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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
Electron positron factories (open access)

Electron positron factories

In this paper, we will first indicate the key issues in designing a B-factory and a {phi}-factory, and illustrate the approaches that are being followed to address them. In general, reaching the B-factory parameter regime offers the most challenges, so we will emphasize it here. Then we will consider an extrapolation of our present understanding of collider performance and assess the maximum luminosity that could be anticipated. To reach extremely high luminosity, it may be necessary to consider possibilities beyond the scope of standard'' approaches to collider design; a few illustrative examples are outlined. For both the present designs and the extrapolated parameters, R D activities in a few key areas are required; these areas are discussed in this paper also.
Date: December 1, 1990
Creator: Zisman, M. S.; Chattopadhyay, S.; Garren, A. A.; Lambertson, G. (Lawrence Berkeley Lab., CA (United States)); Bloom, E.; Corbett, W. J. et al.
System: The UNT Digital Library
An introduction to baryon violation in standard electroweak theory (open access)

An introduction to baryon violation in standard electroweak theory

I shall begin with a qualitative overview of the anomaly and B violation at zero and non-zero temperature, demonstrating how these processes may be understood on the back of an envelope. Then I shall discuss a part of the formalism necessary for doing calculations in more detail. Specifically, B violation is related to various solutions to the Euclidean equations of motion; instantons, sphalerons, and calorons (also called periodic instantons). The applicability of the various solutions may be understood by analogies with elementary quantum mechanics problems. Finally, I shall touch upon the computation of high-energy B violation mentioned above. 29 refs., 11 figs.
Date: December 1, 1990
Creator: Arnold, P.B.
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
Mechanical deformations and coherent transport in carbon nanotubes (open access)

Mechanical deformations and coherent transport in carbon nanotubes

Article on mechanical deformations and coherent transport in carbon nanotubes.
Date: December 15, 1999
Creator: Buongiorno Nardelli, Marco & Bernholc, Jerry
System: The UNT Digital Library
A new experimental limit on the electric dipole moment of the electron (open access)

A new experimental limit on the electric dipole moment of the electron

We describe a search for the electric dipole moment d{sub e} of the electron, carried out with {sup 205}Tl atoms in the ground state. The experiment makes use of the separated-oscillating-field magnetic-resonance method, laser state selection, fluorescence detection, and two counter-propagating atomic beams. Very careful attention is paid to systematic effects. The result for the atomic electric dipole moment is d{sub a} = (1.6 {plus minus} 5.0) {times} 10{sup {minus}24} e cm. If we assume the theoretical ratio d{sub a}/d{sub e} = {minus}600, this yields d{sub e} = ({minus}2.7 {plus minus} 8.3) {times} 10{sup {minus}27} e cm. 17 refs., 7 figs., 1 tab.
Date: December 1, 1990
Creator: Carlberg, C.; Gould, H. (Lawrence Berkeley Lab., CA (USA)); Abdullah, K.; Commins, E.D. & Ross, S.B. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Physics)
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
Physics at the Planck scale (open access)

Physics at the Planck scale

Effective supergravity theories suggested by superstrings can be explored to determine their potential for successfully describing both observed physics at zero temperature and an inflationary cosmology. An important ingredient in this study is the dynamics of gaugino condensation, which has been the subject of recent activity. 33 refs., 2 figs.
Date: December 6, 1990
Creator: Gaillard, M.K. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Physics)
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
Framework ordering in aluminophosphate molecular sieves studied by sup 27 Al double rotation NMR (open access)

Framework ordering in aluminophosphate molecular sieves studied by sup 27 Al double rotation NMR

Aluminum-27 Double Rotation NMR spectroscopy (DOR) has been used to investigate framework ordering in the aluminophosphate molecular sieves VPI-5, AlPO{sub 4}-5, and AlPO{sub 4}-8. Well resolved peaks in the {sup 27}Al DOR spectra of both hydrated and dehydrated VPI-5 allow isotropic shifts to be correlated with local framework structure. more distorted aluminum environments are reflected by broader lines in {sup 27}Al DOR spectra of AlPO{sub 4}-5 and AlPO{sub 4}-8.
Date: December 1, 1990
Creator: Chmelka, B.F.; Wu, Y.; Jelinek, R.; Davis, M.E. & Pines, A. (Lawrence Berkeley Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Chemistry)
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
Localized or Systemic {italic In Vivo} Heat-Inactivation of Human Immunodeficiency Virus (HIV): A Mathematical Analysis (open access)

Localized or Systemic {italic In Vivo} Heat-Inactivation of Human Immunodeficiency Virus (HIV): A Mathematical Analysis

Temperatures as low as 42 C, maintained for a little as 25 minutes, inactivate {approx}25% of HIV. Furthermore, human immunodeficiency virus (HIV)-infected T-cells are more sensitive to heat than healthy lymphocytes and susceptibility increases when the cells are pre-sensitized by exposure to tumor necrosis factor. Thus, induction of a whole-body hyperthermia, or hyperthermia specifically limited to tissues having a high viral load, are potential antiviral therapies for acquired immunodeficiency disease (AIDS). Accordingly, we incorporated therapeutic hyperthermia into an existing mathematical model which evaluates the interaction between HIV and CD4{sup +} T cells. Given the assumptions and limitations of this model, the results indicate that a daily therapy, reducing the population of actively infected cells by 40% or infectious virus by 50%, would effectively reverse the depletion of T cells. In contrast, a daily reduction of 20% of either actively infected cells or infectious virus would have a marginal effect. However, reduction by 20% of both actively infected cells and infectious virus could restore T cell numbers, assuming that permanent damage had not been inflicted on the thymus. Whole-body hyperthermia seems unlikely to be clinically useful, unless it can be induced non-invasively without general anesthesia. In contrast, heating directed specifically to …
Date: December 15, 1993
Creator: Pennypacker, Carl R.; Perelson, A.S.; Nys, N.; Nelson, G. & Sessler, D.I.
System: The UNT Digital Library
A Design Method for Multiple Tube Gas-Cooled Electrical Leads forthe g-2 Superconducting Magnets (open access)

A Design Method for Multiple Tube Gas-Cooled Electrical Leads forthe g-2 Superconducting Magnets

None
Date: December 15, 1994
Creator: Green, M. A.; Jia, L. X.; Addessi, L. J.; Cullen, J. R.; Esper, A. J. & and Meier, R. E.
System: The UNT Digital Library
SEPARATION OF TRITIATED WATER FROM WATER USING COMPOSITE MEMBRANES (open access)

SEPARATION OF TRITIATED WATER FROM WATER USING COMPOSITE MEMBRANES

The work in this task involves the use of composite membranes to remove tritium from contaminated water at DOE sites. Experience with membrane systems in industry indicates that they are inherently energy efficient. Furthermore, membrane technologies such as reverse-osmosis have been well developed for desalination and other industrial/municipal applications. Aromatic polyphosphazenes were chosen as the polymeric material for the membranes being investigated because they have excellent radiological, thermal, and chemical stability. The FY-96 effort is directed toward empirical delineation of a potential mechanism, providing a statistical approach to data acquisition, further mass balance determination, and a preliminary design for the module staged array.
Date: December 18, 1995
Creator: JB, DUNCAN & DA, NELSON
System: The UNT Digital Library
Generation of Femtosecond X-Rays by 90 degrees Compton Scattering (open access)

Generation of Femtosecond X-Rays by 90 degrees Compton Scattering

We propose Compton scattering of a short pulse visible laser beam by a low energy (but relativistic) electron beam at a right angle for generation of femtosecond x-rays. Simple analysis to determine the qualitative and quantitative characteristics of the x-ray pulse is presented.
Date: December 1, 1992
Creator: Kim, K. J.; Chattopadhyay, S. & Shank, C. V.
System: The UNT Digital Library
Use of Volatile Tracers to Determine the Contribution ofEnvironment Tobacco Smoke to Concentrations of Volatile Organic Compoundsin Smoking Environments (open access)

Use of Volatile Tracers to Determine the Contribution ofEnvironment Tobacco Smoke to Concentrations of Volatile Organic Compoundsin Smoking Environments

Three volatile nitrogen-containing compounds, 3-ethenylpyridine (3-EP), pyridine and pyrrole, were investigated as potential tracers for determining the contribution of environmental tobacco smoke (ETS) to concentrations of volatile organic compounds (VOCs) in indoor environments with smoking. The source emission rates of the three tracers and ten selected VOCs in ETS were first measured in a room-size environmental chamber for a market-weighted selection of six commercial cigarettes. The ratios of the emission rates of the tracers to the emission rates of the selected VOCs were calculated and compared among the six brands. The utility of the tracers was then evaluated in a field study conducted in five office buildings. Samples for VOCs were collected in designated smoking areas and adjoining non-smoking areas, air change rates were measured, and smoking rates were documented. Concentrations of the three tracers in the smoking areas were calculated using a mass-balance model and compared to their measured concentrations. Based on this comparison, 3-EP was selected as the most suitable tracer for the volatile components of ETS, although pyrrole is also potentially useful. Using 3-EP as the tracer, the contributions of ETS to the measured concentrations of the selected VOCs in the smoking areas were estimated by apportionment. …
Date: December 1, 1995
Creator: Hodgson, A. T.; Daisey, J. M.; Alevantis, L. E.; Mahanama, K. R. R. & Ten Brinke, J.
System: The UNT Digital Library
A site scale model for modeling unsaturated zone processes atYucca Mountain, Nevada (open access)

A site scale model for modeling unsaturated zone processes atYucca Mountain, Nevada

None
Date: December 15, 1997
Creator: Bodvarsson, G.S.; Wu, Y.S.; Sonnenthal, E.L.; Bandurraga, T.M.; Ahlers, C.F.; Haukwa, C. et al.
System: The UNT Digital Library
Improving plasma shaping accuracy through consolidation of control model maintenance, diagnostic calibration, and hardware change control (open access)

Improving plasma shaping accuracy through consolidation of control model maintenance, diagnostic calibration, and hardware change control

With the advent of more sophisticated techniques for control of tokamak plasmas comes the requirement for increasingly more accurate models of plasma processes and tokamak systems. Development of accurate models for DIII-D power systems, vessel, and poloidal coils is already complete, while work continues in development of general plasma response modeling techniques. Increased accuracy in estimates of parameters to be controlled is also required. It is important to ensure that errors in supporting systems such as diagnostic and command circuits do not limit the accuracy of plasma parameter estimates or inhibit the ability to derive accurate plasma/tokamak system models. To address this issue, we have developed more formal power systems change control and power system/magnetic diagnostics calibration procedures. This paper discusses our approach to consolidating the tasks in these closely related areas. This includes, for example, defining criteria for when diagnostics should be re-calibrated along with required calibration tolerances, and implementing methods for tracking power systems hardware modifications and the resultant changes to control models.
Date: December 1, 1995
Creator: Baggest, D. S.; Rothweil, D. A.; Pang, S.; Walker, M. L. & Nerem, A.
System: The UNT Digital Library