642 research outputs found

    Performance of unconventional propellants

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    This research involves the theoretical calculations of rocket performance for exotic propellants at various operating conditions, such as chamber pressure, pressure ratios, and oxidizer-to-fuel ratios. Exotic propellants are materials that may not normally be used as propellants on earth due to their low performance characteristics or other factors. The majority of the work was done using the Gordon and McBride CET 86 Program in both a mainframe version and personal computer versions. In addition, the Lockheed/Air Force Solid Propellant Theoretical Performance Program for the IBM PS/2, which handles condensed product species better, was also used

    Surface Phase Diagrams for Wetting on Heterogenous Substrates

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    We propose a simplified description of fluid adsorption on heterogenenous micropatterned substrates. Using this approach, we are able to rederive results obtained earlier using effective interfacial Hamiltonian methods and predict a number of new examples of surface phase behaviour for both singly and periodically striped substrates. In particular, we show that, for a singly striped system, the manner in which the locus of surface unbending phase transitions approaches the pre-wetting line of the infinite pure system, in the limit of large stripe widths, is non-trivial and sensitive to several characteristic lengthscales and competing free-energies. For periodic substrates, we investigate finite-size deviations from Cassie's law for the wetting temperature of the heterogeneous system when the domain sizes are mesoscopic.Comment: 12 pages, 13 figure

    Solid-to-solid isostructural transition in the hard sphere/attractive Yukawa system

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    A thermodynamically consistent density functional-perturbation theory is used to study the isostructural solid-to-solid transition which takes place in the hard sphere/attractive Yukawa system when the Yukawa tail is sufficiently short-ranged. A comparison with results for the square well potential allows us to study the effect of the attractive potential form on the solid-solid transition. Reasonable agreement with simulations is found for the main transition properties as well as for the phase diagram evolution with the the range of the attractive potential.Comment: 14 pages, latex, 5 figures available upon request: ([email protected]

    The Five Paragraph Essay

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    Documento: aprenda a estructurar sus ensayos usando el enfoque de cinco párrafos.DOC: learn how to structure your essays using the Five Paragraph Essay approach

    Effective Thesis Statements

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    Las afirmaciones de tesis al principio de un párrafo son absolutamente clave para construir un ensayo académico que fluya y se lea fácilmente.Effective thesis statements at the beginning of a paragraph are absolutely key to building an academic essay that flows and reads easily

    Professional Correspondence

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    La correspondencia profesional generalmente es por correo electrónico, sin embargo en contextos más formales un formato de carta es más apropiado. Este documento describe dos formatos estándar que se utilizan comúnmente.DOC: Professional correspondence generally is by e-mail, however in more formal contexts a letter format is more appropriate. This document outlines two standard formats that are commonly used
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