137 research outputs found

    Rr2004 Test1 and 4 Data Analysis

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    Test 1 data analysis for Kydex, Royal Blue Cotton, and Silicon along with test 4 data analysis for Raychem Electrical Wire is presented

    An Approach to Evaluate Precision and Inter-Laboratory Variability of Flammability Test Methods for Aerospace Materials

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    Materials selection for spacecraft is based on conventional flammability or ignition sensitivity acceptance tests. Current procedures for determining the inter-laboratory repeatability and reproducibility of aerospace materials flammability tests are not considering the dependence of data variability on test conditions and consequently attempts to characterize the precision of these methods were not successful. The inter-laboratory data variability is determined with tests conducted under arbitrary conditions, which consequently may not provide sufficient information to enable adequate determination of a method's precision. For evaluating the precision of NASA's flammability test methods, the protocol recommended includes selecting critical parameters and determining the 50% failure point by considering the specific failure criteria of each method using the critical parameter as a variable. Upon performing inter-laboratory round robin testing using this approach, the laboratories' performance could be evaluated by comparing the repeatability of the 50% failure point and/or the repeatability of critical conditions where the probabilities of passing and failing are unity, i.e., the transition zone repeatability. When a sufficient amount of data has been acquired with this method, an adequate estimation of precision of aerospace materials flammability test methods will be possible

    Enantioselective Organocatalytic α-Fluorination of Aldehydes

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    The first direct enantioselective catalytic α-fluorination of aldehydes has been accomplished. The use of enamine catalysis has provided a new organocatalytic strategy for the enantioselective fluorination of aldehydes to generate α-fluoro aldehydes, an important chiral synthon for medicinal agent synthesis. The use of imidazolidinone 1 as the asymmetric catalyst has been found to mediate the fluorination of a large variety of aldehyde substrates with N-fluorobenzenesulfonimide serving as the electrophilic source of fluorine. A diverse spectrum of aldehyde substrates can also be accommodated in this new organocatalytic transformation. While catalyst quantities of 20 mol % were generally employed in this study, successful halogenation can be accomplished using catalyst loadings as low as 2.5 mol %

    Remarks on Flammability Testing of Aerospace Materials

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    Agenda for the presentation: (1) Brief background of ISO 16697 (a) Reasons for the approach (b) Stated intent for this International Technical Specification (2) Evolution of initial considerations for the ISO approach (3) Discussion and recommendatio

    An Advanced, Three-Dimensional Plotting Library for Astronomy

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    We present a new, three-dimensional (3D) plotting library with advanced features, and support for standard and enhanced display devices. The library - S2PLOT - is written in C and can be used by C, C++ and FORTRAN programs on GNU/Linux and Apple/OSX systems. S2PLOT draws objects in a 3D (x,y,z) Cartesian space and the user interactively controls how this space is rendered at run time. With a PGPLOT inspired interface, S2PLOT provides astronomers with elegant techniques for displaying and exploring 3D data sets directly from their program code, and the potential to use stereoscopic and dome display devices. The S2PLOT architecture supports dynamic geometry and can be used to plot time-evolving data sets, such as might be produced by simulation codes. In this paper, we introduce S2PLOT to the astronomical community, describe its potential applications, and present some example uses of the library.Comment: 12 pages, 10 eps figures (higher resolution versions available from http://astronomy.swin.edu.au/s2plot/paperfigures). The S2PLOT library is available for download from http://astronomy.swin.edu.au/s2plo

    Applicability of ISO 16697 Data to Spacecraft Fire Fighting Strategies

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    Presentation Agenda: (1) Selected variables affecting oxygen consumption during spacecraft fires, (2) General overview of ISO 16697, (3) Estimated amounts of material consumed during combustion in typical ISS enclosures, (4) Discussion on potential applications

    Enantioselective Organocatalytic a-Fluorination of Aldehydes

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    Oxygen Concentration Flammability Thresholds of Selected Aerospace Materials Considered for the Constellation Program

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    Materials selection for spacecraft is based on an upward flammability test conducted in a quiescent environment in the highest expected oxygen concentration environment. The test conditions and its pass/fail test logic do not provide sufficient quantitative materials flammability information for an advanced space exploration program. A modified approach has been suggested determination of materials self-extinguishment limits. The flammability threshold information will allow NASA to identify materials with increased flammability risk from oxygen concentration and total pressure changes, minimize potential impacts, and allow for development of sound requirements for new spacecraft and extraterrestrial landers and habitats. This paper provides data on oxygen concentration self-extinguishment limits under quiescent conditions for selected materials considered for the Constellation Program
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