Flame retardant spandex type polyurethanes

Flame retardant elastomeric compositions were developed, comprised of: (1) spandex type polyurethane having incorporated into the polymer chain, halogen containing polyols; (2) conventional spandex type polyurethanes in physical admixture flame retardant additives; and (3) fluoroelastomeric resins in physical admixture with flame retardant additives. Methods of preparing fibers of the flame retardant elastomeric materials are presented and articles of manufacture comprised of the elastomeric materials are mentioned

Flame resistant elastic elastomeric fiber

Compositions exhibit elastomeric properties and possess various degrees of flame resistance. First material polyurethane, incorporates halogen containing polyol and is flame resistant in air; second contains spandex elastomer with flame retardant additives; and third material is prepared from fluorelastomer composition of copolymer of vinylidene fluoride and hexafluoropropylene

Flame resistant elastomeric polymer development

Elastomeric products were developed for use in the space shuttle program, and investigations were conducted to improve the properties of elastomers developed in previous programs, and to evaluate the possibility of using lower-cost general purpose polymers. Products were fabricated and processed on conventional processing equipment; these products include: foams based on fluorinated rubber flame-retarded compounds with a density of 20-30 pounds/cubic foot for use as padding and in helmets; foams based on urethane for use in instrument packaging in the space shuttle; flexible and semi-rigid films of fluorinated rubber and neoprene compounds that would not burn in a 70% nitrogen, 30% oxygen atmosphere, and in a 30% nitrogen, 70% oxygen atmosphere, respectively for use in packaging or in laminates; coated fabrics which used both nylon and Kelvar fabric substrates, coated with either fluorinated or neoprene polymer compositions to meet specific levels of flame retardancy; and other flame-resistant materials

Non-flammable elastomeric fiber from a fluorinated elastomer and containing an halogenated flame retardant

Flame retardant elastomeric compositions are described comprised of either spandex type polyurethane having incorporated into the polymer chain halogen containing polyols, conventional spandex type polyurethanes in physical admixture with flame retardant additives, or fluoroelastomeric resins in physical admixture with flame retardant additives. Methods are described for preparing fibers of the flame retardant elastomeric materials and articles of manufacture comprised of the flame retardant clastomeric materials and non elastic materials such as polybenzimidazoles, fiberglass, nylons, etc

Informal Agency Rulemaking and the Courts: A Theory for Procedural Rreview

This Article will demonstrate that judicial review of agency rulemaking procedures, if properly structured, is an acceptable and important tool for the control of regulatory policy-making. The procedural discretion of administrative rulemakers should not be as broad as Vermont Yankee suggests. The first part of this Article will identify the procedural values which should serve as normative guides to the adequacy and legitimacy of informal rulemaking. The second part will examine the Supreme Court\u27s opinion in Vermont Yankee, criticizing its approach to procedural review of informal rulemaking as a threat to the integrity of that rulemaking process. In the third section of the Article, the judicial and scholarly reactions to Vermont Yankee will be examined and critiqued. It is clear that neither the courts nor the commentators have yet succeeded in developing an approach to procedural review of informal rulemaking which adequately responds to the problems created by Vermont Yankee. The Article will conclude with a suggested theory for procedural review of informal rulemaking. This theory will present an instrumental interpretation of section 553 of the APA which establishes the minimum procedural requirements needed to preserve the procedural values that insure the integrity of informal rulemaking. The theory will also outline a method and supporting rationale for judicial review of the discretionary procedural decisions of agency rulemakers—decisions by agencies to employ (or not employ) additional rulemaking procedures beyond those minimally required by the APA

A detailed X-ray investigation of zeta Puppis IV. Further characterization of the variability

Previously, the X-ray emission of zeta Puppis was found to be variable with light curves harbouring "trends" with a typical timescale longer than the exposure length. The origin of these changes was proposed to be linked to large-scale structures in the wind, but further characterization of the variability at high energies was needed. Since then, a number of new X-ray observations have become available. Furthermore, a cyclic behaviour with a 1.78d period was identified in long optical photometric runs, which is thought to be associated with the launching mechanism of large-scale wind structures. We analysed these new X-ray data, revisited the old data, and compared X-ray with optical data, including when simultaneous. We found that the behaviour in X-rays cannot be explained in terms of a perfect clock because the amplitude and shape of its variations change with time. For example, zeta Puppis was much more strongly variable between 2007 and 2011 than before and after this interval. Comparing the X-ray spectra of the star at maximum and minimum brightness yields no compelling difference beyond the overall flux change: the temperatures, absorptions, and line shapes seem to remain constant, well within errors. The only common feature between X-ray datasets is that the variation amplitudes appear maximum in the medium (0.6-1.2keV) energy band. Finally, no clear and coherent correlation can be found between simultaneous X-ray and optical data. Only a subgroup of observations may be combined coherently with the optical period of 1.78d, although the simultaneous optical behaviour is unknown. The currently available data do not reveal any obvious, permanent, and direct correlation between X-ray and optical variations. The origin of the X-ray variability therefore still needs to be ascertained, highlighting the need for long-term monitoring in multiwavelengths, i.e. X-ray, UV, and optical.Comment: accepted for publication by A&

Greenhouse gas emissions from domestic hot water: heat pumps compared to most commonly used systems

We estimate the emissions of the two most important greenhouse gasses (GHG), carbon dioxide (CO2) and methane (CH4), from the use of modern high-efficiency heat pump water heaters compared to the most commonly used domestic hot water systems: natural gas storage tanks, tankless natural gas demand heaters, electric resistance storage tanks, and tankless electric resistance heaters. We considered both natural gas-powered electric plants and coal-powered plants as the source of the electricity for the heat pumps, the thermal electric storage tanks, and the tankless electric demand heaters. The time-integrated radiative forcing associated with using a heat pump water heater was always smaller than any other means of heating water considered in this study across all time frames including at 20 and 100 years. The estimated amount of CH4 lost during its lifecycle was the most critical factor determining the relative magnitude of the climatic impact. The greatest net climatic benefit within the 20-year time frame was predicted to be achieved when a storage natural gas water heater (the most common system for domestic hot water in the United States) fueled by shale gas was replaced with a high efficiency heat pump water heater powered by coal-generated electricity; the heat pump system powered by renewable electricity would have had an even greater climatic benefit, but was not explicitly modeled in this study. Our analysis provides the first assessment of the GHG footprint associated with using a heat pump water heater, which we demonstrate to be an effective and economically viable way of reducing emissions of GHGs.This study was funded by the Wallace Global Fund, the Park Foundation, and Cornell University

Surface abundances of ON stars

Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient, or when mass transfer in binary systems happens, chemically processed material is observed at the surface of O and B stars. ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle or not is not known. Our goal is to answer this question. We perform a spectroscopic analysis of a sample of ON stars with atmosphere models. We determine the fundamental parameters as well as the He, C, N, and O surface abundances. We also measure the projected rotational velocities. We compare the properties of the ON stars to those of normal O stars. We show that ON stars are usually helium-rich. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate - on average - faster than normal O stars. Evolutionary models including rotation cannot account for the extreme enrichment observed among ON main sequence stars. Some ON stars are members of binary systems, but others are single stars as indicated by stable radial velocities. Hence, mass transfer is not a simple explanation for the observed chemical properties. We conclude that ON stars show extreme chemical enrichment at their surface, consistent with nucleosynthesis through the CNO cycle. Its origin is not clear at present.Comment: 18 pages, 10 figures (+ appendix). A&A accepte

Amplitude variability in satellite photometry of the non-radially pulsating O9.5V star zeta Oph

We report a time-series analysis of satellite photometry of the non-radially pulsating Oe star zeta Oph, principally using data from SMEI obtained 2003--2008, but augmented with MOST and WIRE results. Amplitudes of the strongest photometric signals, at 5.18, 2.96, and 2.67/d, each vary independently over the 6-year monitoring period (from ca. 30 to <2 mmag at 5.18/d), on timescales of hundreds of days. Signals at 7.19/d and 5.18/d have persisted (or recurred) for around two decades. Supplementary spectroscopic observations show an H-alpha emission episode in 2006; this coincided with small increases in amplitudes of the three strongest photometric signals.Comment: MNRAS, in pres