to anthropogenic activities. Nevertheless, as has been learned in the West, it can become highly impaired through the actions of man--through the disposal of human, animal, or industrial wastes, from excessive irrigation and fertilization practices in agriculture, or from simple overproduction and overexploitation--and can remain so for decades or even centuries. Finding solutions to groundwater resource and quality problems can be complex, time consuming, and costly. As is the case in many places in the world, but especially in the Middle East, …
Date: July 17, 2003
Creator: Tompson, A. F. B.; Maxwell, R. M.; Richardson, J. H.; El Sha'r, W. A.; Rihani, J. F. F.; El-Naser, H. et al.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Improvements in Off-Center Focusing in an X-ray Streak Camera (open access)

Improvements in Off-Center Focusing in an X-ray Streak Camera

Due to the planar construction of present x-ray streak tubes significant off-center defocusing is observed in both static and dynamic images taken with one-dimensional resolution slits. Based on the streak tube geometry curved photocathodes with radii of curvature ranging from 3.5 to 18 inches have been fabricated. We report initial off-center focusing performance data on the evaluation of these ''improved'' photocathodes in an X-ray streak camera and an update on the theoretical simulations to predict the optimum cathode curvature.
Date: July 17, 2003
Creator: McDonald, J. W.; Weber, F.; Holder, J. P. & Bell, P. M.
Object Type: Article
System: The UNT Digital Library
Chemoselective Attachment of Biologically Active Proteins to Surfaces by Expressed Protein Ligation and its Application for creating Protein Arrays (open access)

Chemoselective Attachment of Biologically Active Proteins to Surfaces by Expressed Protein Ligation and its Application for creating Protein Arrays

None
Date: July 17, 2004
Creator: Camarero, J A; Kwon, Y & Coleman, M A
Object Type: Article
System: The UNT Digital Library
Verification& Validation (V&V) Guidelines and Quantitative Reliability at Confidence (QRC): Basis for an Investment Strategy (open access)

Verification& Validation (V&V) Guidelines and Quantitative Reliability at Confidence (QRC): Basis for an Investment Strategy

This paper represents an attempt to summarize our thoughts regarding various methods and potential guidelines for Verification and Validation (V&V) and Uncertainty Quantification (UQ) that we have observed within the broader V&V community or generated ourselves. Our goals are to evaluate these various methods, to apply them to computational simulation analyses, and integrate them into methods for Quantitative Certification techniques for the nuclear stockpile. We describe the critical nature of high quality analyses with quantified V&V, and the essential role of V&V and UQ at specified Confidence levels in evaluating system certification status. Only after V&V has contributed to UQ at confidence can rational tradeoffs of various scenarios be made. UQ of performance and safety margins for various scenarios and issues are applied in assessments of Quantified Reliability at Confidence (QRC) and we summarize with a brief description of how these V&V generated QRC quantities fold into a Value-Engineering methodology for evaluating investment strategies. V&V contributes directly to the decision process for investment, through quantification of uncertainties at confidence for margin and reliability assessments. These contributions play an even greater role in a Comprehensive Test Ban Treaty (CTBT) environment than ever before, when reliance on simulation in the absence of …
Date: July 17, 2002
Creator: Logan, R W & Nitta, C K
Object Type: Report
System: The UNT Digital Library
Second Quarter Hanford Seismic Report for Fiscal Year 2000 (open access)

Second Quarter Hanford Seismic Report for Fiscal Year 2000

Hanford Seismic Monitoring provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network (HSN) for the U.S. Department of Energy and its contractors. Hanford Seismic Monitoring also locates and identifies sources of seismic activity and monitors changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, Natural Phenomena Hazards assessments, and engineering design and construction. In addition, the seismic monitoring organization works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The HSN and the Eastern Washington Regional Network (EWRN) consist of 42 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Monitoring staff. The HSN uses 21 sites and the EWRN uses 36 sites; both networks share 16 sites. The networks have 46 combined data channels because Gable Butte and Frenchman Hills East are three-component sites. The reconfiguration of the telemetry and recording systems was completed during the first quarter. All leased telephone lines have been eliminated and radio telemetry is now used exclusively. For the HSN, there were …
Date: July 17, 2000
Creator: Hartshorn, Donald C.; Reidel, Stephen P. & Rohay, Alan C.
Object Type: Report
System: The UNT Digital Library
Multilayers are enabling new science with x-ray free electron lasers (open access)

Multilayers are enabling new science with x-ray free electron lasers

Newly developed multilayer-based mirrors and optical elements enable the imaging of high-resolution structure and ultrafast dynamics of samples with the soft X-ray free electron laser, FLASH, at DESY in Hamburg. The FLASH free-electron laser (FEL) produces intense ultrashort soft X-ray pulses with more than 10{sup 8} times higher peak brightness as compared with the most advanced synchrotron radiation sources. This allows time-resolved X-ray imaging and holography of nanostructures with a temporal resolution approaching 10 fs, opening up new studies of laser-matter interactions and the dynamics of correlated systems. In addition, the ultrafast pulses can be used to obtain structural data before the onset of radiation damage. This vastly increases the dose that can be used to record images of biological samples and hence improving the resolution of images. The extreme power of the X-ray pulses poses a challenge, and new methods are required to harness them. The methods developed here will also pave the way to imaging at upcoming hard-X-ray FELs. With those sources, atomic-resolution imaging of single uncrystallized macromolecules may become possible. In the first demonstration of ultrafast X-ray imaging at FLASH, a micron-sized test object was illuminated by a single focused coherent FEL pulse (Fig. 1). The coherent …
Date: July 17, 2007
Creator: Bajt, S & Chapman, H N
Object Type: Article
System: The UNT Digital Library
Electron Backscatter Diffraction in Low Vacuum Conditions (open access)

Electron Backscatter Diffraction in Low Vacuum Conditions

Most current scanning electron microscopes (SEMs) have the ability to analyze samples in a low vacuum mode, whereby a partial pressure of water vapor is introduced into the SEM chamber, allowing the characterization of nonconductive samples without any special preparation. Although the presence of water vapor in the chamber degrades electron backscatter diffraction (EBSD) patterns, the potential of this setup for EBSD characterization of nonconductive samples is immense. In this chapter we discuss the requirements, advantages and limitations of low vacuum EBSD (LV-EBSD), and present how this technique can be applied to a two-phase ceramic composite as well as hydrated biominerals as specific examples of when LV-EBSD can be invaluable.
Date: July 17, 2008
Creator: El-Dasher, B S & Torres, S G
Object Type: Book
System: The UNT Digital Library
Monthly Health Information Report. June 1-30, 1950 (open access)

Monthly Health Information Report. June 1-30, 1950

None
Date: July 17, 2009
Creator: Boozer, A. H.
Object Type: Report
System: The UNT Digital Library
Studies of Bystander Effects in 3-D Tissue Systems Using a Low-LET Microbeam (open access)

Studies of Bystander Effects in 3-D Tissue Systems Using a Low-LET Microbeam

It is now accepted that biological effects may occur in cells that were not themselves traversed by ionizing radiation but are close to those that were. Little is known about the mechanism underlying such a bystander effect, although cell-to-cell communication is thought to be important. Previous work demonstrated a significant bystander effect for clonogenic survival and oncogenic transformation in C3H 10T(1/2) cells. Additional studies were undertaken to assess the importance of the degree of cell-to-cell contact at the time of irradiation on the magnitude of this bystander effect by varying the cell density. When 10% of cells were exposed to a range of 2-12 alpha particles, a significantly greater number of cells were inactivated when cells were irradiated at high density than at low density. In addition, the oncogenic transformation frequency was significantly higher in high-density cultures. These results suggest that when a cell is hit by radiation, the transmission of the bystander signal through cell-to-cell contact is an important mediator of the effect, implicating the involvement of intracellular communication through gap junctions. Additional studies to address the relationship between the bystander effect and the adaptive response were undertaken. A novel apparatus, where targeted and non-targeted cells were grown in …
Date: July 17, 2009
Creator: Brenner, David J.
Object Type: Report
System: The UNT Digital Library
EMSL Quarterly Highlights Report: FY09, 3rd Quarter (open access)

EMSL Quarterly Highlights Report: FY09, 3rd Quarter

This report outlines the science and publications that occurred at EMSL during the 3rd quarter of FY09.
Date: July 17, 2009
Creator: Showalter, Mary Ann; Kathmann, Loel E.; Manke, Kristin L. & Wiley, Julie G.
Object Type: Report
System: The UNT Digital Library
RAPID METHOD FOR DETERMINATION OF RADIOSTRONTIUM IN EMERGENCY MILK SAMPLES (open access)

RAPID METHOD FOR DETERMINATION OF RADIOSTRONTIUM IN EMERGENCY MILK SAMPLES

A new rapid separation method for radiostrontium in emergency milk samples was developed at the Savannah River Site (SRS) Environmental Bioassay Laboratory (Aiken, SC, USA) that will allow rapid separation and measurement of Sr-90 within 8 hours. The new method uses calcium phosphate precipitation, nitric acid dissolution of the precipitate to coagulate residual fat/proteins and a rapid strontium separation using Sr Resin (Eichrom Technologies, Darien, IL, USA) with vacuum-assisted flow rates. The method is much faster than previous method that use calcination or cation exchange pretreatment, has excellent chemical recovery, and effectively removes beta interferences. When a 100 ml sample aliquot is used, the method has a detection limit of 0.5 Bq/L, well below generic emergency action levels.
Date: July 17, 2008
Creator: Maxwell, S. & Culligan, B.
Object Type: Article
System: The UNT Digital Library
Steel-SiC Metal Matrix Composite Development (open access)

Steel-SiC Metal Matrix Composite Development

The goal of this project is to develop a method for fabricating SiC-reinforced high-strength steel. We are developing a metal-matrix composite (MMC) in which SiC fibers are be embedded within a metal matrix of steel, with adequate interfacial bonding to deliver the full benefit of the tensile strength of the SiC fibers in the composite.
Date: July 17, 2005
Creator: Smith, Don D.
Object Type: Report
System: The UNT Digital Library
Physical Energy Accounting in California: A Case Study of Cellulosic Ethanol Production (open access)

Physical Energy Accounting in California: A Case Study of Cellulosic Ethanol Production

California's target for greenhouse gas reduction in part relies on the development of viable low-carbon fuel alternatives to gasoline. It is often assumed that cellulosic ethanol--ethanol made from the structural parts of a plant and not from the food parts--will be one of these alternatives. This study examines the physical viability of a switchgrass-based cellulosic ethanol industry in California from the point of view of the physical requirements of land, water, energy and other material use. Starting from a scenario in which existing irrigated pastureland and fiber-crop land is converted to switchgrass production, the analysis determines the total acreage and water supply available and the resulting total biofuel feedstock output under different assumed yields. The number and location of cellulosic ethanol biorefineries that can be supported is also determined, assuming that the distance from field to biorefinery would be minimized. The biorefinery energy input requirement, available energy from the fraction of biomass not converted to ethanol, and energy output is calculated at various levels of ethanol yields, making different assumptions about process efficiencies. The analysis shows that there is insufficient biomass (after cellulose separation and fermentation into ethanol) to provide all the process energy needed to run the biorefinery; hence, …
Date: July 17, 2008
Creator: Coughlin, Katie & Fridley, David
Object Type: Report
System: The UNT Digital Library
Final technical Report DE-FG02-06ER65187 (open access)

Final technical Report DE-FG02-06ER65187

Simulations from the University of Wisconsin Non-Hydrostatic Modeling System (UW-NMS) along with those from other models indicate a strong tendency to overproduce ice, resulting in a decimation of the liquid portion of mixed-phase stratus through the Bergeron-Findeissen process. Immersion freezing was illustrated to be a major contributor to ice production within these cloud layers, and aerosol properties were illustrated to be an important consideration in the simulation of this process. In particular, the soluble mass fraction and aerosol insoluble mass type were demonstrated to influence simulation of the immersion freezing process, Data collected by the Arctic High Spectral Resolution Lidar and Millimeter Cloud Radar during the M-PACE period was analyzed in order to provide a statistical dataset for validation of simulations of mixed-phase stratus. 270 hours of single-layer cases were reviewed, and mean values for cloud base height, cloud thickness, cloud optical thickness, cloud temperature, wind direction, and liquid and ice particle size, particle number density, and water content were derived.
Date: July 17, 2009
Creator: Eloranta, Edwin
Object Type: Report
System: The UNT Digital Library
Report - Final Design - Ball Creek Realignment, Restoration and Reconnection with the Kootenai River Boundary County, Idaho. (open access)

Report - Final Design - Ball Creek Realignment, Restoration and Reconnection with the Kootenai River Boundary County, Idaho.

None
Date: July 17, 2009
Creator: Fealko, Jeffrey J.; Scott, Jason R. & Homza, Matthew K.
Object Type: Report
System: The UNT Digital Library
Complex band structure under plane-wave nonlocal pseudopotential Hamiltonian of metallic wires and electrodes (open access)

Complex band structure under plane-wave nonlocal pseudopotential Hamiltonian of metallic wires and electrodes

We present a practical approach to calculate the complex band structure of an electrode for quantum transport calculations. This method is designed for plane wave based Hamiltonian with nonlocal pseudopotentials and the auxiliary periodic boundary condition transport calculation approach. Currently there is no direct method to calculate all the evanescent states for a given energy for systems with nonlocal pseudopotentials. On the other hand, in the auxiliary periodic boundary condition transport calculation, there is no need for all the evanescent states at a given energy. The current method fills this niche. The method has been used to study copper and gold nanowires and bulk electrodes.
Date: July 17, 2009
Creator: Yang, Chao
Object Type: Report
System: The UNT Digital Library
Rapid Cycling Medical Synchrotron (open access)

Rapid Cycling Medical Synchrotron

The goal of this CRADA was to perform early prototyping on the Rapid Cycling Medical Synchrotron, leading to more accurate cost and schedule estimates.
Date: July 17, 2007
Creator: Peggs, Stephen
Object Type: Report
System: The UNT Digital Library
Quantum Mechanical Corrections to Simulated Shock Hugoniot Temperatures (open access)

Quantum Mechanical Corrections to Simulated Shock Hugoniot Temperatures

The authors present a straightforward method for the inclusion of quantum nuclear vibrational effects in molecular dynamics calculations of shock Hugoniot temperatures. Using a grueneisen equation of state and a quasi-harmonic approximation to the vibrational energies, they derive a simple, post-processing method for calculation of the quantum corrected Hugoniot temperatures. They have used our novel technique on ab initio simulations of both shock compressed water and methane. Our results indicate significantly closer agreement with all available experimental temperature data for these two systems. Our formalism and technique can be easily applied to a number of different shock compressed molecular liquids or covalent solids, and has the potential to decrease the large uncertainties inherent in many experimental Hugoniot temperature measurements of these systems.
Date: July 17, 2009
Creator: Goldman, N; Reed, E & Fried, L E
Object Type: Article
System: The UNT Digital Library
Annual Report to the Bonneville Power Administration, Reporting Period: April 2008 - February 2009 [re: "Survival and Growth in the Columbia River Plume and north California Current"]. (open access)

Annual Report to the Bonneville Power Administration, Reporting Period: April 2008 - February 2009 [re: "Survival and Growth in the Columbia River Plume and north California Current"].

We have made substantial progress toward our objectives outlined in our BPA supported proposal entitled 'Columbia River Basin Juvenile Salmonids: Survival and Growth in the Columbia River Plume and northern California Current' which we report on herein. During 2008, we were able to successfully conduct 3 mesoscale cruises. We also were able to conduct 7 biweekly predator cruises, along with substantial shore-based visual observations of seabirds. Detailed results of the mesoscale cruises are available in the Cruise Reports and summarized in the next section. We have taken a proactive approach to getting the results of our research to fisheries managers and the general public. We have begun to make annual predictions based on ocean conditions of the relative survival of juvenile coho and Chinook salmon well before they return as adults. This is based on both biological and physical indicators that we measure during our surveys or collect from outside data sources. Examples of our predictions for 2009 and 2010 are available on the following web site: http://www.nwfsc.noaa.gov/research/divisions/fed/oeip/a-ecinhome.cfm.
Date: July 17, 2009
Creator: Northwest Fisheries Science Center, NOAA Fisheries; Cooperative Institute for Marine Resources Studies, Oregon State University & OGI School of Science & Engineering, Oregon Health Sciences University.
Object Type: Report
System: The UNT Digital Library