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    Homological finiteness conditions for groups, monoids and algebras

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    Recently Alonso and Hermiller introduced a homological finiteness condition\break biFPnbi{-}FP_n (here called {\it weak} biFPnbi{-}FP_n) for monoid rings, and Kobayashi and Otto introduced a different property, also called biFPnbi{-}FP_n (we adhere to their terminology). From these and other papers we know that: biFPnbi{-}FP_n \Rightarrow left and right FPnFP_n \Rightarrow weak biFPnbi{-}FP_n; the first implication is not reversible in general; the second implication is reversible for group rings. We show that the second implication is reversible in general, even for arbitrary associative algebras (Theorem 1'), and we show that the first implication {\it is} reversible for group rings (Theorem 2). We also show that the all four properties are equivalent for connected graded algebras (Theorem 4). A result on retractions (Theorem 3') is proved, and some questions are raised.Comment: 10 page

    Environmental effects on composites for aircraft

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    The influence of the operational environment on the behavior of composite materials and aircraft components fabricated with these composite materials was considered. Structural weight savings, manufacturing cost savings, and long-term environmental durability are among the factors examined. The flight service experience to date of composite components is evaluated. In addition, the influence of a number of worldwide, ground based outdoor exposures on the physical and mechanical properties of six composite materials is discussed. In particular, the current extent of the ultraviolet surface degradation and the moisture gained by diffusion is shown

    Black, Yellow, Red & White

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    On Pride

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    In this essay, I offer a vindication of pride. I start by presenting the Christian condemnation of pride as the cardinal sin. I subsequently examine Mandeville’s line of argument whereby pride is beneficial to society, although remaining a vice for the individual. Finally, I focus on, and endorse, the analysis of pride formulated by Hume, for whom pride qualifies instead as a virtue. This is because pride not only contributes to making society flourish but also stabilizes the virtuous agent by creating a virtuous circle between our desire for self-appraisal and our aspiration to act morally. I conclude by underscoring the (virtuous) connection between pride and modesty, concomitantly arguing that humility should be discarded as vicious

    Points of Pride

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    End-to-end testing

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    The principle objective of the kinds of demonstration tests that are discussed is to try to verify whether or not carbon fibers that are released by burning composite parts in an aircraft-fuel fires can produce failures in electrical equipment. A secondary objective discussed is to experimentally validate the analytical models for some of the key elements in the risk analysis. The approach to this demonstration testing is twofold: limited end-to-end test are to be conducted in a shock tube; and planning for some large outdoor burn tests is being done
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