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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(diphenylsilyldiacetylene) via dehydrogenation, was reinvestigated. Spectroscopic studies showed that the polymer had a structure of polyacetylene type not diacetylene. Diphenyldiethynylgermane and a series of diorganodiethynylsilances were synthesized. These could be polymerized in the presence of MoCl{sub 5} or WCl{sub 6} to afford a soluble, violet material with Mw as high as 108,000. 100 refs., 56 figs., 16 tabs.
Date: October 7, 1991
Creator: Pang, Yi.
Partner: UNT Libraries Government Documents Department

Ensemble: 2017-11-07 – UNT University Singers [Stage Perspective]

Description: Choir concert performed at the UNT College of Music Winspear Hall. This video is shot from the choir's perspective, showing the conductor.
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: November 7, 2017
Duration: 7 minutes 28 seconds
Creator: University of North Texas. University Singers
Partner: UNT Music Library
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Low-cost solar array project. Task I. Silicon material. Investigation of the hydrogenation of SiCl/sub 4/

Description: Reaction kinetic measurements on the hydrochlorination of SiCl/sub 4/ and m.g. silicon metal were last reported as a function of reaction temperature, reactor pressure, H/sub 2//SiCl/sub 4/ ratio and silicon metal particle size distribution, 3 SiCl/sub 4/ + 2 H/sub 2/ + Si reversible 4 SiHCl/sub 3/. The effect of impurities in the m.g. silicon metal on the rate of this reaction has been investigated in this quarter. The m.g. silicon was replaced with high purity, electronic grade silicon metal in the hydrochlorination reaction. With electronic grade Si, the reaction rate was found to be about one order of magnitude slower than those obtained with m.g. silicon metal. These metallic impurities in the m.g. silicon appear to have a catalytic effect. Addition of 5 wt% cuprous chloride to the electronic grade Si mass bed increased the reaction rate to the same level as those obtained with m.g. silicon with 5% CuCl added. The effect of prolonged reaction time on the hydrochlorination reaction was studied. The plan is to run the reaction for long periods of time with the objective of studying the life of the Si mass bed. No significant change in the reaction rate was observed after about 80 hours of reaction.
Date: October 7, 1980
Creator: Mui, J. Y. P. & Seyferth, D.
Partner: UNT Libraries Government Documents Department
open access

Some Scoping Experiments for a Space Reactor

Description: Some scoping experiments were performed to evaluate fuel performance in a lithium heat pipe reactor operating at a nominal 1500K heat pipe temperature. Fuel-coolant and fuel-coolant-clad relationships showed that once a failed heat pipe occurs temperatures can rise high enough so that large concentrations of uranium can be transported by the vapor phase. Upon condensation this uranium would be capable of penetrating heat pipes adjacent to the failed pipe. The potential for propagation of failure exists with UO/sub 2/ and a lithium heat pipe. Changing the composition of the metal of the heat pipe would have only a second order effect on the kinetics of the failure mechanism. Uranium carbide and nitride were considered as potential fuels which are nonreactive in a lithium environment. At high temperatures the nitride would be favored because of its better compatibility with potential cladding materials. Compositions of UN with small additions of YN appear to offer very attractive properties for a compact high temperature high power density reactor.
Date: July 7, 1983
Creator: Alexander, C. A. & Ogden, J. S.
Partner: UNT Libraries Government Documents Department
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[News Script: Tower]

Description: Script from the WBAP-TV/NBC station in Fort Worth, Texas relating a news story.
Date: March 7, 1969
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections
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[News Script: Death]

Description: Script from the WBAP-TV/NBC station in Fort Worth, Texas relating a news story.
Date: October 7, 1968
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections
open access

[Letter from Marvin E. Edwards to Bill McCarter, February 7, 1992]

Description: Photocopy of a letter from Marvin E. Edwards, General Superintendent, Dallas ISD, to Bill McCarter, co-director for North Texas Institute for Educators on the Visual Arts. Thanking McCarter for his letter of January 10, 1992 requesting the attendance of Janice Wiggins, Visual Arts Specialist for the DISD at the National Art Education Association Conference, which Edwards is pleased to have her participate in the DBAE report. Edwards also is in support of the discipline-based approach to teaching of the art as it not only encourages studio art training but reinforces other goals like improved reading, interdisciplinary studies and high lever activities. Edwards is pleased with the program and what opportunities it offers their students.
Date: February 7, 1992
Creator: Edwards, Marvin E.
Partner: UNT Libraries Special Collections
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[RE: "Achieving National Education Reform: Arts Education as Catalyst," January 7, 1993]

Description: Photocopy of a letter from Vicki Rosenberg, program officer of the Getty Center, to the Regional and Californian Institute Exhibition Staff. In regards to "Achieving National Education Reform: Art Education as Catalyst" conference being held at San Francisco Hilton and Towers, February 3, 1993. The letter holds information about travel arrangements needed to be made before January 20th, hotel reservations and notification that the Getty center will cover the cost of lodging, incidental expenses that the center will reimburse related to the attendance at the conference, including meals and transportation from airport, exhibition staff duties being members of the regional institute, and conference registration. Enclosed with the invitation, are a schedule of the conference for the exhibit staff and an agenda list.
Date: January 7, 1993
Creator: Rosenberg, Vicki
Partner: UNT Libraries Special Collections
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[Letter from Nancy Reynolds to Nancy Ruff, May 7, 1993]

Description: Photocopy of a letter from Nancy Reynolds, project coordinator of North Texas Institute for Educators on the Visual Arts, to Nancy Ruff, Hurst-Euless-Bedford ISD. In regards to a letter that Bill McCarter and Jack Davis wrote to Russ Chapman, Principal of Lakewood Elementary School, to congratulate Chapman on being selected by the Getty Institute to attend a National Administrators Focus Group Conference. Reynolds informs Ruff that Chapman will give presentations on two different days about the importance of arts in education, June 8th and June 14th.
Date: May 7, 1993
Creator: Reynolds, Nancy
Partner: UNT Libraries Special Collections
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