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QCD sum rule calculation of {gamma}{gamma}{sup *} {r_arrow} {pi}{sup 0} transition form factor

Description: The authors develop a QCD sum rule analysis of the form factor F{sub {gamma}{sup *}{gamma}{sup *}{pi}{sup 0}}(q{sup 2},Q{sup 2}) in the region where virtuality of one of the spacelike photons is small q{sup 2} {much_lt} 1 GeV{sup 2} while another is large: Q{sup 2} {approx_gt} 1 GeV{sup 2}. They construct the operator product expansion suitable for this kinematic situation and obtain a QCD sum rule for F{sub {gamma}{sup *}{gamma}{sup *}{pi}{sup 0}}(0, Q{sup 2}). Their results confirm expectatio… more
Date: November 1, 1995
Creator: A.V.Radyushkin & R.T.Ruskov
Partner: UNT Libraries Government Documents Department
open access

Rapidity dependence of the inclusive J/{Psi} production in p{bar p} collisions at {radical}s = 1.8 TeV

Description: We have studied J/{psi} production in p{bar p} collisions at {radical}s = 1.8 TeV with the D0 detector at Fermilab, using a {mu}{sup +}{mu}{sup {minus}} data sample collected during the 1994--1995 collider run. We have measured the inclusive J/{psi} production cross section as a function of the J/{psi} transverse momentum, p{sub T}{sup J/{psi}}, in the central and forward rapidity regions. The cross section d{sigma}/dp{sub T}{sup J/{psi}} for {vert_bar}{eta}{sup J/{psi}}{vert_bar}<0.6 covers th… more
Date: November 1, 1995
Creator: Abachi, S.
Partner: UNT Libraries Government Documents Department
open access

Developing a Panelboard Trainer Using SIMVOX and PROVOX

Description: Several challenges existed in creating a system that would be valuable for training operators: the robustness and accuracy of the process model, the operator interface to the process, and the communication between the operator interface and the process models. Cost and implementation time were also important factors. Two possible implementation plans were examined. The first option was to develop a computer tool through which the operator could operate the process through interaction with the m… more
Date: November 20, 1995
Creator: Abbott, L. A.
Partner: UNT Libraries Government Documents Department
open access

The endcap Cherenkov ring imaging detector at SLD

Description: The authors present the Cherenkov Ring Imaging Detector in the endcap regions of the SLD detector and report initial performance. The endcap CRID was completed and commissioned in 1993 and is fully operational for the 1994 run. First Cherenkov rings have been observed. The endcap CRID detectors and fluid systems are described and initial operational experience is discussed.
Date: 1995-11~
Creator: Abe, K.; Hasegawa, K.; Hawegawa, Y.; Iwasaki, Y.; Suekane, F.; Yuta, H. et al.
Partner: UNT Libraries Government Documents Department
open access

Transition and gap models of forest dynamics

Description: Article discussing transition and gap models of forest dynamics.
Date: November 1, 1995
Creator: Acevedo, Miguel F.; Urban, D. L. & Ablan, Magdiel
Partner: UNT College of Arts and Sciences
open access

Electron irradiation-induced mechanical property changes in reactor pressure vessel alloys

Description: High-energy electrons were used to study tensile property changes in simple Fe-Cu and Fe-Cu-Mn alloys irradiated at 288C. A comparison was made with neutron irradiation data on the same alloys. An apparent effect of alloy chemistry was observed in which the presence of Mn affected embrittlement differently for electron and neutron irradiation. Comparison of previous experimental studies with the present experimental results indicates that electrons may be more efficient than fast neutrons at pr… more
Date: November 1, 1995
Creator: Alexander, D. E.; Rehn, L. E.; Odette, G. R. & Lucas, G. E.
Partner: UNT Libraries Government Documents Department
open access

Dynamical model for DNA sequences

Description: This article discusses a dynamical model for DNA sequences based on the assumption that the statistical properties of DNA paths are determined by the joint action of two processes, one deterministic with long-range correlations and the other random and δ-function correlated.
Date: November 1995
Creator: Allegrini, Paolo; Barbi, M.; Grigolini, Paolo & West, Bruce J.
Partner: UNT College of Arts and Sciences
open access

New instrumentation in Argonne`s HVEM-Tamdem Facility: Expanded capability for in situ ion beam studies

Description: During 1995, a state-of-the-art intermediate voltage electron microscope (IVEM) has been installed in the HVEM-Tandem Facility with in situ ion irradiation capabilities similar to those of the HVEM. A 300 kV Hitachi H-9000NAR has been interfaced to the two ion accelerators of the Facility, with a spatial resolution for imaging which is nearly an order of magnitude better than that for the 1.2 MV HVEM which dates from the early 1970s. The HVEM remains heavily utilized for electron- and ion irrad… more
Date: November 1, 1995
Creator: Allen, Charles W.; Funk, Loren L. & Ryan, Edward A.
Partner: UNT Libraries Government Documents Department
open access

High temperature vitrification of surrogate Savannah River Site (SRS) mixed waste materials

Description: The Savannah River Technology Center (SRTC) has been funded through the DOE Office of Technology Development (DOE-OTD) to investigate high-temperature vitrification technologies for the treatment of diverse low-level and mixed wastes. High temperature vitrification is a likely candidate for processing heterogeneous solid wastes containing low levels of activity. Many SRS wastes fit into this category. Plasma torch technology is one high temperature vitrification method. A trial demonstration of… more
Date: November 1, 1995
Creator: Applewhite-Ramsey, A.; Schumacher, R. F.; Spatz, T. L.; Newsom, R. A.; Circeo, L. J. & Danjaji, M. B.
Partner: UNT Libraries Government Documents Department
open access

US Light-Water Reactor spent fuel inventory-fissile distribution

Description: Those conducting waste management studies to reduce the potential for a nuclear criticality accident in a future geological repository must examine the quantities and distribution of fissile isotopes that are present in discharged boiling-water reactor (BWR) and pressurized-water reactor (PWR) spent nuclear fuel (SNF) scheduled for disposition. The major fissile isotopes present in LWR fuels that impact criticality safety are the nuclides, {sup 235}U, {sup 239}Pu, and {sup 24l}Pu. The sum of th… more
Date: November 8, 1995
Creator: Ashline, R.C. & Forsberg, C.W.
Partner: UNT Libraries Government Documents Department
open access

Studies of defects in the near-surface region and at interfaces using low energy positron beams

Description: Positron Annihilation Spectroscopy (PAS) is a powerful probe to study open-volume defects in solids. Its success is due to the propensity of positrons to seek out low-density regions of a solid, such as vacancies and voids, and the emissions of gamma rays from their annihilations that carry information about the local electronic environment. The development of low-energy positron beams allows probing of defects to depths of few microns, and can successfully characterize defects in the near-surf… more
Date: November 1, 1995
Creator: Asoka-Kumar, P.
Partner: UNT Libraries Government Documents Department
open access

Scintillating fiber tracking at high luminosities using Visible Light Photon counter readout

Description: This paper reviews the research work on the Visible Light Photon Counters (VLPC) that have been developed for the scintillating fiber tracking at high luminosity colliders and high rate fixed target experiments. The devices originated from the joint work between UCLA and Rockwell International Science Center. The VLPCs are capable of counting photons very efficiently down to a single photon level with high avalanche gain, producing pulses at very high rates with very short rise times. Due to sm… more
Date: November 1, 1995
Creator: Atac, M.
Partner: UNT Libraries Government Documents Department
open access

SVX/silicon detector studies

Description: AC coupled silicon detectors, being used for the DO upgrade, may have substantial voltage across the coupling capacitor. Failed capacitors can present {approximately}50 V to the input of the SVX, Silicon Vertex, device. We measured the effects that failed detector coupling capacitors have on the SVXD (rad soft 3{mu}m), SVXH (rad hard 1.2{mu}m), and SVXIIb (rad soft 1.2{mu}m) amplifier / readout devices. The test results show that neighboring channels saturate when an excessive voltage is applie… more
Date: November 1, 1995
Creator: Bagby, L.; Johnson, M.; Lipton, R. & Gu, W.
Partner: UNT Libraries Government Documents Department
open access

Crossover from dimer nucleation to adatom exchange during submonolayer epitaxy

Description: The nucleation and growth of islands in the early stages of epitaxial growth is studied with kinetic Monte Carlo Simulations and self-consistent mean field rate equations. Specifically, adatom exchange and irreversible dimer formation are allowed to compete equally as the origin of two-dimensional islands. The island size distribution and number density are found to satisfy a dynamic crossover scaling form. The critical island size evolves from one to zero with increasing temperature, decreasin… more
Date: November 1, 1995
Creator: Bales, G.S.
Partner: UNT Libraries Government Documents Department
open access

Underground nuclear waste containments

Description: In the United States, about a hundred million gallons of high-level nuclear waste are stored in underground containments. Basically, these containments are of two different designs: single-shell and double-shell structures. The single-shell structures consist of reinforced concrete cylindrical walls seated on circular mats and enclosed on top with torispherical domes or circular flat roofs. The walls and the basemats are lined with carbon steel. The double-shell structures provide another layer… more
Date: November 1, 1995
Creator: Bandyopadhyay, K.K.
Partner: UNT Libraries Government Documents Department
open access

Photocarrier relaxation in the quantum kinetics regime

Description: We present a study of carrier relaxation in GaAs in the quantum- kinetics regime. The results cannot be explained by Bolzmann kinetics. They are in satisfactory agreement with quantum-kinetic theory calculation of the occupation number in k-space.
Date: November 1, 1995
Creator: Bar-Ad, S.; Kner, P.; Chemla, D.S. & El Sayed, K.
Partner: UNT Libraries Government Documents Department
open access

Risk-Based Regulation: Challenges and Opportunities

Description: Over the last twenty years, man has witnessed a gradual but steady movement toward increased usage of risk-based methods and results in the regulatory process. The ``risk perspective`` as a supportive view to existing (non-risk-based or deterministic) information used in decision making has a firm foothold now in most countries that regulate nuclear power. Furthermore, in the areas outside the nuclear power field, such as health risk assessment, risk-based information is used increasingly to ma… more
Date: November 1, 1995
Creator: Bari, R. A.
Partner: UNT Libraries Government Documents Department
open access

TEOS-based SiO{sub 2} chemical vapor deposition: Reaction kinetics and related surface chemistry

Description: We have developed a comprehensive understanding of thermal TEOS (tetracthylorthosificate, Si(OCH{sub 2}CH{sub 3}){sub 4}) surface chemistry at CVD (chemical vapor deposition) temperatures and pressures. This was accomplished by examining how TEOS reaction rate are influenced by factors critical to the heterogeneous reaction. This includes determining the TEOS pressure dependence, testing if reaction by-products inhibit TEOS decomposition, identifying reaction sites on the surface, and establish… more
Date: November 1, 1995
Creator: Bartram, M. E. & Moffat, H. K.
Partner: UNT Libraries Government Documents Department
open access

Hot cell remote nuclear scanning of tank core samples

Description: A Westinghouse Hanford Company (WHC)-designed remote measurement system has been constructed for gamma and beta isotopic characterization of Hanford Site high-level waste tank core sample materials in a hot cell. A small, collimated, planar CdZnTe detector is used for gamma-ray spectroscopy. Spectral resolution of 2% full-width-at-maximum at 662 kiloelectronvolts (keV) has been obtained remotely using risetime compensation and limited pulse shape discrimination (PSD). Isotopic measurement of hi… more
Date: November 1995
Creator: Beck, M. A.; Blewett, G. R.; Troyer, G. L.; Keele, B. D. & Addleman, R. S.
Partner: UNT Libraries Government Documents Department
open access

Characterization and laboratory weathering studies

Description: Characterization studies of PFBC by-products were initiated to provide baseline information need to predict the behavior and suitability of PFBC by-products for beneficial uses. The chemical composition of the by-products was dominated by Ca, Mg, S, Fe, Al, and Si. All samples were highly alkaline with paste pH values ranging from 9.9 to 12.3. All of the PFBC materials met the criteria for pollutant ceiling concentrations for land application of sewage sludge for Cd, Cr, Cu, Pb, Mo, Ni, Se, and… more
Date: November 1, 1995
Creator: Beeghly, J.H.; Dick, W.A. & Fowler, R.K.
Partner: UNT Libraries Government Documents Department
open access

Performance of Low-Btu Fuel Gas Turbine Combustors

Description: This reports on a project to develop low BTU gas fuel nozzle for use in large gas turbine combustors using multiple fuel nozzles. A rich-quench-lean combustor is described here which reduces the amount of NO{sub x} produced by the combustion of the low BTU gas. The combustor incorporates a converging rich stage combustor liner, which separates the rich stage recirculation zones from the quench stage and lean stage air.
Date: November 1, 1995
Creator: Bevan, S.; Bowen, J. H.; Feitelberg, A. S.; Hung, S. L.; Lacey, M. A. & Manning, K. S.
Partner: UNT Libraries Government Documents Department
open access

Filter systems for IGCC applications

Description: The objectives of this program were to identify metallic filter medium to be utilized in the Integrated Gasification Combined Cycle process (IGCC). In IGCC processes utilizing high efficiency desulfurizing technology, the traditional corrosion attack, sulfidation, is minimized so that metallic filters are viable alternatives over ceramic filters. Tampa Electric Company`s Polk Power Station is being developed to demonstrate Integrated Gasification Combined Cycle technology. The Pall Gas Solid Se… more
Date: November 1, 1995
Creator: Bevan, S.; Gieger, R.; Sobel, N. & Johnson, D.
Partner: UNT Libraries Government Documents Department
open access

Uniaxial Compression Behavior of Small Blocks of Welded Tuff

Description: Laboratory compression tests have been conducted on small block samples of Topopah Spring Tuff to investigate the scale dependence of geomechanical properties. These tests are the first of a series of tests designed to study coupled processes in the near-field environment of a nuclear waste repository. This paper presents new deformation and elastic wave velocity data.
Date: November 16, 1995
Creator: Blair, S. C. & Berge, P. A.
Partner: UNT Libraries Government Documents Department
open access

Brillouin-enhanced four-wave-mixing phase conjugator with correction for material, thermal and birefringence aberrations and passive output control

Description: We have developed a laser system that incoroprates a vector phase conjugate mirror that corrects for both spatial and polarization distortions. The fractional output coupling can be varied mechanically from 0 to 100%.
Date: November 20, 1995
Creator: Bowers, M.W.; Hankla, A.K. & Boyd, R.W.
Partner: UNT Libraries Government Documents Department
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