Symmetry breaking: The standard model and superstrings (open access)

Symmetry breaking: The standard model and superstrings

The outstanding unresolved issue of the highly successful standard model is the origin of electroweak symmetry breaking and of the mechanism that determines its scale, namely the vacuum expectation value (vev)v that is fixed by experiment at the value v = 4m//sub w//sup 2///g/sup 2/ = (..sqrt..2G/sub F/)/sup /minus/1/ approx. = 1/4 TeV. In this talk I will discuss aspects of two approaches to this problem. One approach is straightforward and down to earth: the search for experimental signatures, as discussed previously by Pierre Darriulat. This approach covers the energy scales accessible to future and present laboratory experiments: roughly (10/sup /minus/9/ /minus/ 10/sup 3/)GeV. The second approach involves theoretical speculations, such as technicolor and supersymmetry, that attempt to explain the TeV scale. 23 refs., 5 figs.
Date: August 31, 1988
Creator: Gaillard, M. K.
Object Type: Article
System: The UNT Digital Library
Reminiscences of a particle physicist (open access)

Reminiscences of a particle physicist

This paper discusses some historical aspects of particle physics. (LSP)
Date: August 31, 1988
Creator: Goldhaber, M.
Object Type: Article
System: The UNT Digital Library
Prospects of TEVATRON upgrade (open access)

Prospects of TEVATRON upgrade

Following a brief review of the 1987 Fermilab collider run and the present status of the 1988 run, upgrade plans for the near-term (1988-1992) are described. For further luminosity upgrades beyond 1992, several scenarios are currently being discussed, one of which includes the construction of two new 20 GeV rings which could raise the proton-antiproton collider luminosity by a factor of 50 over the original Tevatron I design. Another possible project, the construction of a high luminosity proton-proton collider, has also been investigated in detail. A third scenario, involving a new Main Injector to replace the Main Ring and a new higher energy superconducting synchrotron, is presently being examined. It is hoped that this will result in a proposal to be submitted to DOE for FY91. The major issues concerning these options are presented. 8 figs., 1 tab.
Date: August 31, 1988
Creator: Syphers, M.J.
Object Type: Article
System: The UNT Digital Library
Writing SUBROUTINE HOWFAR for EGS4 (open access)

Writing SUBROUTINE HOWFAR for EGS4

The purpose of this note is to provide guidance, in addition to that given in SLAC-265, in writing SUBROUTINE HOWFAR for both simple and complex geometrical situations. Since most complex geometries can be represented in terms of blocks of simpler geometries, a number of geometry subprograms have been created for use within HOWFAR. They are provided as part of the EGS4 Code System, which means that they are located in files on the EGS4 disk under VM/SP at SLAC. They are also on the EGS4 Distribution Tape that is given out on request by the SLAC Radiation Physics Group. What we hope to accomplish with this note is to show how to create EGS4 geometries in a modular fashion, with particular emphasis on using the macro equivalents of the subroutines in order to gain efficiency. It is assumed that the reader is already familiar with EGS4 and understands the role of the variables USTEP, IDISC, and IRNEW as they apply to SUBROUTINE HOWFAR. If not, then the reader is advised to study Appendix 2 of SLAC-265 first. The tutorial chapter may also provide some insight. 5 refs., 10 figs.
Date: August 31, 1988
Creator: Nelson, W. R. & Jenkins, T. M.
Object Type: Report
System: The UNT Digital Library
Development of a 10-decade single-mode reactor flux monitoring system (open access)

Development of a 10-decade single-mode reactor flux monitoring system

Conventional wide-range neutron channels employ three optional modes to monitor the required flux range from source levels to full power (typically 10 or more decades). Difficult calibrations are necessary to provide a continuous output signal when such a system switches from counting mode in the source range to mean-square voltage mode in the midrange to dc current mode in the power range. In an ORNL proof-of-principle test, a method of extended range counting was implemented with a fission counter and conventional wide-band pulse processing electronics to provide a single-mode, monotonically increasing signal that spanned /approximately 10/ decades of neutron flux. Ongoing work includes design, fabrication, and testing of a comlpete neutron flux monitoring system suitable for advanced liquid metal reactor designs. 6 refs., 4 figs.
Date: March 31, 1988
Creator: Valentine, K.H.; Shepard, R.L.; Falter, K.G. & Reese, W.B.
Object Type: Article
System: The UNT Digital Library
Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst. [Quarterly] report, October 1, 1988--December 31, 1988 (open access)

Slurry phase Fischer-Tropsch synthesis: Cobalt plus a water-gas shift catalyst. [Quarterly] report, October 1, 1988--December 31, 1988

A cobalt Fischer-Tropsch catalyst (CO/MgO/silica) was reduced and slurried in combination with reduced Cu/ZnO/Al{sub 2}0{sub 3} water-gas-shift catalyst. Combined catalyst system was run at fixed process conditions for more than 400 hours. The system showed stable selectivity. The Cu/ZnO/Al{sub 2}0{sub 3} water-gas-shift catalyst remained reasonably active in the presence of the cobalt catalyst. Hydrocarbon selectivity of the cobalt and Cu/ZnO/Al{sub 2}0{sub 3} catalyst system compared favorably to selectivity of iron-based catalysts. Methane selectivity was slightly higher for the cobalt-based system, but C{sub 5}{sup +} selectivity was essentially the same. The hydrocarbon product distribution appeared to exhibit a double-a behavior. a{sub 1} was near 0.80 which is higher than that of iron catalysts, while a{sub 2} was calculated to be 0.86 which is somewhat lower than would be typical for an iron-based catalyst.
Date: December 31, 1988
Creator: Yates, I. C. & Satterfield, C. N.
Object Type: Report
System: The UNT Digital Library
Pyrolysis and gasification of coal at high temperatures. Quarterly progress report No. 2, December 15, 1987--March 15, 1988 (open access)

Pyrolysis and gasification of coal at high temperatures. Quarterly progress report No. 2, December 15, 1987--March 15, 1988

The effects of particle size on the macropore structure of chars produced from an Illinois No. 6 coal were investigated. Three size fractions (100--120, 50--60 and 25--28 mesh) of coal particles were pyrolyzed in our captive-sample reactor at 10{degrees}C/s. By analyzing digitized particle cross-sections, we obtained the macropore volume distributions and surface areas, and determined that all three char samples had almost equal macroporosities. we have also analyzed for the first time the shape or boundary tortuosity of the macropores. As the size of the pyrolyzed coal particles increased, the produced chars exhibited macropores with more tortuous boundaries. Tortuous pore boundaries result in higher values for the true macropore surface areas and should enhance the reactivity of the char samples. A systematic procedure was developed for analyzing and averaging the simulation results obtained with our erosion models. Such a procedure is necessary for comparing statistical model predictions to experimental data. Several simulations were carried out to investigate the gasification behavior of the three char samples mentioned above and the predicted reactivity patterns are presented. Finally, a thermogravimetric analyzer (TGS-2) was ordered and will soon be delivered to our laboratory.
Date: December 31, 1988
Creator: Zygourakis, K.
Object Type: Report
System: The UNT Digital Library
Calculation of radiation dose rates from a spent nuclear fuel shipping cask (open access)

Calculation of radiation dose rates from a spent nuclear fuel shipping cask

Radiation doses from a spent nuclear fuel cask are usually from various phases of operations during handling, shipping, and storage of the casks. Assessment of such doses requires knowledge of external radiation dose rates at various locations surrounding a cask. Under current practices, dose rates from gamma photons are usually estimated by means of point- or line-source approaches incorporating the conventional buildup factors. Although such simplified approaches may at times be easy to use, their accuracy has not been verified. For example, those simplified methods have not taken into account influencing factors such as the geometry of the cask and the presence of the ground surface, and the effects of these factors on the calculated dose rates are largely unknown. Moreover, similar empirical equations for buildup factors currently do not exist for neutrons. The objective of this study is to use a more accurate approach in calculating radiation dose rates for both neutrons and gamma photons from a spent fuel cask. The calculation utilizes the more sophisticated transport method and takes into account the geometry of the cask and the presence of the ground surface. The results of a detailed study of dose rates in the near field (within 20 …
Date: December 31, 1988
Creator: Chen, S. Y. & Yuan, Y. C.
Object Type: Article
System: The UNT Digital Library
Energy transfer processes in solar energy conversion. Progress report, January 1, 1988--December 31, 1988 (open access)

Energy transfer processes in solar energy conversion. Progress report, January 1, 1988--December 31, 1988

The program involves the investigation of excitation transport and electron transfer in complex systems. In the area of electron transfer, we have been studying electron back transfer following donor-acceptor photoinduced electron transfer. We are addressing this problem both theoretically and experimentally. In the area of excitation transport, we have been examining transport in solid solutions, liquid solutions, and in clustered excitation transport systems. Again, we are pursuing both experimental and theoretical approaches. The problem of electron back transfer between photogenerated ions is of central importance in both artificial and biological solar energy conversion. Once an electron has been transferred from an optically excited donor to an acceptor, back transfer competes with the ability of the radical ions to go on to do useful chemistry. We are studying the back transfer process using picosecond transient grating experiments in conjunction with time resolved and steady state fluorescence quenching measurements. The transient grating experiments makes the back transfer process a direct experimental observable, while the fluorescence experiments allow the forward transfer to be examined. By combining the experiments, a complete picture emerges. 10 refs.
Date: December 31, 1988
Creator: Fayer, M. D.
Object Type: Report
System: The UNT Digital Library
Development of the chemical and electrochemical coal cleaning process. First quarterly technical progress report, April 1, 1988--June 30, 1988 (open access)

Development of the chemical and electrochemical coal cleaning process. First quarterly technical progress report, April 1, 1988--June 30, 1988

The objectives of this effort are (a) to learn the mechanisms by which the Chemical and Electrochemical Coal Cleaning (CECC) process removes pyritic sulfur and ash from coal, (b) to learn more about the operating parameters of the process, (c) to collect engineering information for scale-up of the process, and (d) to test the CECC process on a bench-scale continuous operation.
Date: December 31, 1988
Creator: Yoon, R. H.
Object Type: Report
System: The UNT Digital Library
Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Sixth quarterly technical progress report, 1 January--31 March 1988 (open access)

Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Sixth quarterly technical progress report, 1 January--31 March 1988

The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst comparisons. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.
Date: December 31, 1988
Creator: Withers, H. P.; Bukur, D. B. & Rosynek, M. P.
Object Type: Report
System: The UNT Digital Library
Arctic hydrology and meteorology. Annual report (open access)

Arctic hydrology and meteorology. Annual report

The behavior of arctic ecosystems is directly related to the ongoing physical processes of heat and mass transfer. Furthermore, this system undergoes very large fluctuations in the surface energy balance. The buffering effect of both snow and the surface organic soils can be seen by looking at the surface and 40 cm soil temperatures. The active layer, that surface zone above the permafrost table, is either continually freezing or thawing. A large percentage of energy into and out of a watershed must pass through this thin veneer that we call the active layer. Likewise, most water entering and leaving the watershed does so through the active layer. To date, we have been very successful at monitoring the hydrology of Imnavait Creek with special emphasis on the active layer processes. The major contribution of this study is that year-round hydrologic data are being collected. An original objective of our study was to define how the thermal and moisture regimes within the active layer change during an annual cycle under natural conditions, and then to define how the regime will be impacted by some imposed terrain alteration. Our major analysis of the hydrologic data sets for Imnavait Creek have been water balance …
Date: December 31, 1988
Creator: Kane, D. L.
Object Type: Report
System: The UNT Digital Library
Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Quarterly technical progress report, 1 July--30 September 1988 (open access)

Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Quarterly technical progress report, 1 July--30 September 1988

The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (F-T) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.
Date: December 31, 1988
Creator: Withers, H. P.; Bukur, D. B. & Rosynek, M. P.
Object Type: Report
System: The UNT Digital Library
[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, September 1--November 30, 1988 (open access)

[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, September 1--November 30, 1988

Work this quarter was devoted to initiating the coordinated experimental and theoretical/computational modeling study of CuO dispersed on alumina for adsorption of sulfur oxide gases. Research was devoted to characterizing CuO itself, as well as sulfur model compounds for benchmark comparisons, and toward modeling of copper site locations for dispersion on alumina.
Date: December 31, 1988
Creator: Cooper, B. R. & Montano, P. A.
Object Type: Report
System: The UNT Digital Library
Energy flow in an arctic aquatic ecosystem (open access)

Energy flow in an arctic aquatic ecosystem

Natural isotope abundances to trace major pathways of energy flow to consumers in Imnavait Creek and the tundra ecosystem of the R4D watershed with comparative work in the coastal tundra. Our overall goals are to a determine if carbon is accumulating in upland and coastal tundra; determine the role of eroded peat carbon in the aquatic ecosystem; and to determine the distribution of carbon and nitrogen isotopes in the tundra-pond ecosystem to establish the feasibility of using natural differences as tracers. Past work on fishes, birds, and the prey species of insects and aquatic crustaceans has shown that peat carbon is very important in the energy supply supporting the food webs over the course of the year. Obligate freshwater fishes from the coastal lakes and Colville River have been shown to contain up to 60 percent peat carbon at the end of the winter season. In contrast, migratory shorebirds and passerines contained much smaller radiocarbon abundances in summer, indicating a major shift to recent in situ primary production in pond and stream ecosystems in summer months. For the past two years, we have narrowed our focus to the processes supplying carbon to the beaded stream system at MS-117 and have …
Date: December 31, 1988
Creator: Schell, D. M.
Object Type: Report
System: The UNT Digital Library
Long-range forces and the collisions of free-molecular and transition regime aerosols (open access)

Long-range forces and the collisions of free-molecular and transition regime aerosols

An aerosol here is understood to be a two-component system comprised of gaseous and condensed phases with the characteristic that the condensed phase is not an equilibrium subsystem. In contrast to the usual definitions based upon geometrical or mechanical variables, this quasi-thermodynamic formulation is framed to emphasize the dynamical behavior of aerosols by allowing for coagulation and other aerosol evolutionary processes as natural consequences of the interactions and state variables appropriate to the system. As will become clear later, it also provides a point of departure for distinguishing aerosol particles from unstable gas-phase cluster systems. The question of accommodation in particle collisions must be addressed as a prelude to the discussion of the role of long-range forces. Microscopic reversibility is frequently assumed for molecular collisions with either molecules or solid surfaces. In the case of aerosol collisions, the implication of this assumption is that collisions are elastic, which is contrary to the evidence from coagulation experiments and the conventional operational assumption of sticking upon collision. Gay and Berne have performed computer simulations of the collision of two clusters consisting of a total of 135 molecules interacting via Lennard-Jones potentials. That work showed that complete accommodation, accompanied by overall heating of …
Date: December 31, 1988
Creator: Marlow, W. H.
Object Type: Article
System: The UNT Digital Library
Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Quarterly technical progress report, 1 October--31 December 1988 (open access)

Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Quarterly technical progress report, 1 October--31 December 1988

The objective of this contract is to develop a consistent technical data base on the use of iron-based catalysts in Fischer-Tropsch (FT) synthesis reactions. This data base will be developed to allow the unambiguous comparison of the performance of these catalysts with each other and with state-of-the-art iron catalyst compositions. Particular attention will be devoted to generating reproducible kinetic and selectivity data and to developing reproducible improved catalyst compositions.
Date: December 31, 1988
Creator: Withers, H. P.; Bukur, D. B. & Rosynek, M. P.
Object Type: Report
System: The UNT Digital Library
Advanced alternate planar geometry solid oxide fuel cells. Third interim quarterly technical progress report, July 1, 1988--September 30, 1988 (open access)

Advanced alternate planar geometry solid oxide fuel cells. Third interim quarterly technical progress report, July 1, 1988--September 30, 1988

The following Ceramatec tasks are reported: electrolyte development and fabrication, edge seal development/fabrication, electrode, and interconnector. The following IGT tasks are reported: cell design analysis, and program liaison and test facility preparation.
Date: December 31, 1988
Creator: Prouse, D.; Elangovan, S.; Khandkar, A.; Donelson, R. & Marianowski, L.
Object Type: Report
System: The UNT Digital Library
Multivariable and distributed control of nonlinear chemical processes using adaptive methods. Final report, February 1, 1985--January 31, 1988 (open access)

Multivariable and distributed control of nonlinear chemical processes using adaptive methods. Final report, February 1, 1985--January 31, 1988

In this work we studied the application of adaptive learning and optimization to chemical process control. The work covered theory as well as practical applications of adaptive and nonlinear control, including multivariable periodic control The main findings were: 1. Linear adaptive control systems may display chaotic behavior. The chaos has small amplitude if the algorithm is properly implemented. 2. Stability theory for nonlinear adaptive control has been developed. 3. Experimental evaluation of predictive control was performed. 4. A theory for periodic control and adaptive periodic control of chemical processes was developed.
Date: December 31, 1988
Creator: Ydstie, B. E.
Object Type: Report
System: The UNT Digital Library
Inertial Confinement Fusion Program. Progress report, FY 1988 (open access)

Inertial Confinement Fusion Program. Progress report, FY 1988

The results of two experiments carried out during this report period are briefly described. The first studied the effect of 151 on the Raman instability using half-micron laser light, and the results were compared with earlier NRL studies with one micron laser light. It was learned that Raman experiments and theory are in agreement if one uses 151 optics. The second experimental attempted to measure the growth rate of the Rayleigh-Taylor instability using half micron laser light.
Date: December 31, 1988
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Acoustic microscopy with mixed-mode transducers (open access)

Acoustic microscopy with mixed-mode transducers

The new amplitude-phase acoustic microscope is versatile; it operates in a wide frequency range 1--200 MHz, with selection of longitudinal, shear, and mixed modes. This enables it to be used in many NDE applications for different kinds of materials. Besides the application examples presented in this paper (bulk defect imaging of lossy materials or at deep locations; leads of IC chip in epoxy package; amplitude images of surface crack on Si nitride ball bearing; thin Au film on quartz), this system can also be applied for residual stress and anisotropy mapping with high accuracy and good spatial resolution. 7 refs, 6 figs.
Date: December 31, 1988
Creator: Chou, C. H.; Parent, P. & Khuri-Yakub, B. T.
Object Type: Article
System: The UNT Digital Library
Advanced Water-Cooled Phosphoric Acid Fuel Cell Development. Quarterly technical progress report No. 5, July--September 1988 (open access)

Advanced Water-Cooled Phosphoric Acid Fuel Cell Development. Quarterly technical progress report No. 5, July--September 1988

The initial conceptual design configuration was completed. Baseline on-site electrodes were tested at electric utility conditions in 2 x 2 inch cells. GSB-18P cathodes were fabricated. Design of small area development stack was initiated and long lead time items ordered. Molded cooler thermal cycling tests were initiated. Equipment to evaluate alternative manifold coating processes and materials were procured.
Date: December 31, 1988
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Studies of Coupled Chemical and Catalytic Coal Conversion Methods. Fifth Quarterly Report, October--December 1988 (open access)

Studies of Coupled Chemical and Catalytic Coal Conversion Methods. Fifth Quarterly Report, October--December 1988

Liquefaction of coal by depolymerization in an organic solvent has been studied for several years. The liquefied coal extract which results from such a process is far more suitable for conversion into liquid fuel by hydrogenolysis than is the untreated coal. Investigations on the chemical structure and the reactive sites of coal can help to select useful reactions for the production of liquids from coal. Sternberg et al. demonstrated that the reductive alkylation method transforms bituminous coal into an enormously soluble substance, irrespective of the mild reaction conditions. The effectiveness of newly introduced alkyl groups for the disruption of intermolecular hydrogen bonds and pi-pi interactions between the aromatic sheets in coal macromolecules has been recognized. It has been reported by Ignasiak et al. that a C-alkylabon reaction using sodium or potassium amide in liquid ammonia can be used to introduce alkyl groups at acidic carbon sites. A method has been developed recently in this laboratory for the solubilization of high rank coals. In the previous reports it was shown that n-butyl lithium and potassium t-butoxide in refluxing heptane produced coal anions which could be alkylated with different alkyl halides. Such alkylated coals were soluble up to 92% in solvents like …
Date: December 31, 1988
Creator: Stock, L. M.
Object Type: Report
System: The UNT Digital Library
Photovoltaic systems for export application. Informal report (open access)

Photovoltaic systems for export application. Informal report

One approach to improving the competitiveness of photovoltaic systems is the development of designs specifically for export applications. In other words, where is it appropriate in a system design to incorporate components manufactured and/or assembled in the receiving country in order to improve the photovoltaic exports from the US? What appears to be needed is a systematic method of evaluating the potential for export from the US of PV systems for various application in different countries. Development of such a method was the goal of this project.
Date: January 31, 1988
Creator: Duffy, J.; Campbell, H.; Sajo, A. & Sanz, E.
Object Type: Report
System: The UNT Digital Library