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Chiral Invariant Phase Space Event Generator: III. Modeling of real and virtual photon interactions with nuclei below pion production threshold (open access)

Chiral Invariant Phase Space Event Generator: III. Modeling of real and virtual photon interactions with nuclei below pion production threshold

Nuclear fragment production in photonuclear reactions below pion production threshold is implemented in the developed version of the new event generator, based on the CHIPS model, within the GEANT4 simulation toolkit. The spectra of secondary nucleons in the photonuclear process are compared with experimental data.
Date: May 1, 2000
Creator: Degtyarenko, P.V.; Kossov, M.V. & Wellisch, H.-P.
Object Type: Article
System: The UNT Digital Library
Neutron Total Cross Sections of {sup 235}U From Transmission Measurements in the Energy Range 2 keV to 300 keV and Statistical Model Analysis of the Data (open access)

Neutron Total Cross Sections of {sup 235}U From Transmission Measurements in the Energy Range 2 keV to 300 keV and Statistical Model Analysis of the Data

The average {sup 235}U neutron total cross sections were obtained in the energy range 2 keV to 330 keV from high-resolution transmission measurements of a 0.033 atom/b sample.1 The experimental data were corrected for the contribution of isotope impurities and for resonance self-shielding effects in the sample. The results are in very good agreement with the experimental data of Poenitz et al.4 in the energy range 40 keV to 330 keV and are the only available accurate experimental data in the energy range 2 keV to 40 keV. ENDF/B-VI evaluated data are 1.7% larger. The SAMMY/FITACS code 2 was used for a statistical model analysis of the total cross section, selected fission cross sections and data in the energy range 2 keV to 200 keV. SAMMY/FITACS is an extended version of SAMMY which allows consistent analysis of the experimental data in the resolved and unresolved resonance region. The Reich-Moore resonance parameters were obtained 3 from a SAMMY Bayesian fits of high resolution experimental neutron transmission and partial cross section data below 2.25 keV, and the corresponding average parameters and covariance data were used in the present work as input for the statistical model analysis of the high energy range of …
Date: May 1, 2000
Creator: Derrien, H.; Harvey, J. A.; Larson, N. M.; Leal, L. C. & Wright, R. Q.
Object Type: Report
System: The UNT Digital Library
Revealing myths about people, energy and buildings (open access)

Revealing myths about people, energy and buildings

In this essay we take a closer look at some energy myths, focusing on the ways energy professionals and the public alike, talk, write and teach about how energy affects the way in which we design, operate, retrofit and inhabit buildings. What myths about people, energy and buildings are current today? Who tells these myths and why do we believe them? How do myths affect our behavior? Myths are a way of understanding the world we live in. They may represent incomplete understanding, or be based on premises that are scientifically not valid, but they help us understand and explain how the world works, and we shape our behavior accordingly.
Date: May 1, 2000
Creator: Diamond, R. & Moezzi, M.
Object Type: Article
System: The UNT Digital Library
Developing a cost effective environmental solution for produced water and creating a ''new'' water resource (open access)

Developing a cost effective environmental solution for produced water and creating a ''new'' water resource

The project goal is to convert a currently usable by-product of oil production, produced water, into a valuable drinking water resource. The project was located at the Placate Oil Field in Santa Clarita, California, approximately 25 miles north of Los Angeles. The project included a literature review of treatment technologies; preliminary bench-scale studies to refine a planning level cost estimate; and a 10-100 gpm pilot study to develop the conceptual design and cost estimate for a 44,000 bpd treatment facility. A reverse osmosis system was constructed, pilot tested, and the data used to develop a conceptual design and operation of four operational scenarios, two industrial waters levels and two irrigation/potable water.
Date: May 1, 2000
Creator: Doran, Glenn & Leong, Lawrence Y.C.
Object Type: Report
System: The UNT Digital Library
Evaluation of Elevated Tritium Levels in Groundwater Downgradient from the 618-11 Burial Ground Phase I Investigations (open access)

Evaluation of Elevated Tritium Levels in Groundwater Downgradient from the 618-11 Burial Ground Phase I Investigations

This report describes the results of the preliminary investigation of elevated tritium in groundwater discovered near the 618-11 burial ground, located in the eastern part of the Hanford Site. Tritium in one well downgradient of the burial ground was detected at levels up to 8,140,000 pCi/L. The 618-11 burial ground received a variety of radioactive waste from the 300 Area between 1962 and 1967. The burial ground covers 3.5 hectare (8.6 acre) and contains trenches, large diameter caissons, and vertical pipe storage units. The burial ground was stabilized with a native sediment covering. The Energy Northwest reactor complex was constructed immediately east of the burial ground.
Date: May 1, 2000
Creator: Dresel, P. E.; Smith, R. M.; Williams, B. A.; Thompson, C. J.; Evans, J. C. & Hulstrom, L. C.
Object Type: Report
System: The UNT Digital Library
Examination of 304L stainless steel to 6061-T6 aluminum inertia welded transition joints after irradiation in a spallation neutron spectrum (open access)

Examination of 304L stainless steel to 6061-T6 aluminum inertia welded transition joints after irradiation in a spallation neutron spectrum

None
Date: May 1, 2000
Creator: Dunn, K.
Object Type: Article
System: The UNT Digital Library
OPTIMIZATION OF THE CATHODE LONG TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING (open access)

OPTIMIZATION OF THE CATHODE LONG TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING

The cathode materials for molten carbonate fuel cells (MCFCs) must have low dissolution rate, high structural strength and good electrical conductivity. Currently available cathodes are made of lithiated NiO which have acceptable structural strength and conductivity. However a study carried out by Orfeld et al. and Shores et al. indicated that the nickel cathodes dissolved, then precipitated and reformed as dendrites across the electrolyte matrix. This results in a decrease in cell utilization and eventually leads to shorting of the cell. The solubility of NiO was found to depend upon the acidity/basicity of the melt (basicity is directly proportional to log P{sub CO2}), carbonate composition, H{sub 2}O partial pressure and temperature. Urushibata et al. found that the dissolution of the cathode is a primary life limiting constraint of MCFCs, particularly in pressurized operation. With currently available NiO cathodes, the goal of 40,000 hours for the lifetime of MCFC appears achievable with cell operation at atmospheric pressure. However, the cell life at 10 atm and higher cell pressures is in the range between 5,000 to 10,000 hours. The overall objective of this research is to develop a superior cathode for MCFC's with improved catalytic ability, enhanced corrosion resistance with low ohmic …
Date: May 1, 2000
Creator: Durairajan, Anand; Haran, Bala; Popov, Branko N. & White, Ralph E.
Object Type: Report
System: The UNT Digital Library
Environmental Management Performance Report May 2000 (open access)

Environmental Management Performance Report May 2000

The purpose of this report is to provide the Department of Energy Richland Operations Office (DOE-FU) a report of the Project Hanford Management Contractors' (PHMC)' Environmental Management (EM) performance by Fluor Hanford (FH) and its subcontractors. This report is a monthly publication that summarizes the PHMC EM performance. In addition, it includes some PHMC-level data not detailed elsewhere in the report. Section A, Executive Summary, provides an executive level summary of the cost, schedule, and technical performance described in this report. It summarizes performance for the period covered, highlights areas worthy of management attention, and provides a forward look to some of the upcoming key performance activities as extracted from the PHMC baseline. The remaining sections provide detailed performance data relative to each individual Project (e.g., Waste Management, Spent Nuclear Fuels, etc.), in support of Section A of the report. A glossary of terms is provided at the end of this report for reference purposes. Unless otherwise noted, the Safety, Conduct of Operations, Metrics, and Cost/Schedule data contained herein is as of March 31, 2000. All other information is updated as noted.
Date: May 1, 2000
Creator: EDER, D.M.
Object Type: Report
System: The UNT Digital Library
Domain wall fermions with exact chiral symmetry (open access)

Domain wall fermions with exact chiral symmetry

The authors show how the standard domain wall action can be simply modified to allow arbitrarily exact chiral symmetry at finite fifth dimensional extent. They note that the method can be used for both quenched and dynamical calculations. They test the method using smooth and thermalized gauge field configurations. They also make comparisons of the performance (cost) of the domain wall operator for spectroscopy compared to other methods such as the overlap-Dirac operator and find both methods are comparable in cost.
Date: May 1, 2000
Creator: Edwards, Robert G. & Heller, Urs M.
Object Type: Article
System: The UNT Digital Library
Refinement and implementation of calibrated convection representation for use in global climate models. Final technical report (open access)

Refinement and implementation of calibrated convection representation for use in global climate models. Final technical report

None
Date: May 1, 2000
Creator: Emanuel, Kerry A.
Object Type: Report
System: The UNT Digital Library
Investigation of the impact of cleaning on the adhesive bond and the process implications (open access)

Investigation of the impact of cleaning on the adhesive bond and the process implications

While surface cleaning is the most common process step in DOE manufacturing operations, the link between a successful adhesive bond and the surface clean performed before adhesion is not well understood. An innovative approach that combines computer modeling expertise, fracture mechanics understanding, and cleaning experience to address how to achieve a good adhesive bond is discussed here to develop a capability that would result in reduced cleaning development time and testing, improved bonds, improved manufacturability, and even an understanding that leads to improved aging. A simulation modeling technique, polymer reference interaction site model applied near wall (Wall PRISM), provided the capability to include contaminants on the surface. Calculations determined an approximately 8% reduction in the work of adhesion for 1% by weight of ethanol contamination on the structure of a silicone adhesive near a surface. The demonstration of repeatable coatings and quantitative analysis of the surface for deposition of controlled amounts of contamination (hexadecane and mineral oil) was based on three deposition methods. The effect of the cleaning process used on interfacial toughness was determined. The measured interfacial toughness of samples with a Brulin cleaned sandblasted aluminum surface was found to be {approximately} 15% greater than that with a TCE …
Date: May 1, 2000
Creator: Emerson, John A.; Guess, Tommy R.; Adkins, Carol L. Jones; Curro, John G.; Reedy, Earl David, Jr.; Lopez, Edwin P. et al.
Object Type: Report
System: The UNT Digital Library
Improvements in the modelling of the recrystallization textures of Al-alloys (open access)

Improvements in the modelling of the recrystallization textures of Al-alloys

None
Date: May 1, 2000
Creator: Engler, O.
Object Type: Article
System: The UNT Digital Library
Radiative corrections for (e,e{prime}p) reactions at GeV energies (open access)

Radiative corrections for (e,e{prime}p) reactions at GeV energies

A general framework for applying radiative corrections to (e,e{prime}p) coincidence reactions at GeV energies is presented, with special emphasis to higher-order Bremsstrahlung effects, radiation from the scattered hadron, and the validity of peaking approximations. The sensitivity to the assumptions made in practically applying radiative corrections to (e,e{prime}p) data is extensively discussed. The general framework is tested against experimental data of the {sup 1}H(e,e{prime}p) reaction at momentum transfer values larger than 1.0 (GeV/c){sup 2}, where radiative processes become a dominant source of uncertainty. The formulas presented here can easily be modified for any other electron-induced coincidence reaction.
Date: May 1, 2000
Creator: Ent, R.; Filippone, B. W.; Makins, N. C. R.; Milner, R. G.; O'Neill, T. G. & Wasson, D. A.
Object Type: Article
System: The UNT Digital Library
South Texas Catholic Monthly (Corpus Christi, Tex.), Vol. 35, No. 6, Ed. 1 Monday, May 1, 2000 (open access)

South Texas Catholic Monthly (Corpus Christi, Tex.), Vol. 35, No. 6, Ed. 1 Monday, May 1, 2000

Monthly newspaper from Corpus Christi, Texas published by the Diocese of Corpus Christi that includes news of interest to Diocese members along with advertising.
Date: May 1, 2000
Creator: Espitia, Paula
Object Type: Newspaper
System: The Portal to Texas History
Integration of TGS and CTEN assays using the CTEN{_}FIT analysis and databasing program (open access)

Integration of TGS and CTEN assays using the CTEN{_}FIT analysis and databasing program

The CTEN{_}FIT program, written for Windows 9x/NT in C++, performs databasing and analysis of combined thermal/epithermal neutron (CTEN) passive and active neutron assay data and integrates that with isotopics results and gamma-ray data from methods such as tomographic gamma scanning (TGS). The binary database is reflected in a companion Excel database that allows extensive customization via Visual Basic for Applications macros. Automated analysis options make the analysis of the data transparent to the assay system operator. Various record browsers and information displays simplified record keeping tasks.
Date: May 1, 2000
Creator: Estep, R.
Object Type: Report
System: The UNT Digital Library
Step- vs. kink-formation energies on Pt(111) (open access)

Step- vs. kink-formation energies on Pt(111)

Ab-initio kink-formation energies are about 0.25 and 0.18 eV on the (100)- and (111)-microfacet steps of Pt(111), while the sum of the step-formation energies is 0.75 eV/atom. These results imply a specific ratio of formation energies for the two step types, namely 1.14, in excellent agreement with experiment. If kink-formation costs the same energy on the two step types, an inference recently drawn from scanning probe observations of step wandering, this ratio ought to be 1.
Date: May 1, 2000
Creator: FEIBELMAN,PETER J.
Object Type: Article
System: The UNT Digital Library
Materials Issues for Micromachines Development - ASCI Program Plan (open access)

Materials Issues for Micromachines Development - ASCI Program Plan

This report summarizes materials issues associated with advanced micromachines development at Sandia. The intent of this report is to provide a perspective on the scope of the issues and suggest future technical directions, with a focus on computational materials science. Materials issues in surface micromachining (SMM), Lithographic-Galvanoformung-Abformung (LIGA: lithography, electrodeposition, and molding), and meso-machining technologies were identified. Each individual issue was assessed in four categories: degree of basic understanding; amount of existing experimental data capability of existing models; and, based on the perspective of component developers, the importance of the issue to be resolved. Three broad requirements for micromachines emerged from this process. They are: (1) tribological behavior, including stiction, friction, wear, and the use of surface treatments to control these, (2) mechanical behavior at microscale, including elasticity, plasticity, and the effect of microstructural features on mechanical strength, and (3) degradation of tribological and mechanical properties in normal (including aging), abnormal and hostile environments. Resolving all the identified critical issues requires a significant cooperative and complementary effort between computational and experimental programs. The breadth of this work is greater than any single program is likely to support. This report should serve as a guide to plan micromachines development at Sandia.
Date: May 1, 2000
Creator: Fang, Huei Eliot; Battaile, Corbett C.; Benavides, Gilbert L.; Ensz, Mark T.; Buchheit, Thomas E.; LaVan, David A. et al.
Object Type: Report
System: The UNT Digital Library
Composite Resonator Surface Emitting Lasers (open access)

Composite Resonator Surface Emitting Lasers

The authors have developed electrically-injected coupled-resonator vertical-cavity lasers and have studied their novel properties. These monolithically grown coupled-cavity structures have been fabricated with either one active and one passive cavity or with two active cavities. All devices use a selectively oxidized current aperture in the lower cavity, while a proton implant was used in the active-active structures to confine current in the top active cavity. They have demonstrated optical modulation from active-passive devices where the modulation arises from dynamic changes in the coupling between the active and passive cavities. The laser intensity can be modulated by either forward or reverse biasing the passive cavity. They have also observed Q-switched pulses from active-passive devices with pulses as short as 150 ps. A rate equation approach is used to model the Q-switched operation yielding good agreement between the experimental and theoretical pulseshape. They have designed and demonstrated the operation of active-active devices which la.se simultaneously at both longitudinal cavity resonances. Extremely large bistable regions have also been observed in the light-current curves for active-active coupled resonator devices. This bistability can be used for high contrast switching with contrast ratios as high as 100:1. Coupled-resonator vertical-cavity lasers have shown enhanced mode selectivity which …
Date: May 1, 2000
Creator: Fischer, Arthur J.; Choquette, Kent D.; Chow, Weng W.; Allerman, Andrew A. & Geib, Kent M.
Object Type: Report
System: The UNT Digital Library
Structure and dynamics in low-dimensional guest-host systems (open access)

Structure and dynamics in low-dimensional guest-host systems

This is the final report of the fourth of four three year grants of the same title. The program evolved from an earlier DOE grant on graphite intercalation compounds. Since its inception eight years ago, the focus evolved continuously from conjugated polymers to fullerenes, disordered carbons for Li-ion battery applications, and most recently carbon nanotubes, with side excursion back to GIC's to exploit a recent advance in synthesis of a potentially exciting new phase. The unifying themes are the versatility of carbon in forming novel solids, and the flexibility of intercalation chemistry to provide new materials with potentially useful properties.
Date: May 1, 2000
Creator: Fischer, John E.
Object Type: Report
System: The UNT Digital Library
Rapid measurements and mapping of tracer gas concentrations in a large indoor space (open access)

Rapid measurements and mapping of tracer gas concentrations in a large indoor space

None
Date: May 1, 2000
Creator: Fischer, Marc L.; Price, Phillip N.; Thatcher, Tracy L.; Schwalbe, Carrie A.; Craig, Mathias J.; Wood, Emily E. et al.
Object Type: Article
System: The UNT Digital Library
Corrective Action Plan for Corrective Action Unit 407: Roller Coaster RADSAFE Area, Tonopah Test Range, Nevada (open access)

Corrective Action Plan for Corrective Action Unit 407: Roller Coaster RADSAFE Area, Tonopah Test Range, Nevada

This Corrective Action Plan (CAP) has been prepared for the Roller Coaster RADSAFE Area Corrective Action Unit 407 in accordance with the Federal Facility and Consent Order (Nevada Division of Environmental Protection [NDEP] et al., 1996). This CAP provides the methodology for implementing the approved Corrective Action Alternative as listed in the Corrective Action Decision Document (U.S. Department of Energy, Nevada Operations Office, 1999). The RCRSA was used during May and June of 1963 to decontaminate vehicles, equipment, and personnel from the Clean Slate tests. The Constituents of Concern (COCs) identified during the site characterization include plutonium, uranium, and americium. No other COCS were identified. The following closure actions will be implemented under this plan: (1) Remove and dispose of surface soils which are over three times background for the area. Soils identified for removal will be disposed of at an approved disposal facility. Excavated areas will be backfilled with clean borrow soil fi-om a nearby location. (2) An engineered cover will be constructed over the waste disposal pit area where subsurface COCS will remain. (3) Upon completion of the closure and approval of the Closure Report by NDEP, administrative controls, use restrictions, and site postings will be used to …
Date: May 1, 2000
Creator: Fitzmaurice, T. M.
Object Type: Report
System: The UNT Digital Library
Geomechanical modeling of reservoir compaction, surface subsidence, and casing damage at the Belridge diatomite field (open access)

Geomechanical modeling of reservoir compaction, surface subsidence, and casing damage at the Belridge diatomite field

Geologic, and historical well failure, production, and injection data were analyzed to guide development of three-dimensional geomechanical models of the Belridge diatomite field, California. The central premise of the numerical simulations is that spatial gradients in pore pressure induced by production and injection in a low permeability reservoir may perturb the local stresses and cause subsurface deformation sufficient to result in well failure. Time-dependent reservoir pressure fields that were calculated from three-dimensional black oil reservoir simulations were coupled uni-directionally to three-dimensional non-linear finite element geomechanical simulations. The reservoir models included nearly 100,000 gridblocks (100--200 wells), and covered nearly 20 years of production and injection. The geomechanical models were meshed from structure maps and contained more than 300,000 nodal points. Shear strain localization along weak bedding planes that causes casing dog-legs in the field was accommodated in the model by contact surfaces located immediately above the reservoir and at two locations in the overburden. The geomechanical simulations are validated by comparison of the predicted surface subsidence with field measurements, and by comparison of predicted deformation with observed casing damage. Additionally, simulations performed for two independently developed areas at South Belridge, Sections 33 and 29, corroborate their different well failure histories. The …
Date: May 1, 2000
Creator: Fredriche, Joanne T.; Deitrick, G. L.; Arguello, Jose G., Jr. & Derouffignac, E. P.
Object Type: Article
System: The UNT Digital Library
Richland Operations Office [DOE-RL] Implementation Plan for DOE Order 435.1 (open access)

Richland Operations Office [DOE-RL] Implementation Plan for DOE Order 435.1

This implementation plan identifies the status of each requirement for Hanford Site contractors, and provides the plan, cost, and time for achieving full implementation.
Date: May 1, 2000
Creator: Fritz, D. W.
Object Type: Report
System: The UNT Digital Library
Theoretical Minimum Energies to Produce Steel for Selected Conditions (open access)

Theoretical Minimum Energies to Produce Steel for Selected Conditions

The energy used to produce liquid steel in today's integrated and electric arc furnace (EAF) facilities is significantly higher than the theoretical minimum energy requirements. This study presents the absolute minimum energy required to produce steel from ore and mixtures of scrap and scrap alternatives. Additional cases in which the assumptions are changed to more closely approximate actual operating conditions are also analyzed. The results, summarized in Table E-1, should give insight into the theoretical and practical potentials for reducing steelmaking energy requirements. The energy values have also been converted to carbon dioxide (CO{sub 2}) emissions in order to indicate the potential for reduction in emissions of this greenhouse gas (Table E-2). The study showed that increasing scrap melting has the largest impact on energy consumption. However, scrap should be viewed as having ''invested'' energy since at one time it was produced by reducing ore. Increasing scrap melting in the BOF mayor may not decrease energy if the ''invested'' energy in scrap is considered.
Date: May 1, 2000
Creator: Fruehan, R. J.; Fortini, O.; Paxton, H. W. & Brindle, R.
Object Type: Report
System: The UNT Digital Library