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Heavy flavor physics at hadron colliders (open access)

Heavy flavor physics at hadron colliders

The search for the top quark has dominated heavy flavor physics at hadron colliders. For Standard model decay of top the present mass limit in m{sub t} > 89 GeV (95% C.L.). Bottom production cross sections are quite large at hadron colliders, thus providing enough statistics for extensive studies. Results on cross sections, B{sup 0} {minus} {bar B}{sup 0} mixing, exclusive channels and rare B decays will be summarized.
Date: December 1, 1991
Creator: Barbaro-Galtieri, A.
System: The UNT Digital Library
Two-component flow study in large-diameter horizontal pipe (open access)

Two-component flow study in large-diameter horizontal pipe

Westinghouse Savannah River Company, Idaho National Engineering Laboratory, and Wyle Laboratory cooperated in a series of single- and two-component calibration tests conducted to obtain sufficient information for calibrating flowmeters, to observe flow patterns, and to estimate void functions. Testing, conducted in large-diameter horizontal pipe, covered total flows of 0.19 to 1.89 m{sup 3}/s (3000 to 30000 gpm) and inlet void fractions up to 40%. A flow regime map, constructed using video images of the flow patterns and void fraction data, was compared with maps from the literature, with generally good agreement for interpretation of flow patterns. 5 refs.
Date: December 3, 1991
Creator: Eghbali, D. A.
System: The UNT Digital Library
A kinetics study of the O( sup 3 P) + CH sub 3 Cl reaction over the 556-1485 K range by the HTP and LP-ST techniques (open access)

A kinetics study of the O( sup 3 P) + CH sub 3 Cl reaction over the 556-1485 K range by the HTP and LP-ST techniques

The high-temperature photochemistry (HTP) and laser photolysis-shock tube (LP-ST) techniques have been combined to study the kinetics of the reaction between ground-state oxygen atoms with CH{sub 3}Cl over the temperature range, 556--1485 K. In the HTP reactor, used for the 556--1291 K range, O atoms were generated by flash photolysis of O{sub 2}, CO{sub 2} or SO{sub 2}, and the atom concentrations were monitored by resonance fluorescence, while with the LP-ST technique, used for the 916--1485 K range, O atoms were generated by the photolysis of either SO{sub 2} or NO with the 193 nm light from a pulsed ArF excimer laser, and atomic resonance absorption spectroscopy (ARAS) was used to monitor (O){sub t}. In both studies, rate coefficients were derived from the (O) profiles under the pseudo-first-order condition, (O){much lt}(CH{sub 3}Cl). The data obtained by the two techniques are in excellent agreement and are best represented by the expression, k(T) = 2.57 {times} 10{sup {minus}11} (T/K){sup 0.31} exp({minus}5633 K/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} with a 2{sigma} precision varying from {plus minus}6 {plus minus}22% and an estimated 2{sigma} accuracy of {plus minus}21% to {plus minus}30%, depending on temperature. The rate coefficients for the title reaction are essentially identical …
Date: December 1, 1991
Creator: Ko, Taeho; Fontijn, A. (Rensselaer Polytechnic Inst., Troy, NY (United States). High-Temperature Reaction Kinetics Lab.); Lim, K.P. & Michael, J.V. (Argonne National Lab., IL (United States))
System: The UNT Digital Library
Materials performance in fluidized-bed air heaters (open access)

Materials performance in fluidized-bed air heaters

Development of cogeneration systems that involve combustion of coal in a fluidized bed and use of air heaters to generate hot air for turbine systems has been in progress for a number of years. The US Department of Energy (DOE) sponsored the Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) to assess the performance of various heat exchanger materials and establish confidence in the resultant designs of fluidized-bed-combustion air heater systems. Westinghouse Electric Corporation, in association with Babcock Wilcox, Foster Wheeler, and ABB/Combustion Engineering, prepared specifications and hardware for the ACAHE. Argonne National Laboratory, through a contract with the Rocketdyne Division of Rockwell International, conducted tests in the DOE 1.8 {times} 1.8 m atmospheric fluidized-bed combustion facility in El Segundo, California. This paper presents an assessment of the materials performance in fluidized bed environments and examines guidelines for materials selection on the basis of corrosion resistance in air and in combustion environments, mechanical properties, fabricability/thermal stability, and cost.
Date: December 1, 1991
Creator: Natesan, K. & Podolski, W.
System: The UNT Digital Library
Beryllium technology workshop, Clearwater Beach, Florida, November 20, 1991 (open access)

Beryllium technology workshop, Clearwater Beach, Florida, November 20, 1991

This report discusses the following topics: beryllium in the ITER blanket; mechanical testing of irradiated beryllium; tritium release measurements on irradiated beryllium; beryllium needs for plasma-facing components; thermal conductivity of plasma sprayed beryllium; beryllium research at the INEL; Japanese beryllium research activities for in-pile mockup tests on ITER; a study of beryllium bonding of copper alloy; new production technologies; thermophysical properties of a new ingot metallurgy beryllium product line; implications of beryllium:steam interactions in fusion reactors; and a test program for irradiation embrittlement of beryllium at JET.
Date: December 1, 1991
Creator: Longhurst, G.R.
System: The UNT Digital Library
Quantum Irreversibility and Chaos [Phys. Rev. Lett. 67, 2593 (1991)] (open access)

Quantum Irreversibility and Chaos [Phys. Rev. Lett. 67, 2593 (1991)]

Corrections to an equation printed with a typographical error in Quantum Irreversibility and Chaos, Physical Review Letters 67, 2593 (1991).
Date: December 23, 1991
Creator: Bonci, Luca; Roncaglia, Roberto; West, Bruce J. & Grigolini, Paolo
System: The UNT Digital Library
Photocathode transfer and storage techniques using alkali vapor feedback control (open access)

Photocathode transfer and storage techniques using alkali vapor feedback control

Photocathodes of quantum efficiency above 1% at the doubled YAG frequency of 532 nM are very sensitive to the local vacuum environment. These cathodes must have a band gap of less than 2.3 eV, and a work function that is also on the order of {approximately}2 volts or less. As such, these surfaces are very reactive as they provide many surface states for the residual gases that have positive electron affinities such as oxygen and omnipotent water. Attendant to this problem is that the optimal operating point for some of these cesium based cathodes is unstable. Three of the cesium series were tried, the Cs-Ag-Bi-O, the Cs{sub 3}Sb and the K{sub 2}CsSb. The most stable material found is the K{sub 2}CsSb. The vacuum conditions can be met by a variety of pumping schemes. The vacuum is achieved by using sputter ion diode pumps, and baking at 250{degrees}C or less for whatever time is required to reduce the pump currents to below 1 uA at room temperature. To obtain the required partial pressure of cesium, a simple very sensitive diagnostic gauge has been developed that can discriminate between free alkali and other gases present. This Pressure Alkali Monitor (PAM) can be …
Date: December 20, 1991
Creator: Springer, R.W. & Cameron, B.J.
System: The UNT Digital Library
[Edward and Betty Marcus Foundation award $225,000 to visual arts institute] (open access)

[Edward and Betty Marcus Foundation award $225,000 to visual arts institute]

A press release about the Edward and Betty Marcus Foundation awarding $225,000 in grants to North Texas Institute for Educators on the Visual Arts. The first payment of the three-year grant has already been paid for a total of $60,000, the foundation will give the institute an additional $75,000, January 1993 and the final $90,000 in January 1994. North Texas Institute for Educators on the Visual Arts is made of a consortia of school districts in the metroplex, museums and art councils whose primary goals it to provide intensive training in discipline-based art education and implementation in the schools curriculum.
Date: December 1991
Creator: Guest, Charlotte Menger
System: The UNT Digital Library
Hydrological and thermal issues concerning a nuclear waste repository in fractured rocks (open access)

Hydrological and thermal issues concerning a nuclear waste repository in fractured rocks

The characterization of the ambient conditions of a potential site and the assessment of the perturbations induced by a nuclear waste repository require hydrological and thermal investigations of the geological formations at different spatial and temporal scales. For high-level wastes, the near-field impacts depend on the heat power of waste packages and the far-field long-term perturbations depend on the cumulative heat released by the emplaced wastes. Surface interim storage of wastes for several decades could lower the near-field impacts but would have relatively small long-term effects if spent fuels were the waste forms for the repository. One major uncertainty in the assessment of repository impacts is from the variation of hydrological properties in heterogeneous media, including the effects of fractures as high-permeability flow paths for containment migration. Under stress, a natural fracture cannot be represented by the parallel plate model. The rock surface roughness, the contact area, and the saturation state in the rock matrix could significantly change the fracture flow. In recent years, the concern of fast flow through fractures in saturated media has extended to the unsaturated zones. The interactions at different scales between fractures and matrix, between fractured matrix unites and porous units, and between formations and …
Date: December 1, 1991
Creator: Wang, J.S.Y.
System: The UNT Digital Library
Reactor Operations Management Plan (open access)

Reactor Operations Management Plan

The K-Reactor last operated in April 1988. At that time, K-Reactor was one of three operating reactors at the Savannah River Site (SRS). Following an incident in P-Reactor in August 1988, it was decided to discontinue SRS reactor operation and conduct an extensive program to upgrade operating practices and plant hardware prior to restart of any of the reactors. The K-reactor was the first of three reactors scheduled to resume production. At the present time, it is the only reactor with planned restart. WSRC assumed management of SRS on April 1, 1989. WSRC established the Safety Basis for Restart and a listing of the actions planned to satisfy the Safety Basis. In consultation with DOE, it was determined that proper management of the restart activities would require a single plan that integrated the numerous activities. The plan was entitled the Reactor Operations Management Plan and is referred to simply as the ROMP. The initial version of ROMP was produced in July of 1989. Subsequent modifications led to Revision 3 which was approved by DOE in May, 1990. Other changes were made in a formal change process, resulting in the latest version, Revision 5, being issued in October, 1990. The ROMP …
Date: December 5, 1991
Creator: Rice, P.D.
System: The UNT Digital Library
Neutron skyshine from end stations of the Continuous Electron Beam Accelerator Facility (open access)

Neutron skyshine from end stations of the Continuous Electron Beam Accelerator Facility

The MORSE{ }CG code from Oak Ridge National Laboratory was applied to the estimation of the neutron skyshine from three end stations of the Continuous Electron Beam Accelerator Facility (CEBAF), Newport News, VA. Calculations with other methods and an experiment had been directed at assessing the annual neutron dose equivalent at the site boundary. A comparison of results obtained with different methods is given, and the effect of different temperatures and humidities will be discussed.
Date: December 1, 1991
Creator: Sun, Rai-Ko S.
System: The UNT Digital Library
The tau-charm factory: Concept and construction (open access)

The tau-charm factory: Concept and construction

The first part of this paper explains the tau-charm factory concept: a high luminosity, low-energy, two-ring, electron-positron collider which enables precise and probing studies of the physics of the charm quark, tau lepton, and tau neutrino. The second part describes the plans for construction of a tau-charm factory in Spain. 28 refs., 2 figs., 1 tab.
Date: December 1, 1991
Creator: Perl, M.L. & Niemi, G.D.
System: The UNT Digital Library
Polycrystalline thin-film solar cells and modules (open access)

Polycrystalline thin-film solar cells and modules

This paper describes the recent technological advances in polycrystalline thin-film solar cells and modules. Three thin film materials, namely, cadmium telluride (CdTe), copper indium diselenide (CuInSe{sub 2}, CIS) and silicon films (Si-films) have made substantial technical progress, both in device and module performance. Early stability results for modules tested outdoors by various groups worldwide are also encouraging. The major global players actively involved in the development of the these technologies are discussed. Technical issues related to these materials are elucidated. Three 20-kW polycrystalline thin-film demonstration photovoltaic (PV) systems are expected to be installed in Davis, CA in 1992 as part of the Photovoltaics for Utility-Scale Applications (PVUSA) project. This is a joint project between the US Department of Energy (DOE), Pacific Gas and Electric (PG E), Electric Power Research Institute (EPRI), California Energy Commission (CEC), and a utility consortium.
Date: December 1, 1991
Creator: Ullal, Harin S.; Stone, Jack L.; Zweibel, Kenneth; Surek, Thomas & Mitchell, Richard L.
System: The UNT Digital Library
Dynamic stall on wind turbine blades (open access)

Dynamic stall on wind turbine blades

Dynamic loads must be predicted accurately in order to estimate the fatigue life of wind turbines operating in turbulent environments. Dynamic stall contributes to increased dynamic loads during normal operation of all types of horizontal-axis wind turbine (HAWTs). This report illustrates how dynamic stall varies throughout the blade span of a 10 m HAWT during yawed and unyawed operating conditions. Lift, drag, and pitching moment coefficients during dynamics stall are discussed. Resulting dynamic loads are presented, and the effects of dynamic stall on yaw loads are demonstrated using a yaw loads dynamic analysis (YAWDYN). 12 refs., 22 figs., 1 tab.
Date: December 1, 1991
Creator: Butterfield, C.P.; Simms, D.; Scott, G. (National Renewable Energy Lab., Golden, CO (United States)) & Hansen, A.C. (Utah Univ., Salt Lake City, UT (United States))
System: The UNT Digital Library
The Federal Advanced Wind Turbine Program (open access)

The Federal Advanced Wind Turbine Program

The development of technologically advanced, higher efficiency wind turbines has been identified as a high priority activity by the US wind industry. The Department of Energy's Wind Energy Program has begun a multi-year development program aimed at assisting the wind industry with the design, development, and testing of advanced wind turbine systems that can compete with conventional electric generation for $0.05/kWh at 13 mph sites by the mid-1990s and with fossil-fuel-based generators for $0.04/kWh at 13 mph sites by the year 2000. The development plan consists of four phases: (1) Conceptual Design Studies; (2) Near-Term Product Development; (3) Next Generation Technology Integration and Design, and (4) Next- Generation Technology Development and Testing. The Conceptual Design Studies were begun in late 1990, and are scheduled for completion in the Spring of 1992. Preliminary results from these analyses are very promising and indicate that the goals stated above are technically feasible. This paper includes a brief summary of the Conceptual Design Studies and presents initial plans for the follow-on activities. 3 refs., 4 figs.
Date: December 1, 1991
Creator: Hock, S M; Thresher, R W & Goldman, P R
System: The UNT Digital Library
Software development for a switch-based data acquisition system (open access)

Software development for a switch-based data acquisition system

We report on the software aspects of the development of a switch-based data acquisition system at Fermilab. This paper describes how, with the goal of providing an integrated systems engineering'' environment, several powerful software tools were put in place to facilitate extensive exploration of all aspects of the design. These tools include a simulation package, graphics package and an Expert System shell which have been integrated to provide an environment which encourages the close interaction of hardware and software engineers. This paper includes a description of the simulation, user interface, embedded software, remote procedure calls, and diagnostic software which together have enabled us to provide real-time control and monitoring of a working prototype switch-based data acquisition (DAQ) system.
Date: December 1, 1991
Creator: Booth, A. (Superconducting Super Collider Lab., Dallas, TX (United States)); Black, D. & Walsh, D. (Fermi National Accelerator Lab., Batavia, IL (United States))
System: The UNT Digital Library
The physics of proton antiproton collisions (open access)

The physics of proton antiproton collisions

This paper contains information information on: accelerator and detector; QCD studies; studies of the electroweak force; The search for the top quark; {beta} physics at hadron colliders; and the search for exotic objects and prospects for the future.
Date: December 3, 1991
Creator: Shochet, M. (Chicago Univ., IL (United States))
System: The UNT Digital Library
The physics of strange matter (open access)

The physics of strange matter

Strange matter may be the ground state of matter. We review the phenomenology and astrophysical implications of strange matter, and discuss the possible ways for testing the strange matter hypothesis.
Date: December 1, 1991
Creator: Olinto, A. V.
System: The UNT Digital Library
Thermal treatment of refinery wastes for oil recovery: The PST process (open access)

Thermal treatment of refinery wastes for oil recovery: The PST process

Pacific Northwest Laboratory (PNL) has been investigating thermal, high-pressure processing of organic waste streams. The range of research and development activities extends from fundamental studies of conversion of biomass, coal, and organic wastes in high-pressure aqueous environments to tests in small pilot-scale reactor systems. Several processes have been developed from these investigations including two that have already been licensed to private companies. The most recently developed process is the Petroleum Sludge Treatment (PST) system which separates and recovers oil and water from oil-in-water emulsions such as the US Environmental Protection Agency (EPA) K'' listed wastes. The PST process evolved from attempts to convert API and DAF sludges to methane gas using the Thermochemical Environmental Energy System process. We were unsuccessful in converting these sludges to methane, however it became evident that thermal, high-pressure processing was very effective in separating the components of these sludges. The concept was further investigated and refined and the PST process was granted a US Patent in 1990.
Date: December 1, 1991
Creator: Baker, E. G.; Elliott, D. C. & Sealock, L. J. Jr.
System: The UNT Digital Library
Flame front geometry in premixed turbulent flames (open access)

Flame front geometry in premixed turbulent flames

Experimental and numerical determinations of flame front curvature and orientation in premixed turbulent flames are presented. The experimental data is obtained from planar, cross sectional images of stagnation point flames at high Damkoehler number. A direct numerical simulation of a constant energy flow is combined with a zero-thickness, constant density flame model to provide the numerical results. The computational domain is a 32{sup 3} cube with periodic boundary conditions. The two-dimensional curvature distributions of the experiments and numerical simulations compare well at similar q{prime}/S{sub L} values with means close to zero and marked negative skewness. At higher turbulence levels the simulations show that the distributions become symmetric about zero. These features are also found in the three dimensional distributions of curvature. The simulations support assumptions which make it possible to determine the mean direction cosines from the experimental data. This leads to a reduction of 12% in the estimated flame surface area density in the middle of the flame brush. 18 refs.
Date: December 1, 1991
Creator: Shepherd, I.G. (Lawrence Berkeley Lab., CA (United States)) & Ashurst, W.T. (Sandia National Labs., Livermore, CA (United States))
System: The UNT Digital Library
Cost comparison of solar detoxification with conventional alternatives for the destruction of trichloroethylene (open access)

Cost comparison of solar detoxification with conventional alternatives for the destruction of trichloroethylene

The purpose of this analysis is to compare the cost of solar waste detoxification processes with conventional alternatives for the treatment of trichloroethylene (TCE) in air. The solar processes that were evaluated are high flux photothermal oxidation (PHOTOX), high flux thermal catalytic reforming (SOLTOX), and low flux photocatalytic oxidation (PHOCAT). The high flux processes, PHOTOX and SOLTOX, were based on dish concentrator technology. The low flux photocatalytic process was based on parabolic trough concentrating technology. The conventional alternatives are thermal oxidation, thermal catalytic oxidation, off-site carbon regeneration, and on-site solvent recovery. Analysis of the seven processes showed PHOCAT to be the most economical treatment method. PHOTOX showed slightly better economics relative to SOLTOX. Both were competitive, with the best conventional destruction process, thermal oxidation. Off-site carbon regeneration was the most expensive treatment method. 9 refs., 7 figs.
Date: December 1, 1991
Creator: Glatzmaier, G.C.
System: The UNT Digital Library
Chiral symmetry breaking in gauge theories from Reggeon diagram analysis (open access)

Chiral symmetry breaking in gauge theories from Reggeon diagram analysis

It is argued that reggeon diagrams can be used to study dynamical properties of gauge theories containing a large number of massless fermions. SU(2) gauge theory is studied in detail and it is argued that there is a high energy solution which is analogous to the solution of the massless Schwinger model. A generalized winding-number condensate produces the massless pseudoscalar spectrum associated with chiral symmetry breaking and a trivial'' S-Matrix.
Date: December 16, 1991
Creator: White, A. R.
System: The UNT Digital Library
Infrared imaging results of an excited planar jet (open access)

Infrared imaging results of an excited planar jet

Planar jets are used for many applications including heating, cooling, and ventilation. Generally such a jet is designed to provide good mixing within an enclosure. In building applications, the jet provides both thermal comfort and adequate indoor air quality. Increased mixing rates may lead to lower short-circuiting of conditioned air, elimination of dead zones within the occupied zone, reduced energy costs, increased occupant comfort, and higher indoor air quality. This paper discusses using an infrared imaging system to show the effect of excitation of a jet on the spread angle and on the jet mixing efficiency. Infrared imaging captures a large number of data points in real time (over 50,000 data points per image) providing significant advantages over single-point measurements. We used a screen mesh with a time constant of approximately 0.3 seconds as a target for the infrared camera to detect temperature variations in the jet. The infrared images show increased jet spread due to excitation of the jet. Digital data reduction and analysis show change in jet isotherms and quantify the increased mixing caused by excitation. 17 refs., 20 figs.
Date: December 1, 1991
Creator: Farrington, R. B.
System: The UNT Digital Library
A first look at erosion of continuous-fiber reinforced ceramic-matrix composites (open access)

A first look at erosion of continuous-fiber reinforced ceramic-matrix composites

We report the initial results of a study of solid-particle erosion of Nicalon{trademark} Sic reinforced carbon-modified-silica-glass composites. SiC abrasives with diameters between 42 to 390{mu}m were used with impact angles of 30{degrees} and 90{degrees}, and velocities ranged 30 to 80 m/s. Fibers were parallel to the surface in all cases. Woven-fiber composites exhibited the same erosive behavior as uniaxial composites. Interfacial chemistry was controlled, and the comparison between composites which exhibit low-strength-brittle and high-strength-fibrous fractures under flexure conditions showed no significant difference in erosion resistance. This result and SEM data indicate that most of the fracture occurs within the matrix and/or at the fiber-matrix interface. We have found in previous work that polymer-matrix composites (with fibers parallel to the surface) are more susceptible to erosion damage than the matrix polymer. This also appears to be the case for the ceramic composites.
Date: December 1, 1991
Creator: Karasek, K. R.; Gonczy, S. T.; Kupperman, J. B.; Zamirowski, E. J.; Goretta, K. C. & Routbort, J. L.
System: The UNT Digital Library