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2013 METALS IN BIOLOGY GORDON RESEARCH CONFERENCE, JANUARY 20-25, 2013 (open access)

2013 METALS IN BIOLOGY GORDON RESEARCH CONFERENCE, JANUARY 20-25, 2013

Typical topics for lectures and posters include: biochemical and biophysical characterization of new metal containing proteins, enzymes, nucleic acids, factors, and chelators from all forms of life; synthesis, detailed characterization, and reaction chemistry of biomimetic compounds; novel crystal and solution structures of biological molecules and synthetic metal-chelates; discussions of the roles that metals play in medicine, maintenance of the environment, and biogeochemical processes; metal homeostasis; application of theory and computations to the structure and mechanism of metal-containing biological systems; and novel applications of spectroscopy to metals in biological systems.
Date: January 25, 2013
Creator: Rosenzweig, Amy
System: The UNT Digital Library
An analysis of the Cured-in-Place Pipe (CIPP) subproject of the sanitary sewer rehabilitation project (open access)

An analysis of the Cured-in-Place Pipe (CIPP) subproject of the sanitary sewer rehabilitation project

The comprehensive rehabilitation of the Lawrence Livermore National Laboratory Sanitary Sewer System centers around a Cured-in-Place Pipe project. Driven by regulatory requirements to eliminate the potential for exfiltration, a careful condition assessment of the existing infrastructure was conducted. Under programmatic constraints to maintain continuous operations, the INLINER USA cured-in-place pipe system was selected as the appropriate technology, and the project is currently under contract.
Date: January 25, 1994
Creator: Morrow, W. & Siemiatkoski, S.
System: The UNT Digital Library
Application Of Chiral Two- And Three-Nucleon Interactions To The 4He Photo-Disintegration (open access)

Application Of Chiral Two- And Three-Nucleon Interactions To The 4He Photo-Disintegration

We report on an ab initio calculation of the {sup 4}He total photo-absorption cross section using two- and three-nucleon interactions based upon chiral effective field theory. The microscopic treatment of the continuum problem is achieved using the Lorentz integral transform method, applied within the no-core shell model approach.
Date: January 25, 2008
Creator: Quaglioni, S & Navratil, P
System: The UNT Digital Library
AN APPROACH TO CHARACTERIZING & EVALUATING ALTERNATIVES FOR THE DECOMMISSIONING OF SUB-GRADE STRUCTURES AT THE PLUTONIUM FINISHING PLANT (PFP) (open access)

AN APPROACH TO CHARACTERIZING & EVALUATING ALTERNATIVES FOR THE DECOMMISSIONING OF SUB-GRADE STRUCTURES AT THE PLUTONIUM FINISHING PLANT (PFP)

In 2002, the Richland Operations Office (RL) of the US Department of Energy (DOE), the US Environmental Protection Agency (EPA), and the Washington State Department of Ecology (Ecology) developed milestones for transitioning the Plutonium Finishing Plant (PFP) facility to a clean slab-on-grade configuration. These milestones required developing an engineering evaluation/cost analysis (EF/CA) for the facility's sub-grade structures and installations as part of a series of evaluations intended to provide for the transition of the facility to a clean slab-on-grade configuration. In addition to supporting decisions for interim actions, the analyses of sub-grade structures and installations performed through this EE/CA will contribute to the remedial investigation feasibility study(ies) and subsequently to the final records of decision for the relevant operable units responsible for site closure in the 200 West Area of the Hanford Site.
Date: January 25, 2007
Creator: HOPKINS, A.M. & KLOS, D.B.
System: The UNT Digital Library
ASSESSING CHEMICAL HAZARDS AT THE PLUTONIUM FINISHING PLANT (PFP) FOR PLANNING FUTURE D&D (open access)

ASSESSING CHEMICAL HAZARDS AT THE PLUTONIUM FINISHING PLANT (PFP) FOR PLANNING FUTURE D&D

This paper documents the fiscal year (FY) 2006 assessment to evaluate potential chemical and radiological hazards associated with vessels and piping in the former plutonium process areas at Hanford's Plutonium Finishing Plant (PFP). Evaluations by PFP engineers as design authorities for specific systems and other subject-matter experts were conducted to identify the chemical hazards associated with transitioning the process areas for the long-term layup of PFP before its eventual final decontamination and decommissioning (D and D). D and D activities in the main process facilities were suspended in September 2005 for a period of between 5 and 10 years. A previous assessment conducted in FY 2003 found that certain activities to mitigate chemical hazards could be deferred safely until the D and D of PFP, which had been scheduled to result in a slab-on-grade condition by 2009. As a result of necessary planning changes, however, D and D activities at PFP will be delayed until after the 2009 time frame. Given the extended project and plant life, it was determined that a review of the plant chemical hazards should be conducted. This review to determine the extended life impact of chemicals is called the ''Plutonium Finishing Plant Chemical Hazards Assessment, …
Date: January 25, 2007
Creator: Hopkins, A. M.; Klos, D. B. & Minett, M. J.
System: The UNT Digital Library
Assessing out-of-band flare effects at the wafer level for EUV lithography (open access)

Assessing out-of-band flare effects at the wafer level for EUV lithography

To accurately estimate the flare contribution from the out-of-band (OOB), the integration of a DUV source into the SEMATECH Berkeley 0.3-NA Micro-field Exposure tool is proposed, enabling precisely controlled exposures along with the EUV patterning of resists in vacuum. First measurements evaluating the impact of bandwidth selected exposures with a table-top set-up and subsequent EUV patterning show significant impact on line-edge roughness and process performance. We outline a simulation-based method for computing the effective flare from resist sensitive wavelengths as a function of mask pattern types and sizes. This simulation method is benchmarked against measured OOB flare measurements and the results obtained are in agreement.
Date: January 25, 2010
Creator: George, Simi; Naulleau, Patrick; Kemp, Charles; Denham, Paul & Rekawa, Senajith
System: The UNT Digital Library
Asymptotic Freedom in the Diffusive Regime of Neutron Transport (open access)

Asymptotic Freedom in the Diffusive Regime of Neutron Transport

The accuracy of a numerical method for solving the neutron transport equation is limited by the smallest mean free path in the problem. Since problems in the asymptotic diffusive regimes have vanishingly small mean free paths, it seems hopeless, given a limited amount of computer memory, that an accurate solution can be obtained for these problems. However we found that the accuracy of a numerical method improves as the scattering ratio increases with the total cross section and the grid spacing held fixed for problems that are in the asymptotic diffusive regime. This phenomenon is independent of the numerical method and can be explained on physical grounds. The numerical results by the Diamond Difference Method are given to show this phenomenon.
Date: January 25, 2005
Creator: Chang, B.
System: The UNT Digital Library
Atomic processes in matter-antimatter interactions (open access)

Atomic processes in matter-antimatter interactions

Atomic processes dominate antiproton stopping in matter at nearly all energies of interest. They significantly influence or determine the antiproton annihilation rate at all energies around or below several MeV. This article reviews what is known about these atomic processes. For stopping above about 10 eV the processes are antiproton-electron collisions, effective at medium keV through high MeV energies, and elastic collisions with atoms and adiabatic ionization of atoms, effective from medium eV through low keB energies. For annihilation above about 10 eV is the enhancement of the antiproton annihilation rate due to the antiproton-nucleus coulomb attraction, effective around and below a few tens of MeV. At about 10 eV and below, the atomic rearrangement/annihilation process determines both the stopping and annihilation rates. Although a fair amount of theoretical and some experimental work relevant to these processes exist, there are a number of energy ranges and material types for which experimental data does not exist and for which the theoretical information is not as well grounded or as accurate as desired. Additional experimental and theoretical work is required for accurate prediction of antiproton stopping and annihilation for energies and material relevant to antiproton experimentation and application.
Date: January 25, 1988
Creator: Morgan, D. L.
System: The UNT Digital Library
Atomistic Simulation of Vacancy and Self-Interstitial Diffusion in Fe-Cu Alloys (open access)

Atomistic Simulation of Vacancy and Self-Interstitial Diffusion in Fe-Cu Alloys

Neutron hardening and embrittlement of pressure vessel steels is due to a high density of nanometer scale features, including Cu-rich precipitates which form as a result of radiation enhanced diffusion. High-energy displacement cascades generate large numbers of both isolated point defects and clusters of vacancies and interstitials. The subsequent clustering, diffusion and ultimate annihilation of primary damage is inherently coupled with solute transport and hence, the overall chemical and microstructural evolutions under irradiation. In this work, we present atomistic simulation results, based on many-body interatomic potentials, of the migration of vacancies, solute and self-interstitial atoms (SIA) in pure Fe and binary Fe-0.9 and 1.0 at.% Cu alloys. Cu diffusion occurs by a vacancy mechanism and the calculated Cu diffusivity is in good agreement with experimental data. Strain field interactions between the oversized substitutional Cu solute atoms and SIA and SIA clusters are predominantly repulsive and result in both a decreased activation energy and diffusion pre-factor for SIA and small (N < 5) SIA cluster migration, which occurs by three-dimensional motion. The Cu appears to enhance the reorientation of the SIA clusters to different <111> directions, as well as the transition from <110> to mobile <111> configurations. The migration behavior of …
Date: January 25, 2001
Creator: Marian, J.; Wirth, B. D.; Perlado, J. M.; Odette, G. R. & Diaz de la Rubia, T.
System: The UNT Digital Library
Beryllium Sampling and Analysis Within the DOE Complex and Opportunities for Standardization (open access)

Beryllium Sampling and Analysis Within the DOE Complex and Opportunities for Standardization

Since the U. S. Department of Energy (DOE) published the DOE Beryllium Rule (10 CFR 850) in 1999, DOE sites have been required to measure beryllium on air filters and wipes for worker protection and for release of materials from beryllium-controlled areas. Measurements in the nanogram range on a filter or wipe are typically required. Industrial hygiene laboratories have applied methods from various analytical compendia, and a number of issues have emerged with sampling and analysis practices. As a result, a committee of analytical chemists, industrial hygienists, and laboratory managers was formed in November 2003 to address the issues. The committee developed a baseline questionnaire and distributed it to DOE sites and other agencies in the U.S. and U.K. The results of the questionnaire are presented in this paper. These results confirmed that a wide variety of practices were in use in the areas of sampling, sample preparation, and analysis. Additionally, although these laboratories are generally accredited by the American Industrial Hygiene Association (AIHA), there are inconsistencies in performance among accredited labs. As a result, there are significant opportunities for development of standard methods that could improve consistency. The current availabilities and needs for standard methods are further discussed in …
Date: January 25, 2005
Creator: BRISSON, MICHAEL
System: The UNT Digital Library
Brilliant's 5th (open access)

Brilliant's 5th

Article about Brilliant Magazine's 5th anniversary celebration held at Pangaea in Austin, Texas, on January 24, 2008.
Date: January 25, 2008
Creator: unknown
System: The UNT Digital Library
A Case for Including Transactions in OpenMP (open access)

A Case for Including Transactions in OpenMP

Transactional Memory (TM) has received significant attention recently as a mechanism to reduce the complexity of shared memory programming. We explore the potential of TM to improve OpenMP applications. We combine a software TM (STM) system to support transactions with an OpenMP implementation to start thread teams and provide task and loop-level parallelization. We apply this system to two application scenarios that reflect realistic TM use cases. Our results with this system demonstrate that even with the relatively high overheads of STM, transactions can outperform OpenMP critical sections by 10%. Overall, our study demonstrates that extending OpenMP to include transactions would ease programming effort while allowing improved performance.
Date: January 25, 2010
Creator: Wong, M.; Bihari, B. L.; de Supinski, B. R.; Wu, P.; Michael, M.; Liu, Y. et al.
System: The UNT Digital Library
Chiral perturbation theory for the Wilson lattice action (open access)

Chiral perturbation theory for the Wilson lattice action

The authors extend chiral perturbation theory to include linear dependence on the lattice spacing a for the Wilson action. The perturbation theory is written as a double expansion in the small quark mass m{sub q} and lattice spacing a. They present formulae for the mass and decay constant of a flavor-non-singlet meson in this scheme to order a and m{sub q}{sup 2}. The extension to the partially quenched theory is also described.
Date: January 25, 2002
Creator: Rupak, Gautam & Shoresh, Noam
System: The UNT Digital Library
Commercial off the shelf (COTS) software in safety systems (open access)

Commercial off the shelf (COTS) software in safety systems

Many safety systems, such as those in nuclear power plants, are systems for which the consequences of failure can be severe or catastrophic. These systems must be developed, implemented, and maintained in ways that provide assurance that catastrophic consequences will be prevented. This paper discusses various aspects of the question of using commercially available software in these systems. Risk, grading, and system assessment are discussed, and relevant standards are summarized. Recommendations for addressing key issues are given.
Date: January 25, 1998
Creator: Scott, J.A. & Preckshot, G.G.
System: The UNT Digital Library
Comparison of Linac Simulation Codes (open access)

Comparison of Linac Simulation Codes

The Spallation Neutron Source (SNS) project is a collaborative effort between Brookhaven, Argonne, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge National Laboratories. Los Alamos is responsible for the design of the linac for this accelerator complex. The code PARMILA, developed at Los Alamos is widely used for proton linac design and beam dynamics studies. The most updated version includes superconducting structures among others. In recent years, some other codes have also been developed which primarily focuses on the studies of the beam dynamics. In this paper, we compare the simulation results and discuss physics aspects of the different linac design and beam dynamics simulation codes.
Date: January 25, 2001
Creator: Nath, S.; Ryne, Robert D.; Stovall, J.; Takeda, H.; Xiang, J.; Young, L. et al.
System: The UNT Digital Library
Computation at the edge of chaos: Phase transition and emergent computation (open access)

Computation at the edge of chaos: Phase transition and emergent computation

In order for computation to emerge spontaneously and become an important factor in the dynamics of a system, the material substrate must support the primitive functions required for computation: the transmission, storage, and modification of information. Under what conditions might we expect physical systems to support such computational primitives This paper presents research on Cellular Automata which suggests that the optimal conditions for the support of information transmission, storage, and modification, are achieved in the vicinity of a phase transition. We observe surprising similarities between the behaviors of computations and systems near phase-transitions, finding analogs of computational complexity classes and the Halting problem within the phenomenology of phase-transitions. We conclude that there is a fundamental connection between computation and phase-transitions, and discuss some of the implications for our understanding of nature if such a connection is borne out. 31 refs., 16 figs.
Date: January 25, 1990
Creator: Langton, C.
System: The UNT Digital Library
CONTAMINATED PROCESS EQUIPMENT REMOVAL FOR THE D&D OF THE 232-Z CONTAMINATED WASTE RECOVERY PROCESS FACILITY AT THE PLUTONIUM FINISHING PLANT (PFP) (open access)

CONTAMINATED PROCESS EQUIPMENT REMOVAL FOR THE D&D OF THE 232-Z CONTAMINATED WASTE RECOVERY PROCESS FACILITY AT THE PLUTONIUM FINISHING PLANT (PFP)

This paper describes the unique challenges encountered and subsequent resolutions to accomplish the deactivation and decontamination of a plutonium ash contaminated building. The 232-Z Contaminated Waste Recovery Process Facility at the Plutonium Finishing Plant was used to recover plutonium from process wastes such as rags, gloves, containers and other items by incinerating the items and dissolving the resulting ash. The incineration process resulted in a light-weight plutonium ash residue that was highly mobile in air. This light-weight ash coated the incinerator's process equipment, which included gloveboxes, blowers, filters, furnaces, ducts, and filter boxes. Significant airborne contamination (over 1 million derived air concentration hours [DAC]) was found in the scrubber cell of the facility. Over 1300 grams of plutonium held up in the process equipment and attached to the walls had to be removed, packaged and disposed. This ash had to be removed before demolition of the building could take place.
Date: January 25, 2007
Creator: Hopkins, A. M.; Minette, M. J. & Klos, D. B.
System: The UNT Digital Library
Continuum-based FEM modeling of ceramic powder compaction using a cap-plasticity constitutive model (open access)

Continuum-based FEM modeling of ceramic powder compaction using a cap-plasticity constitutive model

Common ceramic component manufacturing typically involves the processing of the raw materials in powder form. Granulated powder is formed into a green body of the desired size and shape by consolidation, often by simply pressing nominally dry powder. Ceramic powders are commonly pressed in steel dies or rubber bags with the aim of producing a near-net-shape green body for subsequent sintering. Density gradients in these compacts, introduced during the pressing operation, are often severe enough to cause distortions in the shape of the part during sintering due to nonuniform shrinkage. In such cases, green machining or diamond grinding operations may be needed to obtain the desired final shape and size part. In severe cases, nonuniform shrinkage may even cause fracture in the parts during sintering. Likewise, density gradients can result in green bodies that break during ejection from the die or that are too fragile to be handled during subsequent processing. Empirical relationships currently exist to describe powder compaction but provide little understanding of how to control die design or compaction parameters to minimize density gradients thereby forcing the designer to use expensive and time consuming trial and error procedures. For this reason, interest has grown in developing computational tools …
Date: January 25, 2000
Creator: Arguello, Jose G., Jr.; Fossum, Arlo F.; Zeuch, David H. & Ewsuk, Kevin G.
System: The UNT Digital Library
Contract reform: It`s working at Fernald (open access)

Contract reform: It`s working at Fernald

DOE`s contract reform initiatives at Fernald and the performance-based system DOE is now using to evaluate FERMCO are key elements to the current and future success of DOE and FERMCO at Fernald. Final cleanup of the Fernald site is planned for completion by 2005 per an accelerated 10-year remediation plan which has been approved by DOE and endorsed by the US EPA, Ohio EPA, and the Fernald Citizens Task Force. Required funding of approximately $276 million plus inflation annually for 10 years to accomplish final cleanup is now being considered by US Congress. Contract reform initiatives and modified performance measurement systems, along with best business practices, are clearing the path for the expedited cleanup of Fernald.
Date: January 25, 1996
Creator: Craig, J. & Hunt, A.
System: The UNT Digital Library
Copper-diamond composite substrates for electronic components (open access)

Copper-diamond composite substrates for electronic components

High-power density electronic components such as fast microprocessors and power semiconductors are often limited by inability to keep the device junctions below their max rated operating temperature. Present high power multichip module and single chip package designs use substrate materials such as Si nitride or copper tungsten with thermal conductivity in the range of 200 W/m{center_dot}K. We have developed a copper-diamond composite (Dymalloy) with a thermal conductivity of 420 W/m{center_dot}K, better than Cu, and an adjustable thermal expansion coefficient (TCE=5.5 ppM/C at 25 C), compatible with Si and GaAs. Because of the matched TCE, it is possible to use low thermal resistance hard die attach methods. The mechanical properties of the composite also make it attractive as an electronic component substrate material.
Date: January 25, 1995
Creator: Davidson, H.L.; Colella, N.J.; Kerns, J.A. & Makowiecki, D.
System: The UNT Digital Library
Cosmology and the S-matrix (open access)

Cosmology and the S-matrix

We study conditions for the existence of asymptotic observables in cosmology. With the exception of de Sitter space, the thermal properties of accelerating universes permit arbitrarily long observations, and guarantee the production of accessible states of arbitrarily large entropy. This suggests that some asymptotic observables may exist, despite the presence of an event horizon. Comparison with decelerating universes shows surprising similarities: Neither type suffers from the limitations encountered in de Sitter space, such as thermalization and boundedness of entropy. However, we argue that no realistic cosmology permits the global observations associated with an S-matrix.
Date: January 25, 2005
Creator: Bousso, Raphael
System: The UNT Digital Library
Coupled map lattice model of jet breakup (open access)

Coupled map lattice model of jet breakup

An alternative approach is described to evaluate the statistical nature of the breakup of shaped charge liners. Experimental data from ductile and brittle copper jets are analyzed in terms of velocity gradient, deviation of {Delta}V from linearity, R/S analysis, and the Hurst exponent within the coupled map lattice model. One-dimensional simulations containing 600 zones of equal mass and using distinctly different force-displacement curves are generated to simulate ductile and brittle behavior. A particle separates from the stretching jet when an element of material reaches the failure criterion. A simple model of a stretching rod using brittle, semi-brittle, and ductile force-displacement curves is in agreement with the experimental results for the Hurst exponent and the phase portraits and indicates that breakup is a correlated phenomenon.
Date: January 25, 2001
Creator: Minich, R W; Schwartz, A J & Baker, E L
System: The UNT Digital Library
Coupled THM analysis of the single-heater test at yucca mountain (open access)

Coupled THM analysis of the single-heater test at yucca mountain

This paper presents a summary of results from the Single-Heater Test (SHT) at Yucca Mountain, Nevada. In the SHT, a horizontal, 5-m-long, line-heat source was used to heat a rock pillar for nine months. Moisture movement was monitored during and after heating using electrical-resistance tomography (ERT) and neutron-logging techniques. Results indicate drying in regions of the rock where temperature reached 60°C and above. The drying zone is asymmetric and is not centered on the heater, but has lobes extending above and to the sides of the heater. Predicted temperatures agreed well with observations. A cold- trap effect was predicted, in the heater borehole, that efficiently transfers heat along the heater borehole to the excavation wall. A simple thermomechanical analysis of the SHT shows that shear zones predicted for vertical fractures coincide with regions of increased moisture content derived from ERT measurements.
Date: January 25, 1999
Creator: Blair, S. C.; Buscheck, T. A.; Daily, W. D.; Lin, W. & Ramirez, A. L.
System: The UNT Digital Library
Cultural and Social Factors in Care Delivery Among African American Caregivers of Persons With Dementia: A Scoping Review (open access)

Cultural and Social Factors in Care Delivery Among African American Caregivers of Persons With Dementia: A Scoping Review

Article asserts that cultural and social factors significantly influence the care provided to persons with dementia. This scoping review aimed to map emerging evidence on the influence of cultural and social factors on care delivery among Africa American caregivers of persons with dementia, especially during the COVID-19 pandemic.
Date: January 25, 2022
Creator: Imoh, Udoh Idorenyin & Charity, Tinofirei
System: The UNT Digital Library