20,162 research outputs found

    Monomers for thermosetting and toughening epoxy resins

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    Eight glycidyl amines were prepared by alkylating the parent amine with epichlorohydrin to form chlorohydrin, followed by cyclization with aqueous NaOH. Three of these compounds contained propargyl groups with postcuring studies. A procedure for quantitatively estimating the epoxy content of these glycidyl amines was employed for purity determination. Two diamond carbonates and several model propargly compounds were prepared. The synthesis of three new diamines, two which contain propargyloxy groups, and another with a sec-butyl group is in progress. These materials are at the dinitro stage ready for the final hydrogenation step. Four aromatic diamines were synthesized for mutagenic testing purposes. One of these compounds rapidly decomposes on exposure to air

    Leadership and capability development and deployment in the New Zealand State Service

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    This article describes the design during 2013 of a model and implementation principles of a leadership and capability development and deployment (LCDD) model for the state services system. In this process, an initial prototype model was developed to describe a desired future state. It was informed by the best traditions of state services leadership development, together with models used by the world’s best companies, such as Procter & Gamble, for leadership development (Filipkowski and Donlon, 2013). The model was then enhanced based on our research in other jurisdictions, including Australia, Singapore and the United Kingdom, and co-creation with stakeholders. This is further discussed in the article. Dr Mike Pratt is Professor of Leadership and Sustainability at the University of Waikato, and a professional director and business adviser. Dr Murray Horn is a former Secretary to the Treasury of New Zealand and bank chief executive, and a professional director and business adviser

    Processable polyimide adhesive and matrix composite resin

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    A high temperature polyimide composition prepared by reacting 4,4'-isophthaloyldiphthalic anhydride with metaphenylenediamine is employed to prepare matrix resins, adhesives, films, coatings, moldings, and laminates, especially those showing enhanced flow with retention of mechanical and adhesive properties. It can be used in the aerospace industry, for example, in joining metals to metals or metals to composite structures. One area of application is in the manufacture of lighter and stronger aircraft and spacecraft structures

    Investigation of the effects of short chain processing additives on polymers

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    The effects of low level concentrations of several short chain processing additives on the properties of the 4,4'-bis(3,4-dicarboxyphenoxy) diphenylsulfide dianhydride (BDSDA)/4,4'-diaminodiphenyl ether (ODA)/1,3'-diaminobenzene (m-phenylene diamine) (MPA) (422) copolyimide were investigated. It was noted that 5 percent MPD/phthalic anhydride (PA) is more effective than 5 percent ODA/PA and BDSDA/aniline (AN) in strengthening the host material. However, the introduction of 10 percent BDSDA/AN produces disproportionately high effects on free volume and free electron density in the host copolyimide

    Fabrication process of a high temperature polymer matrix engine duct

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    The process that was used in the molding of an advanced composite outer by-pass duct planned for the F404 engine is discussed. This duct was developed as a potential replacement for the existing titanium duct in order to reduce both the weight and cost of the duct. The composite duct is now going into the manufacturing technology portion of the program. The duct is fabricated using graphite cloth impregnated with the PMR-15 matrix system

    The Growth and Survival of Early Instars of \u3ci\u3eBellura Obliqua\u3c/i\u3e (Lepidoptera: Noctuidae) on \u3ci\u3eTypha Latifolia\u3c/i\u3e and \u3ci\u3eTypha Angustifolia\u3c/i\u3e

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    Larvae of the noctuid moth Bellura obliqua are frequently encountered on Typha latifolia, but less commonly on Typha angustifolia. Experiments were conducted to compare the growth and survivorship of early B. obliqua instars on the two species of cattail. In short-term growth chamber experiments there were no significant differences in the survivorship, relative growth rate (RGR), relative consumption rate (RCR), or the efficiency of conversion of ingested food (ECI) between first-instar larvae reared on leaves of the two species. Third-instar larvae fed stems, however, had a greater RGR and higher ECI when reared on T. lalifolia. Differences in growth are apparently not related to differences in hostplant nitrogen or acid-detergent fiber content. In a long term greenhouse experiment, using transplanted cattails, larvae reared on T. latifolia grew somewhat larger and had a significantly higher survival rate than those reared on T. angustifolia. Host plant structure is postulated to influence larval survivorship. Typha is under consideration for use as a bio-energy crop and planting T. angustifolia may help to reduce infestations in cultivated stands
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