3,396 research outputs found

    A Deep Multicolor Survey I. Imaging Observations and Catalog of Stellar Objects

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    We have used the KPNO 4-meter Mayall telescope to image 0.83 square degrees of sky in six fields at high galactic latitude in six filters spanning 3000-10000\AA\ to magnitude limits ranging from 22.1 to 23.8. We have assembled a catalog of 21,375 stellar objects detected in the fields for use primarily in conducting a multicolor search for quasars. This paper describes the data reduction techniques used on the CCD data, the methods used to construct the stellar object catalog, and the simulations performed to understand its completeness and contamination.Comment: To Appear in ApJ Supplement, 1996. 168k uuencoded gunzipped tarred tex file (requires aas2pp4.sty and tighten.sty) and 4 PostScript figures. Also available at http://astro.as.arizona.edu/~pathall/astro.html#preprint

    Transhumanism and Catholic Natural Law: Changing Human Nature and Changing Moral Norms?

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    In this chapter I propose a preliminary response to the transhumanist challenge to natural law by investigating six basic questions: ( 1) Is human nature relevant to morality? (2) Is human nature mutable? (3) How would we know if human nature had changed? ( 4) Could cultural evolution replace biological evolution? (5) How would human nature and human will relate to each other under these new transhuman conditions? (6) Is it possible to construct a dynamic ethic to fit a dynamic nature, and if so, what might that ethic be? Overall, I argue that it is possible to maintain a natural law ethics approach in the face of transhumanist changes to human nature and that, in fact, doing so remains a very useful approach, albeit one with some difficulties. The norms of natural law are another matter: I think moral norms will need to become either stricter than in the past or different in ways that are difficult to anticipate. This chapter concentrates on the philosophy and theology of the 13th century Roman Catholic saint, Thomas Aquinas, who developed Aristotle\u27s ideas in a Christian context. Aquinas\u27s claims that action follows being and that human nature is a composite of first nature and second nature are combined with ideas from the philosopher Hans Jonas about the increasing scope of human action and the consequent necessity to update ethics. I propose that there a new form of natural law ethics might be capable of responding to changes in human nature

    Benefits of Including SAE Bolts, Nuts, and Washers in the AISI STANDARD S100

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    The addition of SAE J429 bolts along with their associated nuts and washers into the AISI STANDARD S100, North American Specification for the Design of Cold-Formed Members, would be a significant enhancement to the specification by providing practitioners the opportunity to use a broader range of fasteners for the design of cold-formed steel structures. The design of bolted connections using SAE J429 bolts would be advantageous for many types of structures including mechanical support structures, storage rack systems, photovoltaic support structures, carport structures, and conventional repetitive frame structures that all utilize cold-formed steel members. These structures would benefit by having a more robust range of smaller diameter fasteners available that are not found in ASTM A307 common bolts or ASTM F3125 Grades A325 or A490 high-strength structural bolts. Many industries that require small diameter fasteners already use SAE J429 bolts or have attempted to use SAE bolts in their designs without any specification guidance. Incorporation of SAE J429 bolts into AISI STANDARD S100 requires a comparison between the ASTM bolts currently recognized in the Standard with those SAE bolts looking to be included in the specification. This comparison would need to cover: 1) Geometry of the bolt, nut, and washer,2) Bearing strength of connections,3) Shear strength of SAE bolts,4) Tension strength of SAE bolts, and5) Assurance of quality. This comparison would also need to demonstrate that SAE J429 bolted connections will provide designs with an equivalent level of safety or resistance as do ASTM bolts. The following sections address these issues and provide the reasons or benefits for their proposed inclusion in the next edition of the AISI Standard