The Castle Project (open access)

The Castle Project

The goal of the Castle project was to provide a parallel programming environment that enables the construction of high performance applications that run portably across many platforms. The authors approach was to design and implement a multilayered architecture, with higher levels building on lower ones to ensure portability, but with care taken not to introduce abstractions that sacrifice performance.
Date: February 16, 2000
Creator: Anderson, Tom; Culler, David; Demmel, James; Feldman, Jerry; Graham, Susan; Hilfinger, Paul et al.
Object Type: Report
System: The UNT Digital Library
Atmospheric Radiation Measurement Program Facilities Newsletter, January 2000 (open access)

Atmospheric Radiation Measurement Program Facilities Newsletter, January 2000

Monthly newsletter discussing news and activities related to the Atmospheric Radiation Measurement Program, articles about weather and atmospheric phenomena, and other related topics.
Date: February 16, 2000
Creator: Atmospheric Radiation Measurement Program (U.S.)
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Comparison of Variability of the Monthly Mean Temperature of the ECMWF and NCEP Reanalyses and CCM3 and DSM Simulations (open access)

Comparison of Variability of the Monthly Mean Temperature of the ECMWF and NCEP Reanalyses and CCM3 and DSM Simulations

The low frequency variation in the three dimensional air temperature fields of two reanalyses and two model simulations are described. The data sets used are the monthly mean temperature fields for the NCAR Climate Simulation Model (CSM, Boville and Gent, 1998) 300 year run, a NCAR Community Climate Model version 3 (CCM3, Kiehl et al., 1998) AMIP type simulation, and the NCEPLNCAR and ECMWF (ERA) reanalysis data sets. The variances and correlations are computed for the anomalies from the annual cycle for each data set. In general the reanalyses and models agree fairly well on the structure of the temperature variance. The models tend to have too much variance at the surface compared to the reanalyses. The CSM's poor simulation of the SST in the eastern Pacific leads to a much reduced variance in the Nino3 region. The enhanced variability over land appears to affect the midlatitude simulation of the CSM in that the higher surface variability extends off the east coast of continents. This is not evident in CCM3 and reanalyses where the SSTs are prescribed. At 200 hPa the CCM3 and reanalyses all evince the dumb bell pattern straddling the Equator in the eastern Pacific attributed by Yulaeva …
Date: February 16, 2000
Creator: Boyle, J.S.
Object Type: Report
System: The UNT Digital Library
The use of pressurized bladders for stress control of superconducting magnets (open access)

The use of pressurized bladders for stress control of superconducting magnets

None
Date: February 16, 2000
Creator: Caspi, S.; Gourlay, S.; Hafalia, R.; Lietzke, A.; O'Neill, J.; Taylor, C. et al.
Object Type: Article
System: The UNT Digital Library
Round Robin Study of Rotational Strain Rheometers (open access)

Round Robin Study of Rotational Strain Rheometers

A round robin of testing was performed to compare the performance of rotational dynamic mechanical spectrometers being used within the nuclear weapons complex. Principals from Sandia National Laboratories/New Mexico; Lockheed Martin Y12 Plant at Oak Ridge, Tennessee; Los Alamos National Laboratory, New Mexico (polycarbonate only); and Honeywell Federal Manufacturing and Technologies (FM and T), Kansas City, MO, performed identical testing of hydrogen blown polysiloxane S5370 and bisphenol-A polycarbonate. Over an oscillation frequency sweep from 0.01 Hz to 15.9 Hz at 135 C, each site produced shear storage modulus values with standard deviations of less than 5%. The data from Sandia, Y12, and Kansas City agreed to within 4%, while the Los Alamos data differed by as much as 13%. Storage modulus values for a frequency sweep of the S5370 at 35 C had standard deviations between 6% and 8%, and site-to-site agreement averaged 3%. The shear loss modulus values had standard deviations of 5%, 7%, and 52% for the sites participating, while the results differed by 12% on average.
Date: February 16, 2000
Creator: Clifford, M.J.
Object Type: Report
System: The UNT Digital Library
Design and performance of nitride-based UV LEDs (open access)

Design and performance of nitride-based UV LEDs

In this paper, the authors overview several of the critical materials growth, design and performance issues for nitride-based UV (< 400 nm) LEDs. The critical issue of optical efficiency is presented through temperature-dependent photoluminescence studies of various UV active regions. These studies demonstrate enhanced optical efficiencies for active regions with In-containing alloys (InGaN, AlInGaN). The authors discuss the trade-off between the challenging growth of high Al containing alloys (AlGaN, AlGaInN), and the need for sufficient carrier confinement in UV heterostructures. Carrier leakage for various composition AlGaN barriers is examined through a calculation of the total unconfined carrier density in the quantum well system. They compare the performance of two distinct UV LED structures: GaN/AlGaN quantum well LEDs for {lambda}< 360 nm emission, and InGaN/AlGaInN quantum well LEDs for 370 nm <{lambda}< 390 nm emission.
Date: February 16, 2000
Creator: Crawford, Mary H.; Han, Jung; Chow, Weng W.; Banas, Michael Anthony; Figiel, Jeffery J.; Zhang, Lei et al.
Object Type: Article
System: The UNT Digital Library
Solute Transport in Variable Aperture Fractures: An Investigation of the Relative Importance of Taylor Dispersion and Macrodispersion (open access)

Solute Transport in Variable Aperture Fractures: An Investigation of the Relative Importance of Taylor Dispersion and Macrodispersion

None
Date: February 16, 2000
Creator: Detwiler, Russell L.; Rajaram, Harihar & Glass, Robert J., Jr.
Object Type: Article
System: The UNT Digital Library
Environmental Management Performance Report for December 1999 (open access)

Environmental Management Performance Report for December 1999

The purpose of the Environmental Management Performance Report (EMPR) is to provide the Department of Energy Richland Operations Office's (DOE-RL's) report of Hanford's Environmental Management (EM) performance by: U. S. Department of Energy, Richland Operations Office, Project Hanford Management Contract (PHMC) through Fluor Hanford, Inc. (FHI) and its subcontractors, Environmental Restoration Contract through Bechtel Hanford, Inc. (BHI), and its subcontractors, and Pacific Northwest National Laboratories (PNNL) for EM and EM Science and Technology (S&T) Mission. This report is a monthly publication that summarizes EM Site performance under RL Operations Office. It is organized by the four sections listed above, with each section containing an Executive Summary and Area Performance Summaries. A listing of what is contained in the sections can be found in the Table of Contents.
Date: February 16, 2000
Creator: EDER, D.M.
Object Type: Report
System: The UNT Digital Library
RADIANT Liquid Isotope Intravascular Radiation Therapy System (open access)

RADIANT Liquid Isotope Intravascular Radiation Therapy System

None
Date: February 16, 2000
Creator: Eigler, N.; Whiting, J.; Makkar, R.A.J.; Honda, H.; Knapp, F.F.; Litvack, F. et al.
Object Type: Article
System: The UNT Digital Library
Micromechanical characterization tools for highly-filled polymers (open access)

Micromechanical characterization tools for highly-filled polymers

We are attempting to characterize and model the micromechanical response of highly-filled polymers. In this class of materials, the continuous plastic binder used to bond the highly-filled material dominates the observed viscoelastic response. As a result, realistic lifetime analysis of these materials will require a thorough understanding of the contribution of the plastic binder. Laboratory applications of these materials include plastic bonded explosives, propellants, a variety of specialized filled organic materials for stockpile systems, and highly filled epoxy dielectric materials for the National Ignition Facility. We have explored numerous techniques to characterize the local microstructure of plastic bonded explosives. However, insufficient funding was obtained to bring these technologies to maturity, nevertheless our present tool set is significantly better than 2 years ago. We have also made some progress in developing an appropriate micromechanical constitutive modeling framework, based on a finite element method incorporating a cohesive zone model to represent the binder contribution within a Voronoi tesselation mesh structure for the PBX grains. A second modeling approach was used to incorporate analytical micromechanics (generalized self-consistent schemes). However, preliminary theoretical analysis strongly suggested that this approach would be invalid for such extremely high-filled systems like PBX.
Date: February 16, 2000
Creator: Groves, S; DeTeresa, S; Cunningham, B; Ciarlo, D; Allen, D; Clayton, K et al.
Object Type: Report
System: The UNT Digital Library
Shape reversal of Ge/Si domes to pyramids via Si-Ge intermixing and strain reduction (open access)

Shape reversal of Ge/Si domes to pyramids via Si-Ge intermixing and strain reduction

At 650 C, Si freely intermixes with Ge in the dome islands causing a reduction in the strain of the islands and an increase in island size. The shape reversal of Ge/Si domes to pyramids is investigated by analysis of the strain and size changes that occur on an island by island basis. This was carried out for anneal times of 0, 20, 40 and 60 minutes. Transition islands were observed consistent with previous work, which are partially domes and partially pyramids. These islands demonstrated a strain gradient, having a slightly lower strain on the side that has transformed to a pyramid. Cross-sectional STEM was then used to show that this strain gradient is associated with a non-uniform Si intermixing in the islands.
Date: February 16, 2000
Creator: Henstrom, W. L.; Liu, C.-P. & Gibson, J. M.
Object Type: Article
System: The UNT Digital Library
Defining, expressing, and using context in a simulation environment (open access)

Defining, expressing, and using context in a simulation environment

Reuse and interoperability are two keywords in the mantra of the modeling and simulation community. In order to achieve these goals, one must be able to capture, express, and manage the context of individual entities, models, and applications. Capturing the context requires having a thorough understanding of what the entity, model, or application was intended to do and is able to do. While many aspects of context are not easily expressible in a format or language that could be understood and managed in a simulation environment, there are some aspects that can be and the authors discuss how these aspects can be represented in a generalized object-oriented framework.
Date: February 16, 2000
Creator: Hummel, J. R. & Christiansen, J. H.
Object Type: Article
System: The UNT Digital Library
Thermal degradation of M41S-class mesoporous sieves as revealed by small angle X-ray scattering (open access)

Thermal degradation of M41S-class mesoporous sieves as revealed by small angle X-ray scattering

The authors have studied the temperature stability of M41S class siliceous mesoporous materials loaded with carbonaceous material by temperature programmed small-angle X-ray scattering (TPSAXS) techniques. Results show the thermal structural instability of large pore pure silica sieve material with carbonaceous material (such as coal extracts) occluded within the pores of mesoporous 31 {angstrom} M41S materials. Unfilled pore M41S materials do not show thermal-related structural instability.
Date: February 16, 2000
Creator: Hunt, J. E.; Xu, L.; Winans, R. E. & Seifert, S.
Object Type: Article
System: The UNT Digital Library
Production and Availability of Beta-Emitting Radioisotopes for Restenosis Therapy (open access)

Production and Availability of Beta-Emitting Radioisotopes for Restenosis Therapy

None
Date: February 16, 2000
Creator: Knapp, F. F. Jr.
Object Type: Article
System: The UNT Digital Library
Scientific Software Component Technology (open access)

Scientific Software Component Technology

We are developing new software component technology for high-performance parallel scientific computing to address issues of complexity, re-use, and interoperability for laboratory software. Component technology enables cross-project code re-use, reduces software development costs, and provides additional simulation capabilities for massively parallel laboratory application codes. The success of our approach will be measured by its impact on DOE mathematical and scientific software efforts. Thus, we are collaborating closely with library developers and application scientists in the Common Component Architecture forum, the Equation Solver Interface forum, and other DOE mathematical software groups to gather requirements, write and adopt a variety of design specifications, and develop demonstration projects to validate our approach. Numerical simulation is essential to the science mission at the laboratory. However, it is becoming increasingly difficult to manage the complexity of modern simulation software. Computational scientists develop complex, three-dimensional, massively parallel, full-physics simulations that require the integration of diverse software packages written by outside development teams. Currently, the integration of a new software package, such as a new linear solver library, can require several months of effort. Current industry component technologies such as CORBA, JavaBeans, and COM have all been used successfully in the business domain to reduce software development …
Date: February 16, 2000
Creator: Kohn, S.; Dykman, N.; Kumfert, G. & Smolinski, B.
Object Type: Report
System: The UNT Digital Library
``In-situ'' spectro-electrochemical studies of radionuclide-contaminated surface films on metals (open access)

``In-situ'' spectro-electrochemical studies of radionuclide-contaminated surface films on metals

The incorporation of heavy metal ions and radioactive contaminants into hydrous oxide films has been investigated in order to provide fundamental knowledge that could lead to the technological development of cost-effective processes and techniques for the decontamination of storage tanks, piping systems, surfaces, etc., in DOE nuclear facilities. The formation of oxide/hydroxide films was simulated by electrodeposition onto a graphite substrate from solutions of the appropriate metal salt. Synchrotron X-ray Absorption Spectroscopy (XAS), supplemented by Laser Raman Spectroscopy (LRS), was used to determine the structure and composition of the host oxide film, as well as the impurity ion. Results have been obtained for the incorporation of Ce, Sr, Cr, Fe, and U into hydrous nickel oxide films. Ce and Sr oxides/hydroxides are co-precipitated with the nickel oxides in separate phase domains. Cr and Fe, on the other hand, are able to substitute into Ni lattice sites or intercalate in the interlamellar positions of the brucite structure of Ni(OH){sub 2}. U was found to co-deposit as a U(VI) hydroxide. The mode of incorporation of metal ions depends both on the size and charge of the metal ion. The structure of iron oxide (hydroxide) films prepared by both anodic and cathodic deposition …
Date: February 16, 2000
Creator: Melendres, C. A.; Mini, S. & Mansour, A. N.
Object Type: Report
System: The UNT Digital Library
Factors controlling satiated relative permeability in a partially-saturated horizontal fracture (open access)

Factors controlling satiated relative permeability in a partially-saturated horizontal fracture

Recent work demonstrates that phase displacements within horizontal fractures large with respect to the spatial correlation length of the aperture field lead to a satiated condition that constrains the relative permeability to be less than one. The authors use effective media theory to develop a conceptual model for satiated relative permeability, then compare predictions to existing experimental measurements, and numerical solutions of the Reynolds equation on the measured aperture field within the flowing phase. The close agreement among all results and data show that for the experiments considered here, in-plane tortuosity induced by the entrapped phase is the dominant factor controlling satiated relative permeability. They also find that for this data set, each factor in the conceptual model displays an approximate power law dependence on the satiated saturation of the fracture.
Date: February 16, 2000
Creator: Nicholl, M. J.; Rajaram, H. & Glass Jr.,Robert J.
Object Type: Article
System: The UNT Digital Library
Automated Synthesis of Highly Concentrated Re-188-MAG3 for Intracoronary Radiation Therapy (open access)

Automated Synthesis of Highly Concentrated Re-188-MAG3 for Intracoronary Radiation Therapy

None
Date: February 16, 2000
Creator: Oh, S.; Moon, D.; Park, S.-W.; Hong, M.-K.; Park, S.-J.; Knapp, F.F. et al.
Object Type: Article
System: The UNT Digital Library
Generic Test Plan for Solubility Screening Tests of Hanford Tank Waste (open access)

Generic Test Plan for Solubility Screening Tests of Hanford Tank Waste

Waste pretreatment and immobilization requires the tank waste to be retrieved. Retrieval from tanks may require dilution. This test determines the effects of dilution on the mass of solids and their composition. This test plan gives test instructions, example data sheets, a waste compatibility review, and a waste stream fact sheet.
Date: February 16, 2000
Creator: PERSON, J.C.
Object Type: Report
System: The UNT Digital Library
Time Deployment Study for Annulus Pumping (open access)

Time Deployment Study for Annulus Pumping

Radioactive wastes from processing irradiated uranium fuels have been stored as alkaline slurries in underground tanks at the Hanford Site. Single-shell tanks (SST) and double-shell tanks (DST) of various sizes were used for waste storage. Of the total 177 tanks, there are 28 DSTs. DSTs are located in AN, AP, AW, AY, AZ, and SY tank farms in the 200 East (200E) and 200-West (200W) Areas. The storage capacities of the DSTs vary from 980,000 to 1,140,000 gal. DSTs are designed and constructed as an integral steel structure, i.e., an inner shell within an outer shell, so that any leak from the inner shell is confined within the annulus without impacting the environment. The inner shell provides primary containment for the wastes and the outer shell provides secondary containment in the form of an annulus. The annulus of a DST is equipped with a pump pit, leak detection probes, and other accessories. The existing annulus pumps in the DSTs need to be revamped with a new system to reduce operating costs and reduce the time to deploy a pumping system. The new pumping system will minimize the likelihood of a release of waste into the environment; improve capability of waste …
Date: February 16, 2000
Creator: REBERGER, D.W.
Object Type: Report
System: The UNT Digital Library
Method of making steel strapping and strip (open access)

Method of making steel strapping and strip

The technical progress obtained for this time frame consisted of the awarding of two contracts for determination of metallurgical parameters for heat treatment of strapping and strip which are unavailable from current technology and/or published data in this field. The two contractors were Bricmont, Inc. and the Department of Materials Science and Engineering at the Technological Institute of Northwestern University, Evanston, IL. Phase 1 of the two stage contract with Bricmont, Inc. which provided a computer analysis of the cooling rates of a typical range of thickness' of strapping was completed. This study was developed for the purpose of determining the time parameters for quenching low carbon steels to a martensitic microstructure within the time frame of the design of the proposed process. It also provides design criteria for cooling to ambient for the total process. This data is required for Phase 2 of the Bricmont proposal which completes the design and specifications of the total heat treating and cooling system for the process. This becomes the basis for developing the cost and space requirements for this component of the production line. The authors do not intend to award Phase 2 until the work done at Northwestern University discussed hereafter …
Date: February 16, 2000
Creator: Reilly, Robert D.
Object Type: Report
System: The UNT Digital Library
Simple shearing flow of dry soap foams with TCP structure[Tetrahedrally Close-Packed] (open access)

Simple shearing flow of dry soap foams with TCP structure[Tetrahedrally Close-Packed]

The microrheology of dry soap foams subjected to large, quasistatic, simple shearing deformations is analyzed. Two different monodisperse foams with tetrahedrally close-packed (TCP) structure are examined: Weaire-Phelan (A15) and Friauf-Laves (C15). The elastic-plastic response is evaluated by calculating foam structures that minimize total surface area at each value of strain. The minimal surfaces are computed with the Surface Evolver program developed by Brakke. The foam geometry and macroscopic stress are piecewise continuous functions of strain. The stress scales as T/V{sup 1/3} where T is surface tension and V is cell volume. Each discontinuity corresponds to large changes in foam geometry and topology that restore equilibrium to unstable configurations that violate Plateau's laws. The instabilities occur when the length of an edge on a polyhedral foam cell vanishes. The length can tend to zero smoothly or abruptly with strain. The abrupt case occurs when a small increase in strain changes the energy profile in the neighborhood of a foam structure from a local minimum to a saddle point, which can lead to symmetry-breaking bifurcations. In general, the new foam topology associated with each stable solution branch results from a cascade of local topology changes called T1 transitions. Each T1 cascade produces …
Date: February 16, 2000
Creator: Reinelt, Douglas A. & Kraynik, Andrew M.
Object Type: Article
System: The UNT Digital Library
Estimates of Particulate Mass in Multi Canister Overpacks (MCO) (open access)

Estimates of Particulate Mass in Multi Canister Overpacks (MCO)

High, best estimate, and low values are developed for particulate inventories within MCO baskets that have been loaded with freshly cleaned fuel assemblies and scrap. These per-basket estimates are then applied to all anticipated MCO payload configurations to identify which configurations are bounding for each type of particulate. Finally the resulting bounding and nominal values for residual particulates are combined with corresponding values [from other documents] for particulates that may be generated by corrosion of exposed uranium after the fuel has been cleaned. The resulting rounded nominal estimate for a typical MCO after 40 years of storage is 8 kg. The estimate for a bounding total particulate case MCO is that it may contain up to 64 kg of particulate after 40 years of storage.
Date: February 16, 2000
Creator: Sloughter, J. P.
Object Type: Report
System: The UNT Digital Library
Growing plants on atoll soils (open access)

Growing plants on atoll soils

Many years ago people living on atolls depended entirely on foods gathered from the sea and reefs and grown on land. Only a few plants, such as coconut (ni), Pandanus (bob), and arrowroot (mok-mok), could be grown on the lower rainfall atolls, although adequate groundwater conditions also allowed taro (iaraj, kotak, wot) to be cultivated. On higher rainfall atolls, breadfruit (ma) was a major food source, and banana (binana, kepran), lime (laim), and taros (iaraj, kotak, wot) could be grown. The early atoll populations were experts in growing plants that were vital to sustaining their nutrition requirements and to providing materials for thatch, basketry, cordage, canoe construction, flowers, and medicine. They knew which varieties of food plants grew well or poorly on their atolls, how to propagate them, and where on their atoll they grew best. They knew the uses of most native plants and what the various woods were well suited for. Many varieties of Pandanus (bob) and breadfruit (ma) grew well with high rainfall, but only a few produced well on drier atolls. Such information had been passed down through the generations although some of it has been lost in the last century. Today there are new plants …
Date: February 16, 2000
Creator: Stone, E L; Migvar, L & Robison, W L
Object Type: Report
System: The UNT Digital Library