Resource Type
Partner
UNT Libraries Government Documents Department
3,622
Dallas Municipal Archives
19
Rosenberg Library
17
UNT Libraries Special Collections
16
National WASP WWII Museum
7
Hoston History Research Center at Houston Public Library
2
Private Collection of Mario Marcel Salas
1
UNT College of Arts and Sciences
1
Collection
Office of Scientific & Technical Information Technical Reports
1,563
Congressional Research Service Reports
1,454
Technical Report Archive and Image Library
355
Government Accountability Office Reports
213
National Advisory Committee for Aeronautics Collection
192
TRAIL Microcard Collection
137
Texas State Publications
25
John F. Kennedy Memorial Collection
19
John F. Kennedy, Dallas Police Department Collection
19
Harris and Eliza Kempner
17
21 More
Serial/Series Title
Degree Department
Country
States
Decade
Month
Day
Language
Results:
1 - 24 of
3,685
next
Exploring novel silicon-containing polymers---From preceramic polymers to conducting polymers with nonlinear optical properties
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.
System:
The UNT Digital Library
Low-cost solar array project. Task I. Silicon material. Investigation of the hydrogenation of SiCl/sub 4/
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 …
Date:
October 7, 1980
Creator:
Mui, J. Y. P. & Seyferth, D.
System:
The UNT Digital Library
Some Scoping Experiments for a Space Reactor
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.
System:
The UNT Digital Library
Federal Government Health, Education, and Welfare Programs of Assistance to American Indians Residing on Federal Reservations
This report lists and describes federal health, education, and welfare programs available to Native Americans living on federal reservations.
Date:
October 7, 1969
Creator:
Langone, Stephen A.
System:
The UNT Digital Library
References to Safeguards, Physical Security, and Related Matters in the Nuclear Non-proliferation Act of 1978 (P.L. 95-242)
This report includes tables and excerpts of references to safeguards, physical security, and related matters in the Nuclear Non-proliferation Act of 1978.
Date:
July 7, 1978
Creator:
Kramer, Donna S. & Donnelly, Warren H.
System:
The UNT Digital Library
Mineral Resources of the United States Continental Shelf: Some Common Questions
This report answers some frequently asked questions regarding the mineral resources of the continental shelf of the United States
Date:
August 7, 1970
Creator:
Siehl, George H.
System:
The UNT Digital Library
Power of the President to use troops to deal with Disorders arising within the states.1967
This report is about the President powers to dispatch troops to meet three different type of problems arising in the wake of civil disturbances which interfere with the enforcement of Federal laws.
Date:
August 7, 1967
Creator:
Small, Norman J.
System:
The UNT Digital Library
New Approaches to Income Maintenance
This report discusses income maintenance programs and various proposals to reform the system.
Date:
January 7, 1970
Creator:
Humphreys, Joseph R.
System:
The UNT Digital Library
The Mexican Farm Labor Program: References, 1951-1965
This report cites the references related to the Mexican Farm Labor Program.
Date:
June 7, 1965
Creator:
Heslet, Mary R.
System:
The UNT Digital Library
An MS-DOS-based program for analyzing plutonium gamma-ray spectra
A plutonium gamma-ray analysis system that operates on MS-DOS-based computers has been developed for the International Atomic Energy Agency (IAEA) to perform in-field analysis of plutonium gamma-ray spectra for plutonium isotopics. The user interacts with the system by means of menus and screens that allow the user to select various applications and to enter information pertinent to a measurement. This information, along with the plutonium weight-percent-abundance results from the data analysis, is stored in dBASE III files. The spectral-data-analysis program, IAEAPU, determines the relative plutonium isotopic abundances from gamma-ray peaks in the 110- to 390-keV region of the spectral data. The program is compact so that it may be used on a portable, battery-operated, laptop, personal computer (PC) that uses a 3-1/2-in. floppy diskette. This is intended to be the final report on this work. We describe in detail the data-analysis methodology, the software, and the operation of the plutonium gamma-ray analysis system. 10 refs., 1 fig., 2 tabs.
Date:
September 7, 1989
Creator:
Ruhter, W. D. & Buckley, W. M.
System:
The UNT Digital Library
Geotomography applied at the Stripa Mine in Sweden
LLNL made ultrahigh-frequency (450-MHz) electromagnetic borehole-to-borehole transmissions in the Stripa Mine near Guldsmedshyttan, Sweden, in April 1979. Transmission loss measurements were made between four sets of 76-mm boreholes 30 m long, located at the end of a drift. Distances between the boreholes varied from 2 to 22 m. More than 25,000 data points were taken. A geotomograph was constructed to show the variation of attenuation between boreholes. The observed spatial variation of electromagnetic attenuation may be related to the expected stress relief created by the mine. Transmission loss measurements were also made between two converging boreholes drilled from the surface to points near the mine. Data taken at 21 MHz show a nearly uniform attenuation within this sampled region. These experiments demonstrate that geotomographic data collection/interpretation provides high-resolution images of the underground environment and can provide useful input to those charged with providing the detailed site characterizations needed for both short- and long-term monitoring of underground nuclear waste repositories.
Date:
April 7, 1980
Creator:
Okada, J.T.; Laine, E.F.; Lytle, R.J. & Daily,W.D.
System:
The UNT Digital Library
PWR Blowdown Heat Transfer Separate-Effects Program. Thermal-Hydraulic Test Facility experimental data report for test 103
Reduced instrument responses are presented for Thermal-Hydraulic Test Facility (THTF) test 103, which is part of the ORNL Pressurized-Water Reactor (PWR) Blowdown Heat Transfer Separate-Effects Program. The objective of the program is to investigate the thermal-hydraulic phenomenon governing the energy transfer and transport processes that occur during a loss-of-coolant accident in a PWR system.
Date:
March 7, 1978
Creator:
Clemons, V. D.; White, M. D.; Moore, P. A. & Hedrick, R. A.
System:
The UNT Digital Library
Atomic and molecular science with synchrotron radiation
This paper discusses the following topics: electron correlation in atoms; atomic innershell excitation and decay mechanisms; timing experiments; x-ray scattering; properties of ionized species; electronic properties of actinide atoms; total photon-interaction cross sections; and molecular physics. 66 refs. (LSP)
Date:
November 7, 1989
Creator:
unknown
System:
The UNT Digital Library
A miniature inexpensive, oxygen sensing element
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 materials' compatibility with Pt electrodes. A systematic approach was taken to develop all sensor components which led to several design modifications. Prototype sensors were constructed and exhaustively tested. It is concluded that development of Nerst-type oxygen sensors based on Bi{sub 2}O{sub 3} will require much further effort and application of specialized technologies. However, during the course of this 3-year program much progress was reported in the literature on amperometric-type oxygen sensors, and a minor effort was devoted here to this type of sensor based on Bi{sub 2}O{sub 3}. These studies were made on Bi{sub 2}O{sub 3}-based ceramic samples in a multilayer-capacitor-type geometry and amperometric-type oxygen sensing was demonstrated at very low temperatures ({approximately} 160{degree}C). A central advantage here is that these types of sensors can be mass-produced very inexpensively ({approximately} 20--50 cents …
Date:
October 7, 1991
Creator:
Arenz, R. W.
System:
The UNT Digital Library
Acceleration using total internal reflection
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.
System:
The UNT Digital Library
Evaluation of macroreticular anion exchange resin - RTA-893-R
The macroreticular anion exchange resin, Amberlite IRA-900-OH, and an experimental resin from Ionac Chemical Company were irradiated by a /sup 60/Co source to doses of 5 x 10/sup 7/ rad and 10/sup 8/ rad. These doses approximate or exceed the dose encountered by the deionizer resins in 100-Area service. The loss in exchange capacity and the volume changes of Amberlite IRA-900 on irradiation were similar to those found previously for Amberlite IRA-400. The Ionac experimental resin, which had a considerably lower initial exchange capacity, likewise was not stable to radiation. It is concluded that Amberlite IRA-900 offers no advantage over Amberlite IRA-400 for 100-Area purification service. Since there is little justification for further evaluation of macroreticular resin for 100-Area use, the present work completes RTA-893-R.
Date:
June 7, 1965
Creator:
Baumann, E. W.
System:
The UNT Digital Library
Specific heat loading in Nd:glass lasers
The specific thermal load parameter, chi, for xenon flashlamp-pumped Nd:glass gain media is written as a function of neodymium concentration, pump pulse duration, and energy extraction efficiency. The currently available data on radiative and nonradiative decay probabilities of several commercial Nd:glasses are used to calculate and graph specific thermal load parameter values. By factoring these results into performance scaling relationships for zig-zag and disk lasers, specific Nd:glasses can be selected for optimized laser performance.
Date:
August 7, 1985
Creator:
Krupke, W. F.
System:
The UNT Digital Library
Clean gasoline reforming with superacid catalysts
Tasks reported on this term include optimization of chlorided Pt- alumina catalysts, testing of the optimum Pt/Cl alumina catalysts, preparation and testing of zirconia superacid catalyst. (VC)
Date:
May 7, 1992
Creator:
Davis, B. H.
System:
The UNT Digital Library
SPE water electrolysis technology development for large scale hydrogen production. Progress report No. 4, June 15, 1976--September 30, 1976
Porous carbon fiber paper was selected as the cathode membrane and electrode assembly support based on over 1200 hr operational evaluation. Three potential anode supports are under test. All three appear technically satisfactory after 500 to 1200 hr operational evaluation on each. Optimization of molds and molding techniques for a foil backed ribbed carbon collector of bipolar design, including ribbed flow fields, manifolds, ports and sealing surfaces, is in process. Over 2800 hr demonstrated at 300/sup 0/F on platinum screened cell. Over 2200 hr demonstrated at 300/sup 0/F on cell with carbon cloth cathode current collector. Forty-eight hours screening tests of 56 different anode catalysts have been completed. A 500-hr life test program of 12 anode catalyst types which showed promise on the screening tests has been started. Attempts to stabilize RuO/sub x/ for use as an anode catalyst are being pursued. Low loaded cathodes on graphite substrates show performance to within 25 MV of baseline. Optimization of substrate thickness and fabrication procedures is continuing. Twenty-five low loaded anodes catalyst/substrate combinations have all shown poor performance stability with time. Continued development of the grafted TFS membrane has shown greatly improved physical characteristics and encouraging performance for samples in the 25 …
Date:
October 7, 1976
Creator:
unknown
System:
The UNT Digital Library
Application of the Argonne Advanced Acceleration Test Facility to development for conventional accelerators
The Argonne Advanced Acceleration Test Facility is designed as a powerful tool to test ideas for very high gradient acceleration schemes based on direct beam excitation of plasmas, metal structures, dielectrics, etc. The characteristic size in these systems is )approximately) 1 cm, corresponding to frequencies )approximately) 10 GHz. The question addressed here is whether the special features of this facility have application as well to the development of components for the more conventional, lower frequency, accelerators now operating or under development. It is suggested that the usefulness of the facility for the development of conventional systems could be enhanced by a provision for longer time delay between driver and witness beam pulses. 9 refs., 2 figs.
Date:
April 7, 1988
Creator:
MacLachlan, J.A.
System:
The UNT Digital Library
LOFT suppression tank spray system piping: heat exchanger BS-H-31 piping modifications
A stress analysis of the piping modification, resulting from relocation of heat exchanger BS-H-31 of the LOFT Blowdown Suppressing Tank Spray System, was performed. The piping, fittings, and supports were found to comply with the criteria of Section III of the ASME Boiler and Pressure Vessel Code, 1974.
Date:
November 7, 1977
Creator:
Blandford, R.K.
System:
The UNT Digital Library
Procedure for matching synfuel users with potential suppliers. Appendix B. Proposed and ongoing synthetic fuel production projects
To assist the Department of Energy, Office of Fuels Conversion (OFC), in implementing the synthetic fuel exemption under the Powerplant and Industrial Fuel Use Act (FUA) of 1978, Resource Consulting Group, Inc. (RCG), has developed a procedure for matching prospective users and producers of synthetic fuel. The matching procedure, which involves a hierarchical screening process, is designed to assist OFC in: locating a supplier for a firm that wishes to obtain a synthetic fuel exemption; determining whether the fuel supplier proposed by a petitioner is technically and economically capable of meeting the petitioner's needs; and assisting the Synthetic Fuels Corporation or a synthetic fuel supplier in evaluating potential markets for synthetic fuel production. A data base is provided in this appendix on proposed and ongoing synthetic fuel production projects to be used in applying the screening procedure. The data base encompasses a total of 212 projects in the seven production technologies.
Date:
August 7, 1981
Creator:
unknown
System:
The UNT Digital Library
High pressure gas metering project
The initial research and development of a system that uses high pressure helium gas to pressurize vessels over a wide range of pressurization rates, vessel volumes, and maximum test pressures are described. A method of controlling the mass flow rate in a test vessel was developed by using the pressure difference across a capillary tube. The mass flow rate is related to the pressurization rate through a real gas equation of state. The resulting mass flow equation is then used in a control algorithm. Plots of two typical pressurization tests run on a manually operated system are included.
Date:
July 7, 1980
Creator:
Tripp, L.R.
System:
The UNT Digital Library
Gaseous phase coal surface modification
In this report, we present an improved, feasible and potentially cost effective method of cleaning and beneficiating ultrafine coal. Increased mechanization of mining methods and the need towards depyritization, and demineralization have led to an increase in the quantity of coal fines generated in recent times. For example, the amount of {minus}100 mesh coal occurring in coal preparation plant feeds now typically varies from 5 to 25% of the total feed. Environmental constraints coupled with the greatly increased cost of coal have made it increasingly important to recover more of these fines. Our method chemically modifies the surface of such coals by a series of gaseous phase treatments employing Friedel-Crafts reactions. By using olefins (ethene, propene and butene) and hydrogen chloride catalyst at elevated temperature, the surface hydrophobicity of coal is enhanced. This increased hydrophobicity is manifest in surface phenomena which reflect conditions at the solid/liquid interphase (zeta potential) and those which reflect conditions at the solid/liquid/gas interphases (contact angle, wettability and floatability).
Date:
May 7, 1992
Creator:
Okoh, J.M.; Pinion, J. & Thiensatit, S.
System:
The UNT Digital Library