States

Transition From in-Plane to Out-of-Plane Azimuthal Enhancement in Au+Au Collisions (open access)

Transition From in-Plane to Out-of-Plane Azimuthal Enhancement in Au+Au Collisions

The incident energy at which the azimuthal distributions in semi-central heavy ion collisions change from in-plane to out-of-plane enhancement--E{sub tran} is studied as a function of mass of emitted particles, their transverse momentum and centrality for Au+Au collisions. The analysis is performed in a reference frame rotated with the sidewards flow angle ({Theta}{sub flow}) relative to the beam axis. A systematic decrease of E{sub tran} as function of mass of the reaction products, their transverse momentum and collision centrality is evidenced. The predictions of a microscopic transport model (IQMD) are compared with the experimental results.
Date: August 9, 2000
Creator: Andronic, A.; Stoicea, G.; Petrovici, M.; Simion, V.; Crochet, P.; Alard, J. P. et al.
Object Type: Article
System: The UNT Digital Library
Atmospheric Radiation Measurement Program Facilities Newsletter, October 2000. (open access)

Atmospheric Radiation Measurement Program Facilities Newsletter, October 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: November 9, 2000
Creator: Atmospheric Radiation Measurement Program (U.S.)
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Calculation of Hamaker constants in non-aqueous fluid media (open access)

Calculation of Hamaker constants in non-aqueous fluid media

Calculations of the Hamaker constants representing the van der Waals interactions between conductor, resistor and dielectric materials are performed using Lifshitz theory. The calculation of the parameters for the Ninham-Parsegian relationship for several non-aqueous liquids has been derived based on literature dielectric data. Discussion of the role of van der Waals forces in the dispersion of particles is given for understanding paste formulation. Experimental measurements of viscosity are presented to show the role of dispersant truncation of attractive van der Waals forces.
Date: May 9, 2000
Creator: BELL,NELSON S. & DIMOS,DUANE B.
Object Type: Article
System: The UNT Digital Library
Canister Storage Building (CSB) Acceptance for Beneficial Use Index Roadmap of Supporting Documents (open access)

Canister Storage Building (CSB) Acceptance for Beneficial Use Index Roadmap of Supporting Documents

None
Date: May 9, 2000
Creator: BLACK, D.M.
Object Type: Report
System: The UNT Digital Library
Spent Nuclear Fuel (SNF) Project Final Safety Analysis Report (FSAR) (open access)

Spent Nuclear Fuel (SNF) Project Final Safety Analysis Report (FSAR)

None
Date: August 9, 2000
Creator: BREHM, J.R.
Object Type: Report
System: The UNT Digital Library
The Integrated Safety Management System Verification Enhancement Review of the Plutonium Finishing Plant (PFP) (open access)

The Integrated Safety Management System Verification Enhancement Review of the Plutonium Finishing Plant (PFP)

The primary purpose of the verification enhancement review was for the DOE Richland Operations Office (RL) to verify contractor readiness for the independent DOE Integrated Safety Management System Verification (ISMSV) on the Plutonium Finishing Plant (PFP). Secondary objectives included: (1) to reinforce the engagement of management and to gauge management commitment and accountability; (2) to evaluate the ''value added'' benefit of direct public involvement; (3) to evaluate the ''value added'' benefit of direct worker involvement; (4) to evaluate the ''value added'' benefit of the panel-to-panel review approach; and, (5) to evaluate the utility of the review's methodology/adaptability to periodic assessments of ISM status. The review was conducted on December 6-8, 1999, and involved the conduct of two-hour interviews with five separate panels of individuals with various management and operations responsibilities related to PFP. A semi-structured interview process was employed by a team of five ''reviewers'' who directed open-ended questions to the panels which focused on: (1) evidence of management commitment, accountability, and involvement; and, (2) consideration and demonstration of stakeholder (including worker) information and involvement opportunities. The purpose of a panel-to-panel dialogue approach was to better spotlight: (1) areas of mutual reinforcement and alignment that could serve as good examples …
Date: February 9, 2000
Creator: BRIGGS, C.R.
Object Type: Report
System: The UNT Digital Library
Microfabrication and Micropatterning with Soft Lithography (open access)

Microfabrication and Micropatterning with Soft Lithography

None
Date: August 9, 2000
Creator: Baca, Justin T. & Myers, Ramona L.
Object Type: Article
System: The UNT Digital Library
The solvated electron in supercritical water (open access)

The solvated electron in supercritical water

In order to investigate the feasibility for high-efficiency supercritical-water-cooled nuclear reactors, a study of radiation chemistry in supercritical water has been undertaken. Preliminary results in measurement of the optical absorption of the hydrated electron are reported, and compared with recent anion cluster data.
Date: March 9, 2000
Creator: Bartels, D. M.; Takahashi, K.; Cline, J. & Jonah, C. D.
Object Type: Article
System: The UNT Digital Library
Comparison of imaging spectrometers (open access)

Comparison of imaging spectrometers

Realistic signal to noise performance estimates for the various types of instruments being considered for NGST are compared, based on the point source detection values quoted in the available ISIM final reports. The corresponding sensitivity of the various types of spectrometers operating in a full field imaging mode, for both emission line objects and broad spectral distribution objects, is computed and displayed. For the purpose of seeing the earliest galaxies, or the faintest possible emission line sources, the imaging Fourier transform spectrometer emerges superior to all others, by orders of magnitude in speed.
Date: January 9, 2000
Creator: Bennett, C
Object Type: Article
System: The UNT Digital Library
Detection and Assessment Using Positron Emission Tomography of Genetically Determined Defects in Myocardial Fatty Acid Utilization. Final report, 8/1/93-6/30/97 (open access)

Detection and Assessment Using Positron Emission Tomography of Genetically Determined Defects in Myocardial Fatty Acid Utilization. Final report, 8/1/93-6/30/97

An approach using positron emission tomography (PET) was developed, validated and used to measure myocardial fatty acid metabolism in patients with inherited forms of heart failure. Abnormalities were correlated with the severity of the clinical illness. The approach developed was also shown to identify abnormalities in myocardial fatty acid metabolism in some patients with acquired forms of heart failure. The PET technique thus permits identification of abnormal fatty acid metabolism and provides an approach to evaluate the efficacy of interventional strategies.
Date: April 9, 2000
Creator: Bergmann, Steven R.
Object Type: Report
System: The UNT Digital Library
Nonperturbative geometrodynamic calculation of chaotic mixing time in charged-particle beams (open access)

Nonperturbative geometrodynamic calculation of chaotic mixing time in charged-particle beams

The time scale for irreversible mixing in a charged-particle bunch as a consequence of time-independent, nonlinear space-charge forces is estimated analytically to be a few plasma periods, much shorter than the two-body relaxation time. The basis for the estimate is a metric tensor inferred from Hamilton's least-action principle. Geodesics derived from the metric tensor correspond to particle trajectories. Their behavior reflects the properties of the curvilinear manifold in which they are embedded, among which irregularities associated with parametric resonances are of foremost importance. Exponential separation of nearby chaotic trajectories is thereby accessible to the geometrodynamic approach. The e-folding time associated with dispersing an initially localized perturbation throughout the bunch characterizes the process of irreversible mixing. It thereby constrains both the placement and size of hardware for emittance compensation that may be needed, for example, to undo phase-space degradation arising from coherent synchrotron radiation in magnetic bends. These constraints are estimated for linacs powering modern infrared and x-ray free-electron lasers.
Date: February 9, 2000
Creator: Bohn, C.L.
Object Type: Article
System: The UNT Digital Library
Process Development for CIGS Based Thin Film Photovoltaics Modules, Phase II Technical Report (open access)

Process Development for CIGS Based Thin Film Photovoltaics Modules, Phase II Technical Report

As a technology partner with NREL, Global Solar Energy (GSE) has initiated an extensive and systematic plan to accelerate the commercialization of thin-film photovoltaics (PV) based on copper indium gallium diselenide (CIGS). The distinguishing feature of the GSE manufacturing process is the exclusive use of lightweight, flexible substrates. GSE has developed the technology to fabricate CIGS photovoltaics on both stainless-steel and polymer substrates. CIGS deposited on flexible substrates can be fabricated into either flexible or rigid modules. Low-cost, rigid PV panels for remote power, bulk/utility, telecommunication, and rooftop applications have been produced by affixing the flexible substrate to an inexpensive rigid panel by lamination or adhesive. Stainless-steel-based PV modules are fabricated by a novel interconnect method that avoids the use of wires or foils and soldered connections. In the case of polymer-based PV modules, the continuous roll is not sectioned into individual panels until the module buss and power leads are attached. Roll-to-roll vacuum deposition has several advantages that translate directly to reduced capital costs, greater productivity, improved yield, greater reliability, lower maintenance, and a larger volume of PV material. In combination with roll-to-roll processing, GSE has developed evaporation deposition operations that enable low-cost and high-efficiency CIGS modules. The CIGS …
Date: November 9, 2000
Creator: Britt, J.; Wiedeman, S. & Albright, S.
Object Type: Report
System: The UNT Digital Library
Characterization, Washing, Leaching, and Filtration of C-104 Sludge (open access)

Characterization, Washing, Leaching, and Filtration of C-104 Sludge

Approximately 1,400 g of wet Hanford Tank C-104 Sludge was evaluated by Battelle for the high-level waste (HLW) pretreatment processes of ultrafiltration, dilute caustic washing, and elevated-temperature caustic leaching. The filterability of diluted C-104 sludge was measured with a 0.1-{micro}m sintered metal Mott filter using a 24-inch-long, single-element, crossflow filtration system (cells unit filter [CUF]). While the filtrate was being recirculated prior to washing and leaching, a 6.9 wt% solids slurry was evaluated with a matrix of seven 1-hour conditions of varying trans-membrane pressure (30 to 70 psid) and axial velocity (9 to 15 ft/s). The filtrate flux and backpulse efficiency were determined for each condition. The slurry was concentrated to 23 wt% solids, a second matrix of six 1-hour conditions was performed, and data analogous to that recorded in the first matrix were obtained. The low-solids-concentration matrix produced filtrate flux rates that ranged from 0.038 to 0.083 gpm/ft{sup 2}. The high-solids-concentration matrix produced filtrate flux rates that ranged from 0.0095 to 0.0172 gpm/ft{sup 2}. In both cases, the optimum filtrate flux was at the highest axial velocity (15 ft/s) and transmembrane pressure had little effect. Nearly all of the measured filtrate fluxes were more than an order of magnitude …
Date: June 9, 2000
Creator: Brooks, K. P.; Bredt, P. R.; Golcar, G. R.; Hartley, S. A.; Jagoda, L. K.; Rappe, K. G. et al.
Object Type: Report
System: The UNT Digital Library
ISOcxx: The C++ portability package (open access)

ISOcxx: The C++ portability package

The level of C++ compliers' adherence to the ISO C++ standard varies considerably from compiler to compiler. This variability has significantly hindered users' attempts as standard-compliant C++ coding practices. ISOcxx is a software package that addresses such deficient aspects of users' C++ development environments. This portability package: (1) probes an environment to identify areas of non-compliance (defects) with the standard, and (2) supplies, where possible, compliance code so as to mitigate (cure) the ill effects of the detected defects. Each defect typically results from a feature that is required by the ISO C++ standard, but that a particular environment omits entirely, provides only incompletely, matches to an outdated draft of the standard, or otherwise incorrectly supports. A cure is applicable if test programs demonstrating the corresponding defect can be successfully compiled and run when the compliance code is incorporated. Where no compliance code is available, client code is nonetheless made aware of the defect and can thus avoid the offending construct. Thus, this package allows client code to be maximally compliant with the international C++ standard, yet still be acceptable to many otherwise-defective environments.
Date: February 9, 2000
Creator: Brown, W.E.
Object Type: Article
System: The UNT Digital Library
Time and Temperature Test Results for PFP Thermal Stabilization Furnaces (open access)

Time and Temperature Test Results for PFP Thermal Stabilization Furnaces

The national standard for plutonium storage acceptability (standard DOE-STD-3013-99, generally known as ''the 3013 standard'') has been revised to clarify the requirement for processes that will produce acceptable storage materials. The 3013 standard (Reference 1) now states that ''Oxides shall be stabilized by heating the material in an oxidizing atmosphere to a Material Temperature of at least 950 C (1742 F) for not less than 2 hours.'' The process currently in use for producing stable oxides for storage at the Plutonium Finishing Plant (PFP) heats a furnace atmosphere to 1000 C and holds it there for 2 hours. The temperature of the material being stabilized is not measured directly during this process. The Plutonium Process Support Laboratories (PPSL) were requested to demonstrate that the process currently in use at PFP is an acceptable method of producing stable plutonium dioxide consistently. A spare furnace identical to the production furnaces was set up and tested under varying conditions with non-radioactive surrogate materials. Reference 2 was issued to guide the testing program. The process currently in use at the PFP for stabilizing plutonium-bearing powders was shown to heat all the material in the furnace to at least 950 C for at least 2 …
Date: August 9, 2000
Creator: COMPTON, J.A.
Object Type: Report
System: The UNT Digital Library
CARBON DIOXIDE AS A FEEDSTOCK. (open access)

CARBON DIOXIDE AS A FEEDSTOCK.

This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us. Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the scope of this report, except where it overlaps utilization, for example in converting CO{sub 2} to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops. The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO{sub 2} as a starting …
Date: December 9, 2000
Creator: CREUTZ,C. & FUJITA,E.
Object Type: Article
System: The UNT Digital Library
CARBON DIOXIDE AS A FEEDSTOCK. (open access)

CARBON DIOXIDE AS A FEEDSTOCK.

This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us. Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the scope of this report, except where it overlaps utilization, for example in converting CO{sub 2} to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops. The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO{sub 2} as a starting …
Date: December 9, 2000
Creator: CREUTZ,C. & FUJITA,E.
Object Type: Article
System: The UNT Digital Library
Development of a coupled dynamics code with transport theory capability and application to accelerator driven systems transients (open access)

Development of a coupled dynamics code with transport theory capability and application to accelerator driven systems transients

The VARIANT-K and DIF3D-K nodal spatial kinetics computer codes have been coupled to the SAS4A and SASSYS-1 liquid metal reactor accident and systems analysis codes. SAS4A and SASSYS-1 have been extended with the addition of heavy liquid metal (Pb and Pb-Bi) thermophysical properties, heat transfer correlations, and fluid dynamics correlations. The coupling methodology and heavy liquid metal modeling additions are described. The new computer code suite has been applied to analysis of neutron source and thermal-hydraulics transients in a model of an accelerator-driven minor actinide burner design proposed in an OECD/NEA/NSC benchmark specification. Modeling assumptions and input data generation procedures are described. Results of transient analyses are reported, with emphasis on comparison of P1 and P3 variational nodal transport theory results with nodal diffusion theory results, and on significance of spatial kinetics effects.
Date: March 9, 2000
Creator: Cahalan, J. E.; Ama, T.; Palmiotti, G.; Taiwo, T. A. & Yang, W. S.
Object Type: Article
System: The UNT Digital Library
Gas Phase Chemical Detection with an Integrated Chemical Analysis System (open access)

Gas Phase Chemical Detection with an Integrated Chemical Analysis System

None
Date: October 9, 2000
Creator: Casalnuovo, S. A.; Frye-Mason, G. C.; Kottenstette, R.; Heller, E. J.; Matzke, C. M.; Lewis, P. R. et al.
Object Type: Article
System: The UNT Digital Library
Device characteristics of the PnP AlGaAs/InGaAsN/GaAs double heterojunction bipolar transistor (open access)

Device characteristics of the PnP AlGaAs/InGaAsN/GaAs double heterojunction bipolar transistor

The authors have demonstrated a functional PnP double heterojunction bipolar transistor (DHBT) using AlGaAs, InGaAsN, and GaAs. The band alignment between InGaAsN and GaAs has a large {triangle}E{sub C} and a negligible {triangle}E{sub V}, and this unique characteristic is very suitable for PnP DHBT applications. The metalorganic vapor phase epitaxy (MOCVD) grown Al{sub 0.3}Ga{sub 0.7}As/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}/GaAs PnP DHBT is lattice matched to GaAs and has a peak current gain of 25. Because of the smaller bandgap (Eg = 1.20 eV) of In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} used for the base layer, this device has a low V{sub ON} of 0.79 V, which is 0.25 V lower than in a comparable Pnp AlGaAs/GaAs HBT. And because GaAs is used for the collector, its BV{sub CEO} is 12 V, consistent with BV{sub CEO} of AlGaAs/GaAs HBTs of comparable collector thickness and doping level.
Date: February 9, 2000
Creator: Chang, Ping-Chih; Li, N. Y.; Laroche, J. R.; Baca, Albert G.; Hou, H. Q. & Ren, F.
Object Type: Article
System: The UNT Digital Library
The effect of the number of wavebands used in spectral radiation heat transfer calculations (open access)

The effect of the number of wavebands used in spectral radiation heat transfer calculations

A spectral radiation heat transfer model that conserves emitted and absorbed energy has been developed and used to model the combustion space of an industrial glass furnace. This comprehensive radiation heat transfer model coupled with a computational fluid dynamics (CFD) code was used to investigate the effect of spectral dependencies on the computed results. The results of this work clearly indicate the need for a spectral approach as opposed to a gray body approach since the gray body approach (one waveband) severely underestimates the energy emitted via radiation.
Date: May 9, 2000
Creator: Chang, S. L.; Golchert, B. & Petrick, M.
Object Type: Article
System: The UNT Digital Library
A numerical investigation of gasoline production from multi-stage FCC systems (open access)

A numerical investigation of gasoline production from multi-stage FCC systems

Staged, fluid catalytic cracking (FCC) processes are deemed to have the potential to enhance FCC performance in the areas of product selectivity, operating flexibility, throughput, reliability, operating costs, and emissions. Computational fluid dynamic (CFD) codes are used to analyze various staged FCC concepts to help accelerate their development into commercial products. Three conceptual multi-stage FCC systems were evaluated using a validated CFD code. The results indicated potential increases of gasoline production from these conceptual designs.
Date: May 9, 2000
Creator: Chang, S. L.; Zhou, C. Q. & Petrick, M.
Object Type: Article
System: The UNT Digital Library
A validation process for multi-phase reacting flow CFD code (open access)

A validation process for multi-phase reacting flow CFD code

Computational fluid dynamic (CFD) code calculates flow properties for the analysis of a flow system. Flow properties are computed based on conservation principles and various phenomenological models. The accuracy of the computed flow properties highly depends on the validity of the models and the degree of numerical convergence. Validation of a CFD code is essential for application of an engineering system. Multiphase reacting flows are common in industrial applications and few CFD code are available. A CFD code was developed for the simulation of multiphase reacting flows. A validation process was also developed for such a CFD code. The validation was performed for several cases. Examples of industrial devices which are multiphase reacting flow systems include catalytic cracking reactors, glass melting furnaces, coal-fired combustors, and diesel engines.
Date: May 9, 2000
Creator: Chang, S. L.; Zhou, C. Q. & Petrick, M.
Object Type: Article
System: The UNT Digital Library
Appropriations for FY2001: U.S. Department of Agriculture and Related Agencies (open access)

Appropriations for FY2001: U.S. Department of Agriculture and Related Agencies

Appropriations are one part of a complex federal budget process that includes budget resolutions, appropriations (regular, supplemental, and continuing) bills, rescissions, and budget reconciliation bills. This report is a guide to one of the 13 regular appropriations bills that Congress passes each year. It is designed to supplement the information provided by the House and Senate Appropriations Subcommittees on Agriculture Appropriations.
Date: November 9, 2000
Creator: Chite, Ralph M.
Object Type: Report
System: The UNT Digital Library