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Exploring novel silicon-containing polymers---From preceramic polymers to conducting polymers with nonlinear optical properties

Description: Several new types of silicon-containing preceramic polymers, i.e., poly(diorganosilacetylene) and poly(diorganosilvinylene) have been synthesized with molecular weights from 10,000 to 120,000. These polymers could be thermally converted to SiC with a moderate to high char yields. Ready solubility and good processability made these types of polymers attractive in their applications to ceramics. The thermal polymerization of diethynyldiphenyl-silane, which was reported in 1968 to afford poly(diph… more
Date: October 7, 1991
Creator: Pang, Yi.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Fresh-Bunch' technique in FELs

Description: The 'Fresh Bunch' technique is being proposed as a method of increasing the gain and power of FEL amplifiers in which the length of the optical radiation pulse is shorter than the length of the electron bunch. In multi-stage FEL, electron beam energy spread is increased by the FEL interaction in the early stages. In the 'Fresh Bunch' technique, the low energy spread of the electron beam is recovered by shifting the radiation pulse to an undisturbed part of the electron bunch, thus improving the… more
Date: January 1, 1991
Creator: Ben-Zvi, Ilan; Yang, K. M. & Yu, L. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A search for the production of the final states. tau. sup +. tau. sup minus e sup + e sup minus ,. tau. sup +. tau. sup minus. mu. sup +. mu. sup minus , and. tau. sup +. tau. sup minus. pi. sup +. pi. sup minus in e sup + e sup minus collisions at radical s = 29 GeV

Description: We have searched for the reaction e{sup +}e{sup {minus}} {yields} {tau}{sup +}{tau}{sup {minus}}{bar f}f, where f is either an electron, muon, or charged pion, at {radical}s = 29 GeV using the Mark 2 detector at the PEP storage ring. One candidate event is found while 2.3 events are expected from known processes. We would expect to see 11 events if the cross-section for e{sup +}e{sup {minus}} {yields} {tau}{sup +}{tau}{sup {minus}}{bar f}f at {radical}s = 29 GeV were enhanced by the factor of 4… more
Date: July 1, 1991
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Techniques and processes for the measurement of the resonances of small single crystals

Description: The mechanical resonances of small oriented single crystals of materials of interest to basic science and engineering can be used to determine all the elastic moduli and the ultrasonic attenuation of these materials. To measure the resonances of the samples without introducing the resonances of the measuring system requires that the transducers be non-resonant at the frequencies of interest, and that they be well isolated from their mounts. However, for samples near 1 mm in the largest dimensio… more
Date: January 1, 1991
Creator: Migliori, A.; Stekel, A.; Sarrao, J.L.; Visscher, W.M.; Bell, T. & Lei, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Reactivity of Young Chars via Energetic Distribution Measurements

Description: In this report, we present some preliminary work performed on the effect of CO{sub 2} partial pressure on temperature programmed desorption spectra from CO{sub 2}-oxidized chars. The following was accomplished during the reporting period: Temperature programmed desorption (TPD) experiments were conducted on oxidized resin and Wyodak coal char samples gasified under varying different CO{sub 2} partial pressures. The following observations were made: CO{sub 2} partial pressure can be an important… more
Date: January 1, 1991
Creator: Calo, J. M.; Zhang, L. H.; Rachel, W. G. & Lilly, W. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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T,b, and new particle searches at p p colliders

Description: Experiments at the p{bar p} colliders at CERN and FNAL have an active program of heavy flavor physics. Recently, CDF at FNAL and UA1 at CERN have measured rare decays of the {Beta}{sup 0} {minus} {bar {Beta}}{sup 0} mixing. CDF has signals for {Beta}{sup {plus minus}} {yields} J/{psi}K{sup {plus minus}} and {Beta}{sup 0} {yields} J/{psi}K{sup *0}. Both CDF and UA1 have set limits on the branching ratio of {Beta}{sup 0} {yields} {mu}{sup +}{mu}{sup {minus}} and have measured {Beta}{sup 0} {minus… more
Date: August 1, 1991
Creator: Crane, D.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Excited state absorption measurements of Sm sup 2+ in CaF sub 2 , SrF sub 2 , and SrCl sub 2

Description: We measured the pump-probe spectrum of the Sm{sup 2+} ion in three materials: CaF{sub 2}, SrF{sub 2}, and SrCl{sub 2}. The onset of the observed prominent excited-state absorption band is consistent with an electrostatic model for impurity levels in a solid-state material. 15 refs., 4 figs., 1 tab.
Date: April 1, 1991
Creator: Lawson, J. K.; Lee, H. W. H.; Payne, S. A. (Lawrence Livermore National Lab., CA (United States)) & Boatner, L. A. (Oak Ridge National Lab., TN (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Heavy flavor physics at hadron colliders

Description: 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.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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An sup 15 N NMR method for the characterization of organic sulfur in coal and coal products via iminosulfurane formation

Description: The indirect of organic sulfur by {sup 15}N NMR spectroscopy in the solid state is feasible by facile reactions providing the iminosulfurane structures. Unfortunately, nitrogen chemical shifts appear to be insufficiently sensitive to the nature of the sulfur substituent to be useful for structural studies. Further work is underway to determine the {sup 15}N chemical shifts of iminosulfuranes formed from dibenzothiophene, 4-4{prime}-dimethoxydiphenyl sulfide, and a sulfur-containing, methylated … more
Date: September 1, 1991
Creator: Franz, J. A.; Lamb, C. N. & Linehan, J. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Dynamic-angle spinning and double rotation of quadrupolar nuclei

Description: Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-{1/2} nuclei like carbon-13 … more
Date: July 1, 1991
Creator: Mueller, K.T. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Chemistry)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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MIIT: International in-situ testing of simulated HLW forms - performance of SRS simulated waste glass after 6 mos. , 1 yr. , 2 yrs. and 5 yrs. of burial at WIPP

Description: The first field test, involving burial of simulated high-level waste (HLW) forms and package components, to be conducted in the United States, was begun in July of 1986. This program, called the Materials Interface Interactions Test or MIIT, comprises the largest cooperative field-testing venture in the international waste management community. Included in the study are over 900 waste form samples comprising 15 different systems supplied by 7 countries. Also included are about 300 potential can… more
Date: January 1, 1991
Creator: Wicks, G.G. (Westinghouse Savannah River Co., Aiken, SC (United States)); Lodding, A.R. (Chalmers Univ. of Technology, Goeteborg (Sweden)); Macedo, P.B. (Catholic Univ. of America, Washington, DC (United States)) & Clark, D.E. (Florida Univ., Gainesville, FL (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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VUV production from a ferrite-driven flash-pumped system

Description: The relative spectral emission as a function of wavelength in the 1200--2900 {Angstrom} region is measured for a vacuum UV flash device whose discharge is initiated by a high resistance formed-ferrite rod. The device is studied because of its usefulness in the optical pumping of large volume laser systems.
Date: January 1, 1991
Creator: Sze, R.C. (Los Alamos National Lab., NM (United States)) & Sentis, M. (Institut de Mecanique des Fluides, 13 - Marseille (France))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Particle identification at an asymmetric B Factory

Description: Particle identification systems are an important component of any detector at a high-luminosity, asymmetric B Factory. In particular, excellent hadron identification is required to probe CP violation in B{sup 0} decays to CP eigenstates. The particle identification systems discussed below also provide help in separating leptons from hadrons at low momenta. We begin this chapter with a discussion of the physics motivation for providing particle identification, the inherent limitations due to int… more
Date: September 1, 1991
Creator: Coyle, P.; Eigen, G.; Hitlin, D.; Oddone, P.; Ratcliff, B.; Roe, N. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Review of CERN heavy-ion physics

Description: Results from the heavy-ion experiments at the CERN SPS are reviewed in the context of possible formation and identification of a quark-gluon plasma (QGP).
Date: November 1, 1991
Creator: Odyniec, G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Plutonium isotopic analysis system for plutonium samples enriched in sup 238 Pu in EP 60/61 and fuel-clad containers

Description: This two-part manual describes and provides instructions for installing software for Lawrence Livermore National Laboratory's Pu-238 isotopic analysis system built for Westinghouse Hanford's Radioisotope Power Systems Facility. Part 1 contains descriptions of all the subroutines found in the main software program, WHC.ASY238. Also provided in this part are general instructions for modifying a subroutine and specific directions for relinking the WHC.ASY238 program, as well as information on the … more
Date: July 1, 1991
Creator: Ruhter, W. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of Chemical Additives on the Synthesis of Ethanol

Description: The objective of this research is to elucidate the role of various chemical additives on ethanol synthesis over Rh- and Ni-based catalysts. Chemical additives used for this study will include S, P, Ag, Cu, Mn, and Na which have different electronegativities. The effect of additives on the surface state of the catalysts, heat of adsorption of reactant molecules, reaction intermediates, reaction pathways, reaction kinetics, and product distributions is/will be investigated by a series of experime… more
Date: September 20, 1991
Creator: Chuang, S. S. C. & Balakos, M. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Rare K sup + decays in flight: Latest results and future plans

Description: E777 at the Brookhaven AGS has published a final branching ratio limit for the lepton family violating decay K{sup +} {yields} {pi}{sup +}{mu}{sup +}e{sup {minus}} of 2.1 {times} 10{sup {minus}10} (90% C.L.). New results based on approximately 500 events of the G.I. M. suppressed decay K{sup +} {yields} {pi}{sup +}e{sup +}e{sup {minus}} have yielded a branching ratio of (2.75 {plus minus} 0.23 {plus minus} 0.13) {times} 10{sup {minus}7} assuming a vector interaction with, a form factor = 0.105 … more
Date: January 1, 1991
Creator: Alliegro, C.; Zeller, M. E. (Yale Univ., New Haven, CT (United States)); Campagnari, C. (Chicago Univ., IL (United States)); Chaloupka, V.; Lubatti, H. J.; Zhao, T. (Washington Univ., Seattle, WA (United States)) et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The dijet mass and angular distributions at CDF

Description: The dijet mass and the jijet angular distribution, as measured in the CDF detector at the Fermilab Tevatron Collider, are compared to leading order (LO) and next-to-leading (NLO) order QCD calculations. 5 refs., 1 fig., 1 tab.
Date: September 1, 1991
Creator: Flaugher, B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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B-physics at CDF and prospects for the next run

Description: Current CDF b-physics results are presented. The analysis is based on data corresponding to an integrated luminosity of 4.4 pb{sup {minus}1} recorded with the CDF detector in 88--89 at the Fermilab Tevatron p{bar p} collider ({radical}{bar s} = 1.8 TeV). Preliminary results include the differential cross section {sub dPt}/{sup d{sigma}(b)}, some reconstructed exclusive B-decays, a limit for the rare decay B{sup 0} {yields} {mu}{sup +} {mu}{sup {minus}} and a measurement of B{bar B}-mixing param… more
Date: September 1, 1991
Creator: Wenzel, H. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Comparison of synchrotron x-ray microanalysis with electron and proton microscopy for individual particle analysis

Description: This paper is concerned with the evaluation of the use of synchrotron/radiation induced x-ray fluorescences ({mu}-SRXRF) as implemented at two existing X-ray microprobes for the analysis of individual particles. As representative environmental particulates, National Institutes of Science and Technology (NIST) K227, K309, K441 and K961 glass microspheres were analyzed using two types of X-ray micro probes: the white light microprobe at beamline X26A of the monochromatic (15 keV) X-ray microprobe… more
Date: January 1, 1991
Creator: Janssens, K. H.; van Langevelde, F.; Adams, F. C.; Vis, R. D.; Sutton, S. R.; Rivers, M. L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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An aerial radiological survey of the Central Savannah River Site, Aiken, South Carolina

Description: An aerial radiological survey was conducted over a 194-square- kilometer (75-square-mile) area encompassing the central portion of the Savannah River Site (SRS). The survey was flown during February 10--27, 1987. These radiological measurements were used as baseline data for the central area and for determining the extent of man-made radionuclide distribution. Previous SRS surveys included small portions of the area; the 1987 survey was covered during the site- wide survey conducted in 1979. Ma… more
Date: September 1, 1991
Creator: Feimster, E.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Identification of artificial gamma-emitting nuclides using a scintillator-based gamma-ray spectral logging system

Description: The standard spectral gamma ray logging system used at the Nevada Test Site (NTS) contains a large sodium iodide detector which provides high efficiency but low energy resolution. To enhance the capabilities of this system for identifying artificial gamma-emitting nuclides, I developed and implemented a simple procedure for extracting artificial components from low-resolution gamma-ray spectra. This procedures uses three bias spectra, developed by a consultant using numerical modeling, represen… more
Date: January 1, 1991
Creator: Conaway, J.G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Reactivity of young chars via energetic distribution measurements

Description: The temperature programmed desorption (TPD) has become a standard technique for investigating the physico-chemical state of adsorbed species on surfaces. In this reporting period, a new TPD-MS/TGA (mass spectrometry/thermal gravimetric analysis) system has been designed, and all the necessary components have been acquired. This new system is built around a new Cahn D-200 digital recording microbalance, which was recently purchased for this purpose. The TPD reactor essentially becomes the hangdo… more
Date: January 1, 1991
Creator: Calo, J.M.; Zhang, L.H. & Lilly, W.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Rad-hard electronics study for SSC detectors

Description: The radiation environment in a SSC detector operating at a luminosity of 10{sup 33} cm{sup {minus}2}s{sup {minus}1} will put stringent requirements on radiation hardness of the electronics. Over the expected 10 year life-time of a large detector, ionizing radiation doses of up to 20 MRad and neutron fluences of 10{sup 16} neutrons/cm{sup 2} are projected. At a luminosity of 10{sup 34} cm{sup {minus}2}s{sup {minus}1} even higher total doses are expected. the effect of this environment have been … more
Date: January 1, 1991
Creator: Ekenberg, T.; Dawson, J.; Stevens, A. & Haberichter, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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