SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS
A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 25 - DECEMBER 16, 2005
27 NONMETALLIC MATERIALS
Includes physical, chemical, and mechanical properties of plastics, elastomers, lubricants, polymers, textiles, adhesives, and ceramic materials.
For composite materials see 24 Composite Materials.
20050240893 Lawrence Livermore National Lab., Livermore, CA USA
Characterization of Thermal Sprayed Aluminum and Stainless Steel Coatings for Clean Laser Enclosures
Chow, R.; Decker, T. A.; Gansert, R. V.; Gansert, D.; Apr. 06, 2000; 18 pp.; In English Report No.(s): DE2005-15013184; UCRL-JC-138734; No Copyright; Avail.: Department of Energy Information Bridge
Surfaces of steel structures that enclose high-fluence, large-beam lasers have conventional and unconventional requirements. Aside from rust prevention, the surfaces must resist laser-induced degradation and the contamination of the optical components. The latter requires a surface that can be precision cleaned to low levels of particulate and organic residue. In addition, the surface treatment for the walls should be economical to apply because of the large surface areas involved, and accommodating with intricate joint geometries. Thermal sprayed coatings of aluminum (Al) and stainless steel are candidate surface materials. Coatings are produced and characterized for porosity, smoothness, and hardness. These properties have a bearing on the cleanliness of the coating. The laser resistance of Al and 316L coatings are given. The paper summarizes the characterization of twin-wire-arc deposited Al, high-velocity-oxygen-fueled (HVOF) deposited Al, flame-sprayed 316L, and HVOF deposited 316L. NTIS
Aluminum Coatings; Lasers; Stainless Steels
20050240910 Forest Products Lab., Madison, WI USA, Purdue Univ., West Lafayette, IN USA
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Wood Finishing: Paint Failure Problems and Their Cure
Cassens, D. L.; Feist, W. C.; January 2005; 10 pp.; In English Report No.(s): PB2006-100995; NCRE/PUB-133; No Copyright; Avail.: CASI: A02, Hardcopy
Paint is probably the most common exterior finish in use on wood today.
It appears somewhere on practically every house and most commercial buildings.
Even brick and aluminum sided houses usually have some painted wood trim.
When properly applied to the appropriate type of wood substrate, paint can give a service life of up to 10 years.
All too often, however, problems may develop during the application of the paint or the paint coat fails to achieve the expected service life.
This bulletin will describe various paint problems and will provide information on how to correct or prevent them.
NTIS
Failure; Paints; Wood; Wooden Structures
20050240915 Forest Products Lab., Madison, WI USA, Purdue Univ., West Lafayette, IN USA
Wood Finishing: Discoloration of House Paint, Causes and Cures
Cassens, D. L.; Feist, W. C.; January 2005; 10 pp.; In English Report No.(s): PB2006-100996; NCRE/PUB-134; No Copyright; Avail.: CASI: A02, Hardcopy
Under normal conditions paint deteriorates by first soiling or by a slight accumulation of dirt. Next, a flattening stage develops when the coating gradually starts to chalk and erode away. Unfortunately, paint is sometimes discolored by mildew, blue stain, wood extratives and metals long before repainting is necessary. In these cases, a simple repainting will not correct the problem for long. Furthermore, excessive painting is expensive, and a build-up of paint on the wood surface may lead to cross-grain cracking or other severe paint failures. If the old paint surface is not properly cleaned before repainting, intercoat peeling may also result. NTIS
Cracking (Fracturing); Discoloration; Failure; Paints; Wood
20050240934 Environmental Protection Agency, Washington, DC, USA
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Profile of the Rubber and Plastics Industry, 2nd Edition
EPA Office of Compliance Sector Notebook Project. Feb. 2005; 160 pp.; In English Report No.(s): PB2006-101417; EPA/310/R-05/003; No Copyright; Avail.: CASI: A08, Hardcopy
Environmental policies based upon comprehensive analysis of air, water, and land pollution (such as economic sector and community-based approaches) are becoming an important supplement to traditional single-media approaches to environmental protection. Environmental regulatory agencies are beginning to embrace comprehensive, multistatute solutions to facility permitting, compliance assurance, education/outreach, research, and regulatory development issues. The central concepts driving the new policy direction are that pollutant releases to each environmental medium (air, water and land) affect each other, and that environmental strategies must actively identify and address these interrelationships by designing policies for the 'whole' facility. One way to achieve a whole facility focus is to design environmental policies for similar industrial facilities. By doing so, environmental concerns that are common to the manufacturing of similar products can be addressed in a comprehensive manner. Recognition of the need to develop the industrial sector-based approach within EPAs Office of Compliance led to the creation of this document. NTIS
Industries; Plastics; Rubber; Streams
20050240954 Kentucky Univ., Lexington, KY USA
Environmental Impacts of Bridge Cleaning Operations
Hopwood, T.; Palle, S.; Younce, R.; Feb. 2003; 72 pp.; In English Contract(s)/Grant(s): KYSPR-03-224 Report No.(s): PB2006-101149; KTC-03-03/SPR224-01-1F; No Copyright; Avail.: National Technical Information Service (NTIS)
Cleaning (washing) operations of existing leaded paints on bridges were studied to determine the level of lead contamination in the resulting wastewater. Twelve experimental overcoating projects were let on bridges with various types of existing paint in varying states of deterioration. The projects employed different washing pressures ranging from 2500 psi to 10000 psi and various wash nozzles. Kentucky Transporation Center (KTC) standard filtration was used on 10 projects and 2 projects used an experimental filtration unit having a sand filter and two types of chemical filter media. NTIS
Cleaning; Bridges; Washing
20050241971 Michigan Technological Univ., Houghton, MI, USA
Improvement of Wear Component's Performance by Utilizing Advanced Materials and New Manufacturing Technologies: Castcon Process for Mining Applications. (Report for January 1, 2001-June 30, 2004)
Huang, X.; Gertsch, R.; Feb. 04, 2005; 60 pp.; In English Report No.(s): DE2005-839566; No Copyright; Avail.: Department of Energy Information Bridge
Michigan Technological University, together with The Robbins Group, Advanced Ceramic Research, Advanced Ceramic Manufacturing, and Superior Rock Bits, evaluated a new process and a new material for producing drill bit inserts and disc cutters for the mining industry. Difficulties in the material preparation stage slowed the research initially. Prototype testing of the drill bit inserts showed that the new inserts did not perform up to the current state of the art. Due to difficulties in the prototype production of the disc cutters, the disc cutter was manufactured but not tested. Although much promising information was obtained as a result of this project, the objective of developing an effective means for producing rock drill bits and rock disc cutters that last longer, increase energy efficiency and penetration rate, and lower overall production cost was not met. NTIS
Cutters; Manufacturing; Mining; Tungsten Carbides; Wear
20050243010 North Carolina State Univ., Raleigh, NC USA
Monte Carlo Simulation of a Solvated Ionic Polymer with Cluster Morphology
Matthews, Jessica L.; Lada, Emily K.; Weiland, Lisa M.; Smith, Ralph C.; Leo, Donald J.; Jan. 1, 2005; 31 pp.; In English; Original contains color illustrations Contract(s)/Grant(s): FA9550-04-1-0203 Report No.(s): AD-A439431; No Copyright; Avail.: Defense Technical Information Center (DTIC)
A multiscale modeling approach for the prediction of material stiffness of the ionic polymer Nafion is presented. Traditional rotational isomeric state theory is applied in combination with a Monte Carlo methodology to develop a simulation model of the conformation of Nafion polymer chains on a nanoscopic level from which a large number of end-to-end chain lengths are generated. The probability density function of end-to-end distances is then estimated and used as an input parameter to enhance existing energetics-based macroscale models of ionic polymer behavior. Several methods for estimating the probability density function are compared, including estimation using Johnson distributions, Bezier distributions, and cubic splines. DTIC
Computerized Simulation; Monte Carlo Method; Morphology; Polymers; Solvation
20050243193 Air Force Research Lab., Edwards AFB, CA USA
Synthesis and Characterization of Fluoropropyl POSS
Grabow, Wade; Jul. 1, 2005; 28 pp.; In English Contract(s)/Grant(s): Proj-2303 Report No.(s): AD-A439724; No Copyright; Avail.: Defense Technical Information Center (DTIC)
Fluorinated polyhedral oligomeric silsesquioxanes (POSS) are under investigation for potential lubricant applications. POSS compounds are characterized by a rigid, inorganic core consisting of silicon and oxygen, offering properties similar to those of ceramics; in addition to organic functional groups protruding from the inorganic core, offering organic functionality. Synthesis of POSS generally yields cage mixtures giving varying confirmations of the POSS (Si-O) core denoted by the number of silicon atoms present with T8 being the most abundant conformation. Synthesis of trifluoropropyl-POSS is an exception to this generalization which adopts a preferred T10 conformation, with a minor amount of T8 and T12 isomers. Herein, we describe an alternate synthetic route for the preparation of pure T8 trifluoropropyl-POSS not possible by conventional methods. The POSS cages are characterized by multinuclear NMR as well as low-temperature, single crystal x-ray diffraction studies. DTIC
Fluoropolymers; Oligomers; Siloxanes
20050243399 Savannah River Technology Center, Aiken, SC, USA
Impacts of Uranium and Thorium on the Defense Waste Processing Facility (DWPF) Viscosity Model
Jantzen, C. M.; Feb. 2005; 150 pp.; In English Report No.(s): DE2005-839552; WSRC-TR-2004-00311; No Copyright; Avail.: National Technical Information Service (NTIS)
The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) vitrifies high level liquid waste (HLLW) into borosilicate glass for stabilization and permanent disposal. The viscosity of the borosilicate glass melt as a function of temperature is the single most important variable affecting the melt rate and pour ability of the glass. The viscosity determines the rate of melting of the raw feed, the rate of glass bubble release (foaming and fining), the rate of homogenization, the adequacy of heat transfer, the devitrification rate, and thus, the quality (in terms of glass homogeneity) of the final glass product.
If the viscosity is too low, excessive convection currents can occur during melting, increasing corrosion/erosion of the melter materials of construction (refractory and electrodes) and making control of the melter more difficult. The lowest glass viscosities allowed in the DWPF melter have, therefore, been determined to be approximately 20 poise. DWPF glasses must pour continuously into a large steel canister for ultimate storage in a geologic repository, but glasses with a viscosity greater than or equal to 500 poise do not readily pour. Moreover, too high a viscosity can reduce product quality by causing voids in the final glass. A conservative range of 20-110 poise at a melt temperature, Tmelt or Tm, of 1150 degrees C was, therefore, established for DWPF production.
In summary, a uranium term is not needed in the DWPF viscosity model as long as the U3O8 concentrations of the glasses being melted are less than or equal to 5.76 wt percent, the maximum value examined in this study. The fact that a U-plus-6 term is not needed in the DWPF viscosity model is consistent with the fact that U-plus-6 has four bridging and two non-bridging oxygen bonds. Therefore, the impact of the number of bridging and non-bridging oxygen is approximately equal at U3O8 concentrations of less than or equal to 5.76 wt percent. Uranium may not have an impact at higher U3O8 concentrations but this would have to be demonstrated since the effects of the 0.66:0.33 BO to NBO ratio may become more significant as the U3O8 content increases. NTIS
Thorium; Uranium; Viscosity; Borosilicate Glass
Source: NASA.
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