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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
open access

[Letter from Cassandra Broadus to Esther Livingston, January 7, 1991]

Description: Photocopy of a letter from Cassandra Broadus, to Esther Livingston, teacher at T.D. Marshall Elementary School. Broadus has gifted Livingston overhead transparencies to be used in Livingston's transportation unit curriculum. The transparencies include, Winslow Homer's Breezing Up (A Fair Wind) and other similar subjects for the elementary school children. Broadus ends the letter by suggesting a class visitation to correlate a lesson plan for the children in arts and language.
Date: January 7, 1991
Creator: Broadus, Cassandra
Item Type: Refine your search to only Letter
Partner: UNT Libraries Special Collections
open access

[Letter from Cassandra Broadus to Anne Sears, March 7 1991]

Description: Photocopy of a letter from Cassandra Broadus, North Texas Institute for Educators on the Visual Arts, to Anne Sears, teacher at T.D. Marshall Learning Center. Broadus has given Sears lesson plans from Kay Alexander's Learning to Look and Create: The SPECTRA Series. Broadus writes that the art curriculum offers numerous ideas for correlating activities with concepts and addresses interdisciplinary curriculum ideas, highlighting some important introductory lesson plans that Broadus believes will … more
Date: March 7, 1991
Creator: Broadus, Cassandra
Item Type: Refine your search to only Letter
Partner: UNT Libraries Special Collections
open access

A miniature inexpensive, oxygen sensing element

Description: An exhaustive study was conducted to determine the feasibility of Nernst-type oxygen sensors based on ceramics containing Bi{sub 2}O{sub 3}. The basic sensor design consisted of a ceramic sensing module sealed into a metal tube. The module accommodated an internal heater and thermocouple. Thermal-expansion-matched metals, adhesives, and seals were researched and developed, consistent with sequential firings during sensor assembly. Significant effort was devoted to heater design/testing and to m… more
Date: October 7, 1991
Creator: Arenz, R. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Acceleration using total internal reflection

Description: This report considers the use of a dielectric slab undergoing total internal reflection as an accelerating structure for charged particle beams. We examine the functional dependence of the electromagnetic fields above the surface of the dielectric for polarized incident waves. We present an experimental arrangement for testing the performance of the method, using apparatus under construction for the Grating Acceleration experiment at Brookhaven National Laboratory. 13 refs., 4 figs., 2 tabs.
Date: June 7, 1991
Creator: Fernow, R.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Positron lifetimes in solids from first principles calculations

Description: We present a first principles method for calculating positron lifetimes in solids, based on self-consistent calculations using the Linear Muffin-Tin Orbital method. Local density approximations are used for both electron-electron and electron-positron interactions. Results are presented for a variety of elemental metals and vacancies to demonstrate the reliability of this approach. Theoretical calculations of positron lifetimes can be used to interpret experimental data. As an examples of this,… more
Date: August 7, 1991
Creator: Sterne, P. A.; O'Brien, J. C.; Howell, R. H. & Kaiser, J. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Hydrodynamick instabilities on ICF capsules

Description: This article summarizes our current understanding of hydrodynamic instabilities as relevant to ICF. First we discuss classical, single mode Rayleigh-Taylor instability, and nonlinear effects in the evolution of a single mode. Then we discuss multimode systems, considering: (1) the onset of nonlinearity; (2) a second order mode coupling theory for weakly nonlinear effects, and (3) the fully nonlinear regime. Two stabilization mechanisms relevant to ICF are described next: gradient scale length a… more
Date: June 7, 1991
Creator: Haan, S.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Faculty Recital: 1991-10-07 - S. Bancroft (bassoon); M. K. Clardy (flute); J. Mainous (piano); D. Richtmeyer (alto saxophone)

Description: Faculty recital performed at the UNT College of Music Recital Hall.
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: October 7, 1991
Duration: 55 minutes 18 seconds
Creator: Bancroft, Sue; Clardy, Mary Karen; Mainous, Jean & Richtmeyer, Debra
Item Type: Refine your search to only Sound
Location: 33.210701 -97.150088
Partner: UNT Music Library
open access

[Letter from Jack Davis to Thomas F. Beech, February 7, 1991]

Description: Photocopy of a letter from Jack Davis, co-director of North Texas Institute for Educators on the Visual Arts, to Thomas F. Beech, executive vice president of the Anne Burnett and Charles D. Tandy Foundation. The letter is in regards to previous correspondence between Davis and Beech, where Beech said to submit progress of the institute at the beginning of the year for re-consideration of grant support from the foundation. The letter goes into detailed length of the success of the first year of … more
Date: February 7, 1991
Creator: Davis, Donald Jack
Item Type: Refine your search to only Letter
Partner: UNT Libraries Special Collections
open access

Effective theories and thresholds in particle physics

Description: The role of effective theories in probing a more fundamental underlying theory and in indicating new physics thresholds is discussed, with examples from the standard model and more speculative applications to superstring theory. 38 refs.
Date: June 7, 1991
Creator: Gaillard, M. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The Savannah River Site's Groundwater Monitoring Program, second quarter 1990

Description: The Environmental Protection Department/Environmental Monitoring Section (EPD/EMS) administers the Savannah River Site's (SRS) Groundwater Monitoring Program. During second quarter 1990 (April through June) EPD/EMS conducted routine sampling of monitoring wells and drinking water locations. EPD/EMS established two sets of flagging criteria in 1986 to assist in the management of sample results. The flagging criteria aid personnel in sample scheduling, interpretation of data, and trend identifica… more
Date: February 7, 1991
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Relativistic shock waves and the excitation of plerions

Description: The shock termination of a relativistic magnetohydrodynamic wind from a pulsar is the most interesting and viable model for the excitation of the synchrotron sources observed in plerionic supernova remnants. We have studied the structure of relativistic magnetosonic shock waves in plasmas composed purely of electrons and positrons, as well as those whose composition includes heavy ions as a minority constituent by number. We find that relativistic shocks in symmetric pair plasmas create fully t… more
Date: January 7, 1991
Creator: Arons, J. (California Univ., Berkeley, CA (USA)); Gallant, Y.A. (California Univ., Berkeley, CA (USA). Dept. of Physics); Hoshino, Masahiro; Max, C.E. (California Univ., Livermore, CA (USA). Inst. of Geophysics and Planetary Physics) & Langdon, A.B. (Lawrence Livermore National Lab., CA (USA))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Hydrogen-like recombination x-ray laser experiments using a 20 picosecond laser pulse at the Nova facility

Description: Hydrogen-like recombination X-ray lasers are currently under investigation as an alternative candidate to collisional pumped soft X-ray amplifiers. Efforts are being concentrated on the n = 3 to n = 2 transitions in H-like Mg and NaF. 5 refs., 1 fig.
Date: January 7, 1991
Creator: Shephard, R.; Fields, D.; DaSilva, L.; Keane, C.; MacGowen, B.; Matthews, D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
captions transcript

[News Clip: Murder suspect]

Description: Video footage from the KXAS-TV television station in Fort Worth, Texas, covering a news story.
Date: March 7, 1991, 10:00 p.m.
Duration: 1 minute 28 seconds
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Item Type: Refine your search to only Video
Partner: UNT Libraries Special Collections
captions transcript

[News Clip: Ft Hood]

Description: Video footage from the KXAS-TV television station in Fort Worth, Texas, covering a news story.
Date: March 7, 1991, 10:00 p.m.
Duration: 1 minute 49 seconds
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Item Type: Refine your search to only Video
Partner: UNT Libraries Special Collections
open access

Short wavelength nickel-like x-ray laser development

Description: Ni-like x-ray lasers have been produced at wavelengths near to, and below the carbon K edge (43.76-{Angstrom}). Recent work has concentrated on the development of the Ni-like Ta amplifier at 44.83-{Angstrom}. Amplification occurs in a laser produced plasma created by irradiating a thin foil of Ta with two beams of the Nova laser. Up to 8 gainlengths have been demonstrated so far, with a gain coefficient of 3.2 cm{sup {minus}1} and a gain duration of 250 psec. The wavelength of 44.83-{Angstrom} … more
Date: January 7, 1991
Creator: MacGowan, B. J.; Da Silva, L. B.; Fields, D. J.; Fry, A. R.; Keane, C. J.; Koch, J. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Particle physics and superstrings

Description: Implications of recent precision measurements of the standard model gauge coupling constants are discussed in the context of superstring theory. 40 refs.
Date: June 7, 1991
Creator: Gaillard, M.K. (California Univ., Berkeley, CA (United States). Dept. of Physics Lawrence Berkeley Lab., CA (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Even- and odd-parity finite-element transport solutions in the thick diffusion limit

Description: We analyze the behavior of odd-parity continuous finite-element methods (CFEMs) for problems that contain diffusive regions. We find that each of these method produces a solution that, to leading order inside diffusive regions, satisfies a discretization of the diffusion equation. We find further that these leading-order solutions satisfy boundary conditions that can lead to large errors in the interior solution. We recognize, however, that we can combine an odd-purity CFEM solution and an even… more
Date: January 7, 1991
Creator: Adams, M.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Simulation of longitudinal coupled-bunch instabilities

Description: The purpose of this note is to document some work done as part of the effort directed at designing and simulating a bunch-by-bunch feedback system to control longitudinal coupled bunch instabilities in the B-factory. In particular, I discuss the ring model used in the simulation program developed to study this feedback system. Basically the simulation is a simple tracking program in which the rf drive voltage, the wakefields due to all the bunches, the synchrotron radiation losses, and the kick… more
Date: February 7, 1991
Creator: Thompson, K.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Petroleum marketing monthly, November 1991. [Contains glossary]

Description: The Petroleum Marketing Monthly is designed to give information and statistical data about a variety of crude oils and refined petroleum products. The publication provides statistics on crude oil costs and refined petroleum products sales for use by industry, government, private sector analysts, educational institutions, and consumers. Data on crude oil include the domestic first purchase price, the f.o.b. and landed cost of imported crude oil, and the refiners' acquisition cost of crude oil. S… more
Date: November 7, 1991
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Extending the alias Monte Carlo sampling method to general distributions

Description: The alias method is a Monte Carlo sampling technique that offers significant advantages over more traditional methods. It equals the accuracy of table lookup and the speed of equal probable bins. The original formulation of this method sampled from discrete distributions and was easily extended to histogram distributions. We have extended the method further to applications more germane to Monte Carlo particle transport codes: continuous distributions. This paper presents the alias method as ori… more
Date: January 7, 1991
Creator: Edwards, A. L.; Rathkopf, J. A. & Smidt, R. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Magnetospheric structure of rotation powered pulsars

Description: I survey recent theoretical work on the structure of the magnetospheres of rotation powered pulsars, within the observational constraints set by their observed spindown, their ability to power synchrotron nebulae and their ability to produce beamed collective radio emission, while putting only a small fraction of their energy into incoherent X- and gamma radiation. I find no single theory has yet given a consistent description of the magnetosphere, but I conclude that models based on a dense ou… more
Date: January 7, 1991
Creator: Arons, J. (California Univ., Berkeley, CA (USA) California Univ., Livermore, CA (USA). Inst. of Geophysics and Planetary Physics)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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