63,413 research outputs found

    Slosh alleviator Patent

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    Slosh and swirl alleviator for liquid propellant tanks during transport and fligh

    X-ray determination of parts alignment

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    A method for determining the alignment of adjoining metal objects is provided. The method comprises producing an X-ray image of adjoining surfaces of the two metal objects. The X-ray beam is tangential to the point the surfaces are joined. The method is particularly applicable where the alignment of the two metal objects is not readily susceptible to visual inspection

    A Critical Introduction

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    Description of a new genus and species of hummingbird from Panama

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    Since January, 1911, Mr. E. A. Goldman, of the Biological Survey, U.S.Department of Agriculture, has been detailed to the Smithsonian Biological Survey of the Panama Canal Zone to collect mammals and birds in the Canal Zone and adjacent parts of Panama... (Document contains 4 pages

    Fluid Borders, Concrete Locations: Epicenters of Cross-Cultural Interaction in the Eighteenth Century Borderland of the Great Lakes

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    In a recent article on the advent of borderlands history as a prominent field of historical scholarship, Pekka Hämäläinen and Samuel Truett described borderlands as “realms where boundaries are also crossroads, peripheries are also central places, homelands are also passing-through places, and the end points of empire are also forks in the road.” One such region that certainly fits this definition of a borderland and unquestionably hosts such specific crossroads and cultural junctions is the maritime region of the Great Lakes of North America. [excerpt

    Application of NASTRAN to a fluid solids unit in the petroleum industry

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    The application of NASTRAN to the design of a fluid solids unit plenum/cyclone/dipleg assembly is described. The major loads considered are thermal, pressure, and gravity. Such applications are of interest in the petroleum industry since the equipment described is historically critical

    The Minority Experience at Gettysburg College: The Hanson Years (1961-1977)

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    The years of C. Arnold Hanson’s term as president at Gettysburg College were years of turbulence, change, and challenge. Rising to the position of president in 1961, in the dawning of a dynamic era of modern American history, C. A. Hanson served well into the middle of the next decade, during which time he helped guide Gettysburg College through some of its most trying and vital changes. This was the era of the hippie and the free thinker, the era of the Women’s and Civil Rights Movements, the era of Vietnam and anti-war protests, the era that shaped modern American society and culture. During this period, one of the areas in which the most dramatic changes occurred was in the sphere of Civil Rights; Gettysburg was far from the forefront in dealing with bigotry, but it did confront the race issue. As this occurred on the national scale, efforts were made at Gettysburg to follow suit. Sadly, this was often difficult and unsuccessful, occurring “in fits and starts.” During C. A. Hanson’s tenure as president, minorities experienced discrimination as they pursued equal opportunities in education, faculty and administrators struggled to construct a successful strategy for integration, students brought down racial barriers through interaction, and above all, many African Americans demonstrated extraordinary strength of character in their fight for equality and acceptance into the Gettysburg College community. [excerpt

    Fighter aircraft flight control technology design requirements

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    The evolution of fighter aircraft flight control technology is briefly surveyed. Systems engineering, battle damage considerations for adaptive flutter suppression, in-flight simulation, and artificial intelligence are briefly discussed

    Posttranslational control of membrane-skeleton (ankyrin and alpha beta- spectrin) assembly in early myogenesis

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    Adult chicken skeletal muscle cells express polypeptides that are antigenically related to alpha-spectrin (Mr 240,000) and beta-spectrin (Mr 220,000-225,000), the major components of the erythrocyte membrane- skeleton, and to ankyrin (Mr 237,000; also termed goblin in chicken erythrocytes), which binds spectrin to the transmembrane anion transporter in erythrocytes. Comparative immunoblotting of SDS- solubilized extracts of presumptive myoblasts and fully differentiated myotubes cultured in vitro demonstrated that there is a dramatic accumulation of ankyrin and alpha- and beta-spectrin during myogenesis and a concomitant switch in the subunit composition of spectrin from alpha gamma to alpha beta. Analysis of early time points in myogenesis (12-96 h) revealed that these changes occur shortly after the main burst of cell fusion. To determine the temporal relationship between cell fusion and the accumulation of ankyrin and alpha- and beta- spectrin, we treated presumptive myoblasts with 2 mM EGTA, which resulted in the complete inhibition of cell fusion. The incorporation of [35S]methionine into total protein and, specifically, into alpha-, gamma-, and beta-spectrin remained the same in EGTA-treated and control cells. Analysis by immunoblotting of the amounts of ankyrin and alpha- and beta-spectrin in fusion-blocked cells revealed that there was no effect on accumulation for the first 19 h. However, there was then a dramatic cessation in their accumulation, and thereafter, the amount of each protein at steady state remained constant. Upon release from the EGTA block, the cells fused rapidly (less than 11 h), and the accumulation of ankyrin and alpha- and beta-spectrin was reinitiated after a lag period of 3-5 h at a rate similar to that in control cells. The inhibition in the accumulation of newly synthesized ankyrin, alpha- spectrin, and beta-spectrin in EGTA-treated myoblasts was not characteristic of all structural proteins, since the accumulation of the muscle-specific intermediate filament protein desmin was the same in control and fusion-blocked cells. These results show that in myogenesis, the synthesis of ankyrin and alpha- and beta-spectrin and their accumulation as a complex, although concurrent, are not coupled events. We hypothesize that the extent of assembly of these components of the membrane-skeleton in muscle cells is determined by a control mechanism(s) operative at the posttranslational level that is triggered near the time of cell fusion and the onset of terminal differentiation
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