STRANGENESS PRODUCTION AS A FUNCTION OF SYSTEM SIZE AND ENERGY OF RHIC. (open access)

STRANGENESS PRODUCTION AS A FUNCTION OF SYSTEM SIZE AND ENERGY OF RHIC.

In this paper we report on strangeness measurements in p+p, Au+Au and Cu+Cu collisions at different energies in the STAR detector at RHIC. We will focus on two momentum regions in particular: Firstly we look at strangeness enhancement in A+A collisions with respect to p+p. These yields are dominated by low transverse momentum. We compare the enhancements from Au+Au and Cu+Cu data at {radical}s{sub NN} = 200 GeV with Pb+Pb data at {radical}s{sub NN} = 17.2 GeV and find that the enhancement does not scale with N{sub part} as expected, but rather scales with N{sub part}{sup 1/3}, where N{sub part} represents the number of participants; We then examine {Lambda}/K{sub S}{sup 0} ratios at intermediate transverse momentum in both Au+Au and Cu+Cu data where we find a greater enhancement in Cu+Cu compared to Au+Au data when we compare integrated ratios between 1.5 < p{sub T} < 3.5 GeV/c.
Date: July 19, 2007
Creator: LAMONT,M.
Object Type: Article
System: The UNT Digital Library
New cubic phase of lithium nitride to 200 GPa (open access)

New cubic phase of lithium nitride to 200 GPa

We present a new cubic ({gamma}) Li{sub 3}N phase discovered above 40({+-}5) GPa. Structure and electronic bands are examined at high pressure with synchrotron x-ray diffraction and inelastic x-ray scattering in a diamond anvil cell, and also with first-principles calculations. We observe a dramatic band-gap widening and volume collapse at the phase transition. {gamma}-Li{sub 3}N remains extremely stable and ionic to 200 GPa, with predicted metallization near 8 TPa. The high structural stability, wide band-gap and simple electronic structure of {gamma}-Li{sub 3}N are analogous to that of such lower valence closed-shell solids as NaCl, MgO and Ne, meriting its use as a low-Z internal pressure standard.
Date: July 19, 2005
Creator: Lazicki, A.; Maddox, B.; Evans, W.; Yoo, C. S.; McMahan, A. K.; Pickett, W. E. et al.
Object Type: Article
System: The UNT Digital Library
Epigenetic reversion of breast carcinoma phenotype is accompanied by DNA sequestration (open access)

Epigenetic reversion of breast carcinoma phenotype is accompanied by DNA sequestration

The importance of microenvironment and context in regulation of tissue-specific genes is finally well established. DNA exposure to, or sequestration from, nucleases can be used to detect differences in higher order chromatin structure in intact cells without disturbing cellular or tissue architecture. To investigate the relationship between chromatin organization and tumor phenotype, we utilized an established 3-D assay where normal and malignant human breast cells can be easily distinguished by the morphology of the structures they make (acinus-like vs tumor-like, respectively). We show that these phenotypes can be distinguished also by sensitivity to AluI digestion where the malignant cells are resistant to digestion relative to non-malignant cells. Reversion of the T4-2 breast cancer cells by either cAMP analogs, or a phospatidylinositol 3-kinase (P13K) inhibitor not only reverted the phenotype, but also the chromatin sensitivity to AluI. By using different cAMP-analogs, we show that the cAMP-induced phenotypic reversion, polarization, and shift in DNA organization act through a cAMP-dependent-protein-kinase A-coupled signaling pathway. Importantly, inhibitory antibody to fibronectin also reverted the malignant phenotype, polarized the acini, and changed chromatin sequestration. These experiments show not only that modifying the tumor microenvironment can alter the organization of tumor cells but also that architecture of the …
Date: July 19, 2006
Creator: Sandal, Tone; Valyi-Nagy, Klara; Spencer, Virginia A.; Folberg,Robert; Bissell, Mina J. & Maniotis, Andrew J.
Object Type: Article
System: The UNT Digital Library
Optical Fiber Sensor Instrumentation for Slagging Coal Gasifiers (open access)

Optical Fiber Sensor Instrumentation for Slagging Coal Gasifiers

Coal gasifier is one of the most promising solutions for clean fossil energy. Refractory thickness monitoring and online real-time temperature measurement is needed for improved reliability and advanced process control for current and future generation power plants. The objective of this program is to design and implement an optical fiber based sensing system that could potentially be used to monitor refractory wall thickness and temperature inside a coal gasifier. For the thickness monitoring, the system should be able to operate at temperatures up to 1000 C. For this temperature range, silica fiber can still work so it is chosen for the sensor design. The measurement is based on a photon counting optical time domain reflectometer. A narrow light pulse is launched into a silica fiber which could be embedded into the gasifier refractory wall, and is partially reflected by the far end of the fiber. The time of flight of the light pulse in the fiber then gives an indication of the position of the fiber end, which is a function of the wall thickness when the fiber is embedded. Results obtained show a measurement accuracy of {+-}2cm in environment of 1000 C with a saw cut fiber end. When …
Date: July 19, 2008
Creator: Wang, Anbo & Cooper, Kristie
Object Type: Report
System: The UNT Digital Library
General Corrosion and Passive Film Stability (open access)

General Corrosion and Passive Film Stability

This report summarizes both general corrosion of Alloy 22 from 60 to 220 C and the stability of the passive (oxide) film from 60 to 90 C over a range of solution compositions that are relevant to the in-drift chemical environment at the waste package surface. The general corrosion rates were determined by weight-loss measurements in a range of complex solution compositions representing the products of both the evaporation of seepage water and also the deliquescence of dust previously deposited on the waste canisters. These data represent the first weight-loss measurements performed by the program at temperatures above 90 C. The low corrosion rates of Alloy 22 are attributed to the protective oxide film that forms at the metal surface. In this report, changes in the oxide film composition are correlated with weight loss at the higher temperatures (140-220 C) where film characterization had not been previously performed. The stability of the oxide film was further analyzed by conducting a series of electrochemical tests in progressively more acidic solutions to measure the general corrosion rates in solutions that mimic crevice or pit environments.
Date: July 19, 2005
Creator: Orme, C; Gray, J; Hayes, J; Wong, L; Rebak, R; Carroll, S et al.
Object Type: Report
System: The UNT Digital Library
History and Evolution of Control Banding: A Review (open access)

History and Evolution of Control Banding: A Review

Control Banding (CB) strategies offer simplified solutions for controlling worker exposures to constituents often encountered in the workplace. The original CB model was developed within the pharmaceutical industry; however, the modern movement involves models developed for non-experts to input hazard and exposure potential information for bulk chemical processes, receiving control advice as a result. The CB approach utilizes these models for the dissemination of qualitative and semi-quantitative risk assessment tools being developed to complement the traditional industrial hygiene model of air sampling and analysis. It is being applied and tested in small and medium size enterprises (SMEs) within developed countries and industrially developing countries; however, large enterprises (LEs) have also incorporated these strategies within chemical safety programs. Existing research of the components of the most available CB model, the Control of Substances Hazardous to Health (COSHH) Essentials, has shown that exposure bands do not always provide adequate margins of safety, that there is a high rate of under-control errors, that it works better with dusts than with vapors, that there is an inherent inaccuracy in estimating variability, and that when taken together the outcomes of this model may lead to potentially inappropriate workplace confidence in chemical exposure reduction in some …
Date: July 19, 2006
Creator: Zalk, D. & Nelson, D.
Object Type: Article
System: The UNT Digital Library
Performance and scaling of locally-structured grid methods forpartial differential equations (open access)

Performance and scaling of locally-structured grid methods forpartial differential equations

In this paper, we discuss some of the issues in obtaining high performance for block-structured adaptive mesh refinement software for partial differential equations. We show examples in which AMR scales to thousands of processors. We also discuss a number of metrics for performance and scalability that can provide a basis for understanding the advantages and disadvantages of this approach.
Date: July 19, 2007
Creator: Colella, Phillip; Bell, John; Keen, Noel; Ligocki, Terry; Lijewski, Michael & Van Straalen, Brian
Object Type: Article
System: The UNT Digital Library
On-Line Coolant Chemistry Analysis (open access)

On-Line Coolant Chemistry Analysis

Impurities in the gas coolant of the space nuclear power plant (SNPP) can provide valuable indications of problems in the reactor and an overall view of system health. By monitoring the types and amounts of these impurities, much can be implied regarding the status of the reactor plant. However, a preliminary understanding of the expected impurities is important before evaluating prospective detection and monitoring systems. Currently, a spectroscopy system is judged to hold the greatest promise for monitoring the impurities of interest in the coolant because it minimizes the number of entry and exit points to the plant and provides the ability to detect impurities down to the 1 ppm level.
Date: July 19, 2006
Creator: Bachman, LM
Object Type: Report
System: The UNT Digital Library
Long Period Variables in the LMC: Results from MACHO and 2Mass (open access)

Long Period Variables in the LMC: Results from MACHO and 2Mass

We use the eight year light curve database from the MACHO (MAssive Compact Halo Objects) project together with infrared colors and magnitudes from 2MASS (the Two Micron All Sky Survey) to identify a sample of 22,000 long period variables in the Large Magellanic Cloud (referred to hereafter as LMC LPVs). A period luminosity diagram of these stars reveals six well defined sequences, in substantial agreement with previous analyses of samples from OGLE (Optical Gravitational Lensing Experiment). In our analysis we identify analogues to galactic LPVs in the LMC LPV sample. We find that carbon dominated AGB stars populate only two of the sequences, one of which includes the Mira variables. The high luminosity end of the same two sequences are also the location of the only stars with J K{sub s} > 2, indicating that they are enshrouded in dust. The unknown mechanism that produces the variability of the last sequence--those stars with long secondary periods--produces different morphology in the period luminosity diagram than what is seen in the first four sequences, which are thought to be caused by pulsation. In particular, the last sequence extends to lower luminosity RGB stars and the luminosity function does not peak among the …
Date: July 19, 2004
Creator: Fraser, O J; Cook, K H; Keller, S C & Hawley, S L
Object Type: Article
System: The UNT Digital Library
300-Area VOC Program Slug Test Characterization Results for Selected Test/Depth Intervals Conducted During the Drilling of Well 399-3-21 (open access)

300-Area VOC Program Slug Test Characterization Results for Selected Test/Depth Intervals Conducted During the Drilling of Well 399-3-21

This report presents brief test descriptions and analysis results for multiple, stress-level slug tests that were performed at selected test/depth intervals within well 399-3-21 as part of the 300-Area volatile organic compound characterization program. The test intervals were characterized as the borehole was advanced to its final drill depth (45.7 m) and before its completion as a monitor-well facility. The primary objective of the slug tests was to provide information pertaining to the vertical distribution of hydraulic conductivity with depth at this location and to select the final screen-depth interval for the monitor well. This type of characterization information is important for predicting/simulating contaminant migration (i.e., numerical flow/transport modeling) and designing proper monitor-well strategies within this area.
Date: July 19, 2007
Creator: Spane, Frank A.
Object Type: Report
System: The UNT Digital Library
Simple Common Plane contact detection algorithm for FE/FD methods (open access)

Simple Common Plane contact detection algorithm for FE/FD methods

Common-plane (CP) algorithm is widely used in Discrete Element Method (DEM) to model contact forces between interacting particles or blocks. A new simple contact detection algorithm is proposed to model contacts in FE/FD methods which is similar to the CP algorithm. The CP is defined as a plane separating interacting faces of FE/FD mesh instead of blocks or particles in the original CP method. The method does not require iterations. It is very robust and easy to implement both in 2D and 3D case.
Date: July 19, 2006
Creator: Vorobiev, O
Object Type: Article
System: The UNT Digital Library
Study of the Electron Beam Dynamics in the Fermi @ Elettra Linac (open access)

Study of the Electron Beam Dynamics in the Fermi @ Elettra Linac

A study of the electron beam dynamics in the linac is conducted for the FERMI free electron laser (FEL) founded for construction at the Sincrotrone Trieste.
Date: July 19, 2006
Creator: Cornacchia, M.; Craievich, P.; Di Mitri, S.; Pogorelov, I.; Qiang, J.; Venturini, M. et al.
Object Type: Article
System: The UNT Digital Library
Characterization of the PEP-II Colliding-Beam Phase Space by the Boost Method (open access)

Characterization of the PEP-II Colliding-Beam Phase Space by the Boost Method

We present a novel approach to characterize the colliding-beam phase space at the interaction point of the energy-asymmetric PEP-II B-Factory. The method exploits the fact that the transverse-boost distribution of e{sup +}e{sup -} {yields} {mu}{sup +}{mu}{sup -} events reconstructed in the BABAR detector reflects that of the colliding electrons and positrons. The mean boost direction, when combined with the measured orientation of the luminous ellipsoid, determines the e{sup +}-e{sup -} crossing angles. The average angular spread of the transverse boost vector provides an accurate measure of the angular divergence of the incoming high-energy beam, confirming the presence of a sizeable dynamic-{beta} effect. The longitudinal and transverse dependence of the boost angular spread also allow to extract from the continuously-monitored distributions detailed information about the emittances and IP {beta}-functions of both beams during high-luminosity operation.
Date: July 19, 2006
Creator: Weaver, M.; Kozanecki, W. & Viaud, B.
Object Type: Article
System: The UNT Digital Library
NUCLEAR NON-PROLIFERATION-TASK 1: Deployable Plume and Aerosol Release Prediction and Tracking System (open access)

NUCLEAR NON-PROLIFERATION-TASK 1: Deployable Plume and Aerosol Release Prediction and Tracking System

This contract was awarded in response to a proposal in which a deployable plume and aerosol release prediction and tracking system would be designed, fabricated, and tested. The system would gather real time atmospheric data and input it into a real time atmospheric model that could be used for plume predition and tracking. The system would be able to be quickly deployed by aircraft to points of interest or positioned for deployment by vehicles. The system would provide three dimensional (u, v, and w) wind vector data, inversion height measurements, surface wind information, classical weather station data, and solar radiation. The on-board real time computer model would provide the prediction of the behavior of plumes and released aerosols.
Date: July 19, 2006
Creator: John Kleppe, Ph.D., William Norris, Ph.D., Mehdi Etezada, Ph.D., P.E.
Object Type: Report
System: The UNT Digital Library
Demonstrating a Market-Based Approach to the Reclamation of Mined Lands in West Virginia (open access)

Demonstrating a Market-Based Approach to the Reclamation of Mined Lands in West Virginia

This is the third quarter progress report of Phase II of a three-phase project to develop and evaluate the efficacy of developing multiple environmental market trading credits on a partially reclaimed surface mined site near Valley Point, Preston County, WV. Construction of the passive acid mine drainage (AMD) treatment system was completed but several modifications from the original design had to be made following the land survey and during construction to compensate for unforeseen circumstances. We continued to collect baseline quality data from the Conner Run AMD seeps to confirm the conceptual and final design for the passive AMD treatment system.
Date: July 19, 2006
Creator: Goodrich-Mahoney, John W. & Ziemkiewicz, Paul
Object Type: Report
System: The UNT Digital Library
Demonstrating a Market-Based Approach to the Reclamation of Mined Lands in West Virginia (open access)

Demonstrating a Market-Based Approach to the Reclamation of Mined Lands in West Virginia

None
Date: July 19, 2006
Creator: Goodrich-Mahoney, John W. & Ziemkiewicz, Paul
Object Type: Report
System: The UNT Digital Library
Demonstrating a Market-Based Approach to the Reclamation of Mined Lands in West Virginia (open access)

Demonstrating a Market-Based Approach to the Reclamation of Mined Lands in West Virginia

None
Date: July 19, 2006
Creator: Goodrich-Mahoney, John W. & Ziemkiewicz, Paul
Object Type: Report
System: The UNT Digital Library
Demonstrating a Market-Based Approach to the Reclamation of Mined Lands in West Virginia (open access)

Demonstrating a Market-Based Approach to the Reclamation of Mined Lands in West Virginia

None
Date: July 19, 2006
Creator: Goodrich-Mahoney, John W. & Ziemkiewicz, Paul
Object Type: Report
System: The UNT Digital Library
An Experimental Investigation of Detonation Corner-Turning Using High Resolution Radiography (open access)

An Experimental Investigation of Detonation Corner-Turning Using High Resolution Radiography

We have performed experiments investigating detonation corner turning over a range of high-explosives including LX-17, Composition B, LX-04 and Tritonal. The primary diagnostic utilized here was a new high-resolution x-ray system that was capable of recording a time sequence of the detonation process as it negotiated the corner of interest and propagated. For LX-17 our data detail the formation of a significant dead-zone. Although the detonation eventually turned the corner in LX-17, the dead zone persisted to late times and evidence exists that it never was consumed by either detonation or fast combustion processes. In LX-17 the detonations ability to corner-turn increases as the density is reduced. Furthermore, lowering the density decreases the size of the dead-zone and alters its shape. The other high-explosives investigated were able to turn the corner immediately with no indication of any dead-zone formation.
Date: July 19, 2006
Creator: Molitoris, J D; Andreski, H G; Garza, R G; Batteux, J D & Souers, P C
Object Type: Article
System: The UNT Digital Library
Gas production potential of disperse low-saturation hydrateaccumulations in oceanic sediments (open access)

Gas production potential of disperse low-saturation hydrateaccumulations in oceanic sediments

In this paper we evaluate the gas production potential ofdisperse, low-saturation (SH<0.1) hydrate accumulations in oceanicsediments. Such hydrate-bearing sediments constitute a significantportion of the global hydrate inventory. Using numerical simulation, weestimate (a) the rates of gas production and gas release from hydratedissociation, (b) the corresponding cumulative volumes of released andproduced gas, as well as (c) the water production rate and the mass ofproduced water from disperse, low-SH hydrate-bearing sediments subject todepressurization-induced dissociation over a 10-year production period.We investigate the sensitivity of items (a) to (c) to the followinghydraulic properties, reservoir conditions, and operational parameters:intrinsic permeability, porosity, pressure, temperature, hydratesaturation, and constant pressure at which the production well is kept.The results of this study indicate that, despite wide variations in theaforementioned parameters (covering the entire spectrum of suchdeposits), gas production is very limited, never exceeding a few thousandcubic meters of gas during the 10-year production period. Such lowproduction volumes are orders of magnitude below commonly acceptedstandards of economic viability, and are further burdened with veryunfavorable gas-to-water ratios. The unequivocal conclusion from thisstudy is that disperse, low-SH hydrate accumulations in oceanic sedimentsare not promising targets for gas production by means ofdepressurization-induced dissociation, and resources for early hydrateexploitation should be focused elsewhere.
Date: July 19, 2006
Creator: Moridis, George J. & Sloan, E. Dendy
Object Type: Article
System: The UNT Digital Library
2005 Annual Operations Report for INTEC Operable Unit 3-13, Group 1, Tank Farm Interim Action (open access)

2005 Annual Operations Report for INTEC Operable Unit 3-13, Group 1, Tank Farm Interim Action

This annual operations report describes the requirements followed and activities conducted to inspect, monitor, and maintain the items installed during performance of the Waste Area Group 3, Operable Unit 3-13, Group 1, Tank Farm Interim Action, at the Idaho Nuclear Technology and Engineering Center. This report describes inspection and monitoring activities fro the surface-sealed areas within the tank farm, concrete-lined ditches and culverts in and around the tank farm, the lift station, and the lined evaporation pond. These activities are intended to assure that the interim action is functioning adequately to meet the objectives stated in the Operable Unit 3-13, Record of Decision for the Group 1, Tank Farm Interim Action, (DOE/ID-10660) and as amended by the agreement to resolve dispute, which was effective in February 2003.
Date: July 19, 2006
Creator: Shanklin, D.
Object Type: Report
System: The UNT Digital Library
Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2006 (open access)

Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2006

Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a)(1)-(4) and Article 511.1 of the PNNL Radiological Control Program Description, personnel dosimetry shall be provided to 1) radiological workers who are likely to receive at least 100 mrem annually, and 2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2005 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program.
Date: July 19, 2007
Creator: Bivins, Steven R. & Stoetzel, Gregory A.
Object Type: Report
System: The UNT Digital Library
Analysis of Artificial Radiocarbon in Different Skeletal and Dental Tissue Types to Evaluate Date of Death (open access)

Analysis of Artificial Radiocarbon in Different Skeletal and Dental Tissue Types to Evaluate Date of Death

Radiocarbon dating, with special reference to the modern bomb-curve, can provide useful information to elucidate the date of death of skeletonized human remains. Interpretation can be enhanced with analysis of different types of tissues within a single skeleton because of the known variability of formation times and remodeling rates. Analysis of radiocarbon content of teeth, especially the enamel in tooth crowns provides information about the date of formation in the childhood years and in consideration of the known timing of tooth formation can be used to estimate the birth date after 1950 A.D. Radiocarbon analysis of modern cortical and trabecular bone samples from the same skeleton may allow proper placement on the pre-1963 or post-1963 sides of the bomb-curve since most trabecular bone generally undergoes more rapid remodeling than does most cortical bone. Pre-1963 bone formation would produce higher radiocarbon values for most trabecular bone than for most cortical bone. This relationship is reversed for formation after 1963. Radiocarbon analysis was conducted in this study on dental, cortical and trabecular bone samples from two adult individuals of known birth (1925 and 1926) and death dates (1995 and 1959). As expected, the dental results correspond to pre-bomb bomb-curve values reflecting conditions …
Date: July 19, 2005
Creator: Ubelaker, D. H.; Buchholz, B. A. & Stewart, J.
Object Type: Article
System: The UNT Digital Library
Fermi Timing and Synchronization System (open access)

Fermi Timing and Synchronization System

The Fermi FEL will depend critically on precise timing of its RF, laser and diagnostic subsystems. The timing subsystem to coordinate these functions will need to reliably maintain sub-100fs synchronicity between distant points up to 300m apart in the Fermi facility. The technology to do this is not commercially available, and has not been experimentally demonstrated in a working facility. Therefore, new technology must be developed to meet these needs. Two approaches have been researched by different groups working with the Fermi staff. At MIT, a pulse transmission scheme has been developed for synchronization of RF and laser devices. And at LBL, a CW transmission scheme has been developed for RF and laser synchronization. These respective schemes have advantages and disadvantages that will become better understood in coming years. This document presents the work done by both teams, and suggests a possible system design which integrates them both. The integrated system design provides an example of how choices can be made between the different approaches without significantly changing the basic infrastructure of the system. Overall system issues common to any synchronization scheme are also discussed.
Date: July 19, 2006
Creator: Wilcox, R.; Staples, J.; Doolittle, L.; Byrd, J.; Ratti, A.; Kaertner, F. X. et al.
Object Type: Report
System: The UNT Digital Library