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The Black Paintings (Dawn)

Description: Multiple wall size paintings of gray, peach and black striated vertical lines rendered on top of night or city landscape.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: 1986
Creator: Patkin, Izhar
Partner: UNT College of Visual Arts + Design

Endurance tests of a 22-inch-diameter pulse-jet engine with a neoprene-coated valve grid

Description: Report discussing the results of testing to determine the operating life of a 22-inch-diameter pulse-jet engine equipped with a neoprene-coated valve grid. The valve grid was found to extend the operating life and only reduced the performance slightly.
Date: October 3, 1945
Creator: Manganiello, Eugene J.; Valerino, Michael F. & Breisch, John H.
Partner: UNT Libraries Government Documents Department

Sensitivity tests on leaded glove material, EMRTC Report FR-95-15: Final test report

Description: Small-scale safety and characterization tests were performed on stored radioactive wastes. The materials tested were formed when leaded dry box gloves were exposed to nitric acid. The nitration products exhibited thermal and impact sensitivity which could lead to ignition of explosion. Water was used to separate the nitrated glove material into several fractions; only the insoluble fraction exhibited significant sensitivity to impact. Both the separated and mixed materials were thermally unstable. Self-heating occurred at about 80C or lower, depending on the quantity of material tested. The drop weight impact sensitivity of one sample was greater than that of trinitrotoluene. The electrostatic spark discharge sensitivity of the nitration products was measured to be less than for typical secondary explosives. No sensitivity to friction was measured. These results indicate that the nitrated gloves can probably be handled without extreme risk of ignition. Washing the nitrated materials was found to desensitize the materials, indicating that water could be used as a solvent when storing the materials.
Date: June 1, 1995
Creator: Olson, D.; Davis, L. & Block-Bolten, A.
Partner: UNT Libraries Government Documents Department

Prompt non-tire rubber recycling : final report for phases 1 and 2.

Description: This report summarizes an assessment conducted by Environmental Technologies Alternatives, Inc., under a subcontract to Argonne National Laboratory. The project was conducted in two phases. An assessment of alternative technologies for recycling of prompt non-tire rubber was conducted in the first phase, and an experimental program focusing on a new technology called the catalytic Regeneration Process offered the greatest opportunity for recovery of high-value recyclable rubber material. An experimental and large-scale test program was undertaken to further delineate the economic potential as an essential step leading to commercial deployment and to determine the course of continued development of the technology by the private sector. The experimental program defined process-operating conditions for the technology and verified the degree of devulcanisation achievable for two rubber compounds: ethylene-propylene-nonconjugated-diene monomer (EPDM) and neoprene. To determine product acceptance, samples of devulcanized EPDM and neoprene were prepared and used in factory trials for the production of automotive moldings (EPDM) and fiber-filled belting (neoprene). The factory trials indicated that the physical properties of the products were acceptable in both cases. The appearance of molded and calendared surface finishes was acceptable, while that of extruded finishes was unsatisfactory. The fiber-filled neoprene belting application offers the greatest economic potential. Process costs were estimated at $0.34/lb for neoprene waste rubber relative to a value of $0.57/lb. The results of the experimental program led to the decision to continue development of this technology is being planned, subject to the availability of about $3 million in financing from private-sector investors. The ability to recycle non-tire rubber scrap could conserve as much as 90,000 Btu/lb, thus yielding an estimated energy savings potential of about 0.25 quad/yr.
Date: June 25, 1999
Creator: Smith, F. G. & Daniels, E. J.
Partner: UNT Libraries Government Documents Department

Reducing System Artifacts in Hyperspectral Image Data Analysis with the Use of Estimates of the Error Covariance in the Data

Description: Hyperspectral Fourier transform infrared images have been obtained from a neoprene sample aged in air at elevated temperatures. The massive amount of spectra available from this heterogeneous sample provides the opportunity to perform quantitative analysis of the spectral data without the need for calibration standards. Multivariate curve resolution (MCR) methods with non-negativity constraints applied to the iterative alternating least squares analysis of the spectral data has been shown to achieve the goal of quantitative image analysis without the use of standards. However, the pure-component spectra and the relative concentration maps were heavily contaminated by the presence of system artifacts in the spectral data. We have demonstrated that the detrimental effects of these artifacts can be minimized by adding an estimate of the error covariance structure of the spectral image data to the MCR algorithm. The estimate is added by augmenting the concentration and pure-component spectra matrices with scores and eigenvectors obtained from the mean-centered repeat image differences of the sample. The implementation of augmentation is accomplished by employing efficient equality constraints on the MCR analysis. Augmentation with the scores from the repeat images is found to primarily improve the pure-component spectral estimates while augmentation with the corresponding eigenvectors primarily improves the concentration maps. Augmentation with both scores and eigenvectors yielded the best result by generating less noisy pure-component spectral estimates and relative concentration maps that were largely free from a striping artifact that is present due to system errors in the FT-IR images. The MCR methods presented are general and can also be applied productively to non-image spectral data.
Date: January 1, 2002
Partner: UNT Libraries Government Documents Department

General solutions for the oxidation kinetics of polymers

Description: The simplest general kinetic schemes applicable to the oxidation of polymers are presented, discussed and analyzed in terms of the underlying kinetic assumptions. For the classic basic autoxidation scheme (BAS), which involves three bimolecular termination steps and is applicable mainly to unstabilized polymers, typical assumptions used singly or in groups include (1) long kinetic chain length, (2) a specific ratio of the termination rate constants and (3) insensitivity to the oxygen concentration (e.g., domination by a single termination step). Steady-state solutions for the rate of oxidation are given in terms of one, two, three, or four parameters, corresponding respectively to three, two, one, or zero kinetic assumptions. The recently derived four-parameter solution predicts conditions yielding unusual dependencies of the oxidation rate on oxygen concentration and on initiation rate, as well as conditions leading to some unusual diffusion-limited oxidation profile shapes. For stabilized polymers, unimolecular termination schemes are typically more appropriate than bimolecular. Kinetics incorporating unimolecular termination reactions are shown to result in very simple oxidation expressions which have been experimentally verified for both radiation-initiated oxidation of an EPDM and thermoxidative degradation of nitrile and chloroprene elastomers.
Date: August 1, 1996
Creator: Gillen, K.T.; Clough, R.L. & Wise, J.
Partner: UNT Libraries Government Documents Department

Compatibility of refrigerants and lubricants with motor materials under retrofit conditions. Final report, Volume 1

Description: Compatibility tests were conducted on motor materials to determine if exposure to the original refrigerant/mineral oil would affect compatibility of the motor materials after retrofit to the alternative refrigerant/lubricant. The motor materials were exposed at elevated temperature to the original refrigerant and mineral oil for 500 hours, followed by exposure to the alternative refrigerant and lubricant for 500 hours. Measurements were also taken after 168 and 336 hours. As a control, some samples were exposed to the original refrigerant/mineral oil for a total of 1000 hours. The original refrigerants and the Alternatives tested for retrofit were as follows: Most motor materials exposed to the alternative refrigerant and lubricant (after an initial exposure to the original refrigerant and mineral oil) were compatible with the alternative refrigerant and lubricant. The only concern was delamination and blistering of the sheet insulation containing Nomex, especially after removal of absorbed refrigerant. This was attributed to solution of the adhesive and not to the Nomex itself. Embrittlement of the polyethylene terephthalate (PET) found in Mylar and Melinex sheet and sleeving insulations was initially observed, but subsequent tests under dry conditions showed that embrittlement of the PET materials was caused by moisture present during the exposure. Compatibility tests of elastomers with R-245ca, retrofitted from R-11 and R-123, showed that the nitrile was compatible with both R-11 and R-245ca, but not with R-123. The neoprene was unsatisfactory because of shrinkage in the R-245ca.
Date: October 1, 1996
Creator: Doerr, R.G. & Waite, T.D.
Partner: UNT Libraries Government Documents Department

[Recycle of contaminated scrap metal]: Task 1.3.2, Bulk solids feed system. Topical report, October 1993-- January 1996

Description: A critical requirement in DOE`s efforts to recycle, reuse, and dispose of materials from its decontamination and decommissioning activities is the design of a robust system to process a wide variety of bulk solid feeds. The capability to process bulk solids will increase the range of materials and broaden the application of Catalytic Extraction Processing (CEP). The term bulk solids refers to materials that are more economically fed into the top of a molten metal bath than by submerged injection through a tuyere. Molten Metal Technology, Inc. (MMT) has characterized CEP`s ability to process bulk solid feed materials and has achieved significant growth in the size of bulk solid particles compatible with Catalytic Extraction Processing. Parametric experimental studies using various feed materials representative of the components of various DOE waste streams have validated design models which establish the reactor operating range as a function of feed material, mass flow rate, and particle size. MMT is investigating the use of a slurry system for bulk solid addition as it is the most efficient means for injecting soils, sludges, and similar physical forms into a catalytic processing unit. MMT is continuing to evaluate condensed phase product removal systems and alternative energy addition sources to enhance the operating efficiency of bulk solids CEP units. A condensed phase product removal system capable of on-demand product removal has been successfully demonstrated. MMT is also investigating the use of a plasma arc torch to provide supplemental heating during bulk solids processing. This comprehensive approach to bulk solids processing is expected to further improve overall process efficiency prior to the deployment of CEP for the recycle, reuse, and disposal of materials from DOE decontamination and decommissioning Activities.
Date: July 1, 1996
Partner: UNT Libraries Government Documents Department


Description: A bibliography of approximates 440 references is presented which is arranged into sections dealing with polyacrylates, polyamides, polybutadienes and copolymers, polycarbonates, cellulosics, epoxy resins, polyesters, polyethers, polyethylenes, natural rubber, neoprene, phenolics, polypropylene, rubbers, silicones, polystyrenes, urethanes, polyvinylidenes, polyvinyls, and miscellaneous systems. Reviews, data compilations, books, and references dealing with dynamic mechanical properties are also listed. (D.L.C.)
Date: July 1, 1963
Partner: UNT Libraries Government Documents Department

Correlation of Chemical and Mechanical Property Changes During Oxidative Degradation of Neoprene

Description: The thermal degradation of a commercial, stabilized, unfilled neoprene (chloroprene) rubber was investigated at temperatures up to 140 C. The degradation of this material is dominated by oxidation rather than dehydrochlorination. Important heterogeneous oxidation effects were observed at the various temperatures investigated using infrared micro-spectroscopy and modulus profiling. Intensive degradation-related spectral changes in the IR occurred in the conjugated carbonyl and hydroxyl regions. Quantitative analysis revealed some differences in the development of the IR oxidation profiles, particularly towards the sample surface. These chemical degradation profiles were compared with modulus profiles (mechanical properties). It is concluded that the profile development is fundamentally described by a diffusion-limited autoxidation mechanism. Oxygen consumption measurements showed that the oxidation rates display non-Arrhenius behavior (curvature) at low temperatures. The current results, when compared to those of a previously studied, clay-filled commercial neoprene formulation, indicate that the clay filler acts as an antioxidant, but only at low temperatures.
Date: July 1, 1999
Creator: Celina, M.; Wise, J.; Ottesen, D.K.; Gillen, K.T. & Clough, R.L.
Partner: UNT Libraries Government Documents Department

Microbial Gas Generation Under Expected Waste Isolation Pilot Plant Repository Conditions: Final Report

Description: Gas generation from the microbial degradation of the organic constituents of transuranic (TRU) waste under conditions expected in the Waste Isolation Pilot Plant (WIPP) was investigated. The biodegradation of mixed cellulosic materials and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, hypalon, leaded hypalon, and neoprene) was examined. We evaluated the effects of environmental variables such as initial atmosphere (air or nitrogen), water content (humid ({approx}70% relative humidity, RH) and brine inundated), and nutrient amendments (nitogen phosphate, yeast extract, and excess nitrate) on microbial gas generation. Total gas production was determined by pressure measurement and carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) were analyzed by gas chromatography; cellulose degradation products in solution were analyzed by high-performance liquid chromatography. Microbial populations in the samples were determined by direct microscopy and molecular analysis. The results of this work are summarized.
Date: July 1, 2011
Creator: Gillow, J. B. & Francis, A.
Partner: UNT Libraries Government Documents Department

Nuclear Energy Plant Optimization (NEPO) final report on aging and condition monitoring of low-voltage cable materials.

Description: This report summarizes results generated on a 5-year cable-aging program that constituted part of the Nuclear Energy Plant Optimization (NEPO) program, an effort cosponsored by the U. S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI). The NEPO cable-aging effort concentrated on two important issues involving the development of better lifetime prediction methods as well as the development and testing of novel cable condition-monitoring (CM) techniques. To address improved life prediction methods, we first describe the use of time-temperature superposition principles, indicating how this approach improves the testing of the Arrhenius model by utilizing all of the experimentally generated data instead of a few selected and processed data points. Although reasonable superposition is often found, we show several cases where non-superposition is evident, a situation that violates the constant acceleration assumption normally used in accelerated aging studies. Long-term aging results over extended temperature ranges allow us to show that curvature in Arrhenius plots for elongation is a common occurrence. In all cases the curvature results in a lowering of the Arrhenius activation energy at lower temperatures implying that typical extrapolation of high temperature results over-estimates material lifetimes. The long-term results also allow us to test the significance of extrapolating through the crystalline melting point of semi-crystalline materials. By utilizing ultrasensitive oxygen consumption (UOC) measurements, we show that it is possible to probe the low temperature extrapolation region normally inaccessible to conventional accelerated aging studies. This allows the quantitative testing of the often-used Arrhenius extrapolation assumption. Such testing indicates that many materials again show evidence of ''downward'' curvature (E{sub a} values drop as the aging temperature is lowered) consistent with the limited elongation results and many literature results. It is also shown how the UOC approach allows the probing of temperatures that cross through the crystalline melting point ...
Date: November 1, 2005
Creator: Assink, Roger Alan; Gillen, Kenneth Todd & Bernstein, Robert
Partner: UNT Libraries Government Documents Department

OTEC elastomer cold water pipe preliminary design study. Final report

Description: Goodyear Aerospace Corporation has analyzed the requirements for a 30 ft dia 3280 ft long Cold Water Pipe for an Ocean Thermal Energy Conversion (OTEC) 10/40 MW Pilot Plant. A preliminary design using elastomer covered, flexible steel cable, conveyor belt material is presented. The design concept was predicated on employing state-of-the-art production techniques and having the capability for expansion to a commercial power plant size without further development. The report provides a data base for a compliant elastomer pipe and includes material properties, design details, cost, fabrication and schedule information. Both cable and fabric reinforced constructions are addressed and a comparison of various concepts for assembly of the pipe sections has been made.
Date: November 13, 1979
Creator: Mehring, R D
Partner: UNT Libraries Government Documents Department

Mechanical properties of cables exposed to simultaneous thermal and radiation aging

Description: Sandia National Laboratories is conducting long-term aging research on representative samples of nuclear power plant Class 1E cables. The objectives of this program are to determine the suitability of these cables for extended life (beyond the 40-year design basis) and to assess various cable condition monitoring (CM) techniques for predicting remaining cable life. This paper provides the results of mechanical measurements that were performed on cable specimens cross-linked polyethylene neoprene jackets: chlorinated polyethylene jackets, fiberglass braid jackets, and chlorosulfonated polyethylene jackets aged at relatively mild, simultaneous thermal and radiation exposure conditions for periods of up to nine months. After aging, some of the aged samples, as well as some unaged samples, were exposed to accident gamma radiation at ambient temperature. The mechanical measurements discussed in this paper include tensile strength, ultimate elongation, and compressive modulus. 10 refs., 22 figs., 2 tabs.
Date: January 1, 1990
Creator: Jacobus, M.J. (Sandia National Labs., Albuquerque, NM (USA)) & Fuehrer, G.F. (Science and Engineering Associates, Inc., Albuquerque, NM (USA))
Partner: UNT Libraries Government Documents Department

Cask systems development program seal technology

Description: General design or test performance requirements for radioactive materials (RAM) packages are specified in Title 10 of the US Code of Federal Regulations Part 71 (10 CFR 71). Seals that provide the containment system interface between the packaging body and the closure must function in both high- and low-temperature environments under dynamic and static conditions. Experiments were performed to characterize the performance of several seal materials at low temperatures. Helium leak tests on face seals were used to compare the materials. Materials tested include butyl, neoprene, ethylene propylene, fuorosilicone, silicone, Eypel, Kalrez, Teflon, fluorocarbon, and Teflon/silicone composites. Results show that the seal materials tested, with the exception of silicone S613-60, are not leak tight at manufacturer low-temperature ratings. This paper documents the initial series of experiments developed to characterize the performance of several static seals under conditions representative of RAM transport container environments. Helium leak rates of face seals were measured at low and ambient temperatures to compare seal materials. As scaling laws have not been developed for seals, the leakage rates measured in this program are intended to be used in a qualitative rather than quantitative manner. 5 refs., 7 figs., 2 tabs.
Date: January 1, 1991
Creator: Madsen, M.M.; Edwards, K.R. & Humphreys, D.L.
Partner: UNT Libraries Government Documents Department