1,908 research outputs found

    Biaxial Stress Limit for ULDB Film

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    The current ULDB design applies stress to the shell film biaxially to control creep in the latitudinal direction. The recent change in design paradigm, from a uniaxial to biaxial stress state basis, arose from a new perspective that the biaxial loading can control strain in both principal surface dimensions as discussed below. The current ULDB project path was thus enabled by a more thorough understanding of the nonlinear viscoelastic properties of the shell film material, linear low-density polyethylene (LLDPE). Although a very similar material is also used in NASA zero-pressure (ZPB) and long-duration balloons (LDB), the different stress state requires a new approach to shell material qualification

    The Ursinus Weekly, March 3, 1958

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    Campus Chest drive opens; Goal is $1500 • Special editorial: A time for action! • Manager names pageant, court for 1958 May Day • 3 members resign at MSGA meeting on rules issue • M. Zippin speaks on contemporary and abstract art • Student-faculty show set; March 14 • Printer, photographer of \u2759 Ruby announced • Campus Chest lists four charities; Dinner held for campus leaders • Seniors present melodrama Gold in the hills, Mar. 7-8 • Supply Store to buy texts Mar. 6 • Chi Alpha to discuss play by Sartre; No exit • Editorial: There was weeping and wailing • Wasted hours in class • Old philosopher • Ursinians in Spain • Letters to the editor • Season ends for cagemen; Lose to Drexel, J. Hopkins • Matmen trounce Dragons, 24 to 8, in final match • J. Prutzman second in M.A.C. held at Wilkes • Companies offer Summer positions • Community Club to show fashionshttps://digitalcommons.ursinus.edu/weekly/1401/thumbnail.jp

    Dichotomy of Solar Coronal Jets: Standard Jets and Blowout Jets

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    By examining many X-ray jets in Hinode/XRT coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H alpha macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major CMEs. From the coronal X-ray movies we present in detail two typical standard X-ray jets and two typical blowout X-ray jets that were also caught in He II 304 Angstrom snapshots from STEREO/EUVI. The distinguishing features of blowout X-ray jets are (1) X-ray brightening inside the base arch in addition to the outside bright point that standard jets have, (2) blowout eruption of the base arch's core field, often carrying a filament of cool (T ~10(exp 4) - 10(exp 5) K) plasma, and (3) an extra jet-spire strand rooted close to the bright point. We present cartoons showing how reconnection during blowout eruption of the base arch could produce the observed features of blowout X-ray jets. We infer that (1) the standard-jet/blowout-jet dichotomy of coronal jets results from the dichotomy of base arches that do not have and base arches that do have enough shear and twist to erupt open, and (2) there is a large class of spicules that are standard jets and a comparably large class of spicules that are blowout jets

    Discovery of Enhanced Germanium Abundances in Planetary Nebulae with FUSE

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    We report the discovery of Ge III Îť\lambda1088.46 in the planetary nebulae (PNe) SwSt 1, BD+30o^{\rm o}3639, NGC 3132, and IC 4593, observed with the Far Ultraviolet Spectroscopic Explorer. This is the first astronomical detection of this line and the first measurement of Ge (Z = 32) in PNe. We estimate Ge abundances using S and Fe as reference elements, for a range of assumptions about gas-phase depletions. The results indicate that Ge, which is synthesized in the initial steps of the s-process and therefore can be self-enriched in PNe, is enhanced by factors of > 3-10. The strongest evidence for enrichment is seen for PNe with Wolf-Rayet central stars, which are likely to contain heavily processed material.Comment: 11 pages, 1 figure, accepted for publication in ApJ Letter

    Deductive synthesis of recursive plans in linear logic

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    Linear logic has previously been shown to be suitable for describing and deductively solving planning problems involving conjunction and disjunction. We introduce a recursively defined datatype and a corresponding induction rule, thereby allowing recursive plans to be synthesised. In order to make explicit the relationship between proofs and plans, we enhance the linear logic deduction rules to handle plans as a form of proof term

    Specializing Interpreters using Offline Partial Deduction

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    We present the latest version of the Logen partial evaluation system for logic programs. In particular we present new binding-types, and show how they can be used to effectively specialise a wide variety of interpreters.We show how to achieve Jones-optimality in a systematic way for several interpreters. Finally, we present and specialise a non-trivial interpreter for a small functional programming language. Experimental results are also presented, highlighting that the Logen system can be a good basis for generating compilers for high-level languages
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