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Magnetized Target Fusion (MTF): A Low-Cost Fusion Development Path (open access)

Magnetized Target Fusion (MTF): A Low-Cost Fusion Development Path

Simple transport-based scaling laws are derived to show that a density and time regime intermediate between conventional magnetic confinement and conventional inertial confinement offers attractive reductions in system size and energy when compared to magnetic confinement and attractive reductions in heating power and intensity when compared to inertial confinement. This intermediate parameter space appears to be readily accessible by existing and near term pulsed power technologies. Hence, the technology of the Megagauss conference opens up an attractive path to controlled thermonuclear fusion.
Date: October 19, 1998
Creator: Lindemuth, I.R.; Siemon, R.E.; Kirkpatrick, R.C. & Reinovsky, R.E.
Object Type: Article
System: The UNT Digital Library
Application of 2-D Simulations to Z-Pinch Experiment Design and Analysis (open access)

Application of 2-D Simulations to Z-Pinch Experiment Design and Analysis

The successful 2-D simulations of z-pinch experiments (reproducing such features as the measured experimental current drive, radiation pulse shape, peak power and total radiated energy) can lead to a better understanding of the underlying physics in z-pinch implosions and to the opportunity to use such simulations in the analysis of experimental data and in the design of new experiments. Such use has been made with LANL simulations of experiments on the Sandia Saturn and Z accelerators. Applications have included ''vacuum'' and ''dynamic'' hohlraum experiments; variations in mass, radius and length; and ''nested'' array configurations. Notable examples include the explanation of the power/length results in reduced length pinches and the prediction of the current best power and pulsewidth nested array experiment. Examples of circumstances where the simulation results do not match the experiments will be given along with a discussion of opportunities for improved simulation results.
Date: October 19, 1998
Creator: Peterson, D. L.; Bowers, R. L.; Matuska, W.; Chandler, G. A.; Deeney, C.; Derzon, M. S. et al.
Object Type: Article
System: The UNT Digital Library
RULLI/a Photon Counting Imager (open access)

RULLI/a Photon Counting Imager

The Remote Low Light Imaging (RULLI) system responds to individual photons using a modification to conventional image intensifier technology and fast timing electronics. Each photon received at the detector is resolved in three dimensions (X, Y, and time). The accumulation of photons over time allows the system to image with very low light levels, such as starlight illumination. Using a low power pulsed laser and very fine time discrimination, three dimensional imaging has been accomplished with a vertical resolution of five cm.
Date: October 19, 1998
Creator: Albright, K. L.; Smith, R. C.; Ho, C.; Wilson, S. K.; Bradley, J.; Bird, A. et al.
Object Type: Article
System: The UNT Digital Library
FUNDAMENTAL STUDY OF LOW-NOx COMBUSTION FLY ASH UTILIZATION (open access)

FUNDAMENTAL STUDY OF LOW-NOx COMBUSTION FLY ASH UTILIZATION

This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over fifty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the …
Date: October 19, 1998
Creator: SUUBERG, ERIC M. & HURT, ROBERT H.
Object Type: Report
System: The UNT Digital Library
Domain decomposition methods for parallel laser-tissue models with Monte Carlo transport (open access)

Domain decomposition methods for parallel laser-tissue models with Monte Carlo transport

Achieving parallelism in simulations that use Monte Carlo transport methods presents interesting challenges. For problems that require domain decomposition, load balance can be harder to achieve. The Monte Carlo transport package may have to operate with other packages that have different optimal domain decompositions for a given problem. To examine some of these issues, we have developed a code that simulates the interaction of a laser with biological tissue; it uses a Monte Carlo method to simulate the laser and a finite element model to simulate the conduction of the temperature field in the tissue. We will present speedup and load balance results obtained for a suite of problems decomposed using a few domain decomposition algorithms we have developed.
Date: October 19, 1998
Creator: Alme, H.J.; Rodrique, G. & Zimmerman, G.
Object Type: Article
System: The UNT Digital Library
Fluorinated Dodecaphenylporphyrins: Synthetic and Electrochemical Studies Including the First Evidence of Intramolecular Electron Transfer Between an Fe(II) Porphyrin -Anion Radical and an Fe(I) Porphyrin (open access)

Fluorinated Dodecaphenylporphyrins: Synthetic and Electrochemical Studies Including the First Evidence of Intramolecular Electron Transfer Between an Fe(II) Porphyrin -Anion Radical and an Fe(I) Porphyrin

Dodecaphenylporphyrins with varying degrees of fluorination of the peripheral phenyl rings (FXDPPS) were synthesized as model compounds for studying electronic effects in nonplan~ porphyrins, and detailed electrochemical studies of the chloroiron(HI) complexes of these compounds were undertaken. The series of porphyrins, represented as FeDPPCl and as FeFXDPPCl where x = 4, 8 (two isomers), 12, 20,28 or 36, could be reversibly oxidized by two electrons in dichloromethane to give n-cation radicals and n-dications. All of the compounds investigated could also be reduced by three electrons in benzonitrile or pyridine. In benzonitrile, three reversible reductions were observed for the unfluorinated compound FeDPPC1, whereas the FeFXDPPCl complexes generally exhibited irreversible first and second reductions which were coupled to chemical reactions. The chemical reaction associated with the first reduction involved a loss of the chloride ion after generation of Fe FXDPPC1. The second chemical reaction involved a novel intramolecular electron transfer between the initially generated Fe(H) porphyrin n-anion radical and the final Fe(I) porphyrin reduction product. In pyridine, three reversible one electron reductions were observed with the second reduction affording stable Fe(II) porphyrin o - anion radicals for ail of the complexes investigated.
Date: October 19, 1998
Creator: D'Souza, Francis; Forsyth, Timothy P.; Fukuzumi, Shunichi; Kadish, Karl M.; Krattinger, Benedicte; Lin, Min et al.
Object Type: Article
System: The UNT Digital Library
A neutronic feasibility study for LEU conversion of the WWR-SM research reactor in Uzbekistan. (open access)

A neutronic feasibility study for LEU conversion of the WWR-SM research reactor in Uzbekistan.

The WWR-SM research reactor in Uzbekistan has operated at 10 MW since 1979, using Russian-supplied IRT-3M fuel assemblies containing 90% enriched uranium. Burnup tests of three full-sized IRT-3M FA with 36% enrichment were successfully completed to a burn up of about {approximately}50% in 1987-1989. In August 1998, four IRT-3M FA with 36% enriched uranium were loaded into the core to initiate conversion of the entire core to 36% enriched fuel. This paper presents the results of equilibrium fuel cycle comparisons of the reactor using HEU (90%) and HEU (36%) IRT-3M fuel and compares results with the performance of IRT-4M FA containing LEU (19.75%). The results show that an LEU (19.75%) density of 3.8 g/cm{sup 3} is required to match the cycle length of the HEU (90%) core and an LEU density 3.9 g/cm{sup 3} is needed to match the cycle length of the HEU (36%) core.
Date: October 19, 1998
Creator: Rakhmanov, A.
Object Type: Article
System: The UNT Digital Library
Summary of Tritium Tracking and Groundwater Monitoring at the Hanford Site 200 Area SALDS - FY 1998 (open access)

Summary of Tritium Tracking and Groundwater Monitoring at the Hanford Site 200 Area SALDS - FY 1998

Treated water from the 200 Area Effluent Treatment Facility (ETF) is discharged to a disposal site in accordance with the State Waste Discharge Permit ST-4500. This disposal site is referred to as the State-Approved Land Disposal Site (SALDS). In accordance with the discharge permit, the groundwater at the SALDS is routinely sampled. The results of the groundwater sampling are reported in quarterly discharge monitoring reports. In 1997, the USDOE also committed to the issuance of an annual summary report of groundwater monitoring results and evaluation with updates to the groundwater monitoring plan as appropriate. This report summarizes the groundwater information for FY 1998.
Date: October 19, 1998
Creator: DB Barnett, MP Bergeron, CR Cole, MD Freshley, SK Wurstner
Object Type: Report
System: The UNT Digital Library
Self-Organized Growth of Alloy Superlattices (open access)

Self-Organized Growth of Alloy Superlattices

We predict theoretically and demonstrate experimentally the spontaneous formation of a superlattice during crystal growth. When a strained alloy grows by "step flow", the steps at the surface form periodic bunches. The resulting modulated strain biases the incorporation of the respective alloy components at different steps in the bunch, leading to the formation of a superlattice. X-ray diffraction and electron microscopy for SiGe grown on Si give clear evidence for such spontaneous superlattice formation.
Date: October 19, 1998
Creator: Chason, E.; Floro, J. A.; Follstaedt, D. M.; Lagally, M. G.; Liu, F.; Tersoff, J. et al.
Object Type: Article
System: The UNT Digital Library
Hydrogen-fueled polymer electrolyte fuel cell systems for transportation. (open access)

Hydrogen-fueled polymer electrolyte fuel cell systems for transportation.

The performance of a polymer electrolyte fuel cell (PEFC) system that is fueled directly by hydrogen has been evaluated for transportation vehicles. The performance was simulated using a systems analysis code and a vehicle analysis code. The results indicate that, at the design point for a 50-kW PEFC system, the system efficiency is above 50%. The efficiency improves at partial load and approaches 60% at 40% load, as the fuel cell operating point moves to lower current densities on the voltage-current characteristic curve. At much lower loads, the system efficiency drops because of the deterioration in the performance of the compressor, expander, and, eventually, the fuel cell. The results also indicate that the PEFC system can start rapidly from ambient temperatures. Depending on the specific weight of the fuel cell (1.6 kg/kW in this case), the system takes up to 180s to reach its design operating conditions. The PEFC system has been evaluated for three mid-size vehicles: the 1995 Chrysler Sedan, the near-term Ford AIV (Aluminum Intensive Vehicle) Sable, and the future P2000 vehicle. The results show that the PEFC system can meet the demands of the Federal Urban Driving Schedule and the Highway driving cycles, for both warm and …
Date: October 19, 1998
Creator: Ahluwalia, R.; Doss, E.D. & Kumar, R.
Object Type: Report
System: The UNT Digital Library
Unipolar Complementary Circuits Using Double Electron Layer Tunneling Tansistors (open access)

Unipolar Complementary Circuits Using Double Electron Layer Tunneling Tansistors

We demonstrate unipolar complementary circuits consisting of a pair of resonant tunneling transistors based on the gate control of 2D-2D interlayer tunneling, where a single transistor - in addition to exhibiting a welldefined negative-differential-resistance can be operated with either positive or negative transconductance. Details of the device operation are analyzed in terms of the quantum capacitance effect and band-bending in a double quantum well structure, and show good agreement with experiment. Application of resonant tunneling complementary logic is discussed by demonstrating complementary static random access memory using two devices connected in series.
Date: October 19, 1998
Creator: Blount, M. A.; Hafich, M. J.; Moon, J. S.; Reno, J. L. & Simmons, J. A.
Object Type: Article
System: The UNT Digital Library
A Monte Carlo burnup code linking MCNP and REBUS. (open access)

A Monte Carlo burnup code linking MCNP and REBUS.

The REBUS-3 burnup code, used in the ANL RERTR Program, is a very general code that uses diffusion theory (DIF3D) to obtain the fluxes required for reactor burnup analyses. Diffusion theory works well for most reactors. However, to include the effects of exact geometry and strong absorbers that are difficult to model using diffusion theory, a Monte Carlo method is required. MCNP, a general-purpose, generalized-geometry, time-dependent, Monte Carlo transport code, is the most widely used Monte Carlo code. This paper presents a linking of the MCNP code and the REBUS burnup code to perform these difficult burnup analyses. The linked code will permit the use of the full capabilities of REBUS which include non-equilibrium and equilibrium burnup analyses. Results of burnup analyses using this new linked code are also presented.
Date: October 19, 1998
Creator: Hanan, N. A.
Object Type: Article
System: The UNT Digital Library
Economics and the evaluation of publicly funded energy R and D (open access)

Economics and the evaluation of publicly funded energy R and D

There are three major areas in which economics can contribute to the evaluation of federal R and D: assessment of net benefits, ex ante expected as well as ex post realized; tailoring of R and D portfolios to policy goals; and guiding the contractual organization of R and D production. Additionally, evaluation of R and D and scientific activity tend to be distinctly retrospective, principally because of the long lags between the initial production activity and the observability of consequences. Extending the purview of economic evaluation of R and D, they find ample opportunity for evaluation that can inform current R and D management practice. The conduct of R and D is organized through a series of explicit and implicit contracts designed to elicit long-term commitments by some agents while attempting to limit the commitment by others. It is natural to consider the efficiency with which R and D is conducted as a subject for economic inquiry, although in practice such inquiries generally are restricted to accounting exercises. In evaluating the efficiency with which R and D is done, the current ordinary practice is to look at labor rates and equipment and materials prices while considering quantities of those items …
Date: October 19, 1998
Creator: Jones, D.W. & Paik, I.K.
Object Type: Article
System: The UNT Digital Library
Probabilistic seismic hazard characterization and design parameters for the Pantex Plant (open access)

Probabilistic seismic hazard characterization and design parameters for the Pantex Plant

The Hazards Mitigation Center at Lawrence Livermore National Laboratory (LLNL) updated the seismic hazard and design parameters at the Pantex Plant. The probabilistic seismic hazard (PSH) estimates were first updated using the latest available data and knowledge from LLNL (1993, 1998), Frankel et al. (1996), and other relevant recent studies from several consulting companies. Special attention was given to account for the local seismicity and for the system of potentially active faults associated with the Amarillo-Wichita uplift. Aleatory (random) uncertainty was estimated from the available data and the epistemic (knowledge) uncertainty was taken from results of similar studies. Special attention was given to soil amplification factors for the site. Horizontal Peak Ground Acceleration (PGA) and 5% damped uniform hazard spectra were calculated for six return periods (100 yr., 500 yr., 1000 yr., 2000 yr., 10,000 yr., and 100,000 yr.). The design parameters were calculated following DOE standards (DOE-STD-1022 to 1024). Response spectra for design or evaluation of Performance Category 1 through 4 structures, systems, and components are presented.
Date: October 19, 1998
Creator: Bernreuter, D. L.; Foxall, W. & Savy, J. B.
Object Type: Report
System: The UNT Digital Library
Westerner World (Lubbock, Tex.), Ed. 1 Monday, October 19, 1998 (open access)

Westerner World (Lubbock, Tex.), Ed. 1 Monday, October 19, 1998

Student newspaper from Lubbock High School in Lubbock, Texas that includes local and school news along with advertising.
Date: October 19, 1998
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 47, Ed. 1 Monday, October 19, 1998 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 47, Ed. 1 Monday, October 19, 1998

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: October 19, 1998
Creator: Allam, Heather
Object Type: Newspaper
System: The Gateway to Oklahoma History
DART transportation and maintenance employees feed the homeless Saturday, October 24 (open access)

DART transportation and maintenance employees feed the homeless Saturday, October 24

News release about a charitable "Feed the Homeless" lunch sponsored by DART employees.
Date: October 19, 1998
Creator: Lyons, Morgan
Object Type: Text
System: The Portal to Texas History
Perry Daily Journal (Perry, Okla.), Vol. 105, No. 204, Ed. 1 Monday, October 19, 1998 (open access)

Perry Daily Journal (Perry, Okla.), Vol. 105, No. 204, Ed. 1 Monday, October 19, 1998

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: October 19, 1998
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History