46 research outputs found

    Development of fire-resistant, low smoke generating, thermally stable end items for aircraft and spacecraft

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    Materials were developed to improve aircraft interior materials by modifying existing polymer structures, refining the process parameters, and by the use of mechanical configurations designed to overcome specific deficiencies. The optimization, selection, and fabrication of five fire resistant, low smoke emitting open cell foams are described for five different types of aircraft cabin structures. These include: resilient foams, laminate floor and wall paneling, thermal/acoustical insulation, molded shapes, and coated fabrics. All five have been produced from essentially the same polyimide precursor and have resulted in significant benefits from transfer of technology between the various tasks

    Development of fire-resistant, low smoke generating, thermally stable end items for commercial aircraft and spacecraft using a basic polyimide resin

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    A terpolyimide precursor was developed which can be foamed by microwave methods and yields foams possessing the best seating properties. A continuous process, based on spray drying techniques, permits production of polyimide powder precursors in large quantities. The constrained rise foaming process permits fabrication of rigid foam panels with improved mechanical properties and almost unlimited density characteristics. Polyimide foam core rigid panels were produced by this technique with woven fiberglass fabric bonded to each side of the panel in a one step microwave process. The fire resistance of polyimide foams was significantly improved by the addition of ceramic fibers to the powder precursors. Foams produced from these compositions are flexible, possess good acoustical attenuation and meet the minimum burnthrough requirements when impinged by high flux flame sources

    A psychometric evaluation of the Learning Styles Questionnaire : 40-item version

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    Sixty-six English-speaking postgraduate distance-education medical students completed the Learning Styles Questionnaire (LSQ: 40-item version). This was completed while attending a residential workshop at the beginning of the semester, and 44 of these students completed the same LSQ questionnaire 5 months later at the completion of the semester. The psychometric properties of the LSQ were assessed using Cronbach’s alpha (internal consistency), test-retest, correlational analyses and factor analysis. The results indicated that the LSQ (40-item version) has poor reliability and validity, and therefore requires further development and psychometric evaluation
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