4,599 research outputs found

    Interactive computer graphics system for structural sizing and analysis of aircraft structures

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    A computerized system for preliminary sizing and analysis of aircraft wing and fuselage structures was described. The system is based upon repeated application of analytical program modules, which are interactively interfaced and sequence-controlled during the iterative design process with the aid of design-oriented graphics software modules. The entire process is initiated and controlled via low-cost interactive graphics terminals driven by a remote computer in a time-sharing mode

    ROBOSIM, a simulator for robotic systems

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    ROBOSIM, a simulator for robotic systems, was developed by NASA to aid in the rapid prototyping of automation. ROBOSIM has allowed the development of improved robotic systems concepts for both earth-based and proposed on-orbit applications while significantly reducing development costs. In a cooperative effort with an area university, ROBOSIM was further developed for use in the classroom as a safe and cost-effective way of allowing students to study robotic systems. Students have used ROBOSIM to study existing robotic systems and systems which they have designed in the classroom. Since an advanced simulator/trainer of this type is beneficial not only to NASA projects and programs but industry and academia as well, NASA is in the process of developing this technology for wider public use. An update on the simulators's new application areas, the improvements made to the simulator's design, and current efforts to ensure the timely transfer of this technology are presented

    The Economic Impact of the Arts, Film, History and Tourism Industries in Connecticut

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    This report contains four ecnomic impact studies corresponding to the four divisions (arts, film, historic preservation, and tourism) of the Connecticut Commission on Culture & Tourism that commissioned them. There is an Executive Summar, the four industry studies, and a methodological overview that includes a discussion of the overall approach, economic impact multipliers, data sources, and an explanation of the conservative nature of the studies.Arts, Film, Historic preservation, heritage, Tourism, travel, impact, Connecticut,

    The designer of the 90's: A live demonstration

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    A survey of design tools to be used by the aircraft designer is given. Structural reliability, maintainability, cost and predictability, and acoustics expert systems are discussed, as well as scheduling, drawing, engineering systems, sizing functions, and standard parts and materials data bases

    U.S. Corporations in Globalization

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    Analysis of 12 AH aerospace nickel-cadmium cells from the design variable program

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    The Design Variable Program of NASA/GSFC provided a systematic approach to evaluate the performance of 12 Ampere-Hour Nickel-Cadmium cells of different designs. Design Variables tested in this program included teflonated negative plates, silver treated negative plates, lightly loaded negative plates, positive plates with no cadmium treatment, plate design of 1968 utilizing old and new processing techniques and electrochemically impregnated positive plates. These cells were life cycled in a Low-Earth Orbit (LEO) regime for 3 to 4 years. Representative cells taken from the Design Variable Program were examined via chemical, electrochemical and surface analyses. The results indicate the following: (1) positive swelling and carbonate content in the electrolyte increase as a function of number of cycles; (2) electrolyte distribution follows a general order NEG greater than POS greater than SEP; (3) control and No PQ groups outperformed the rest of the groups; and (4) the polyproylene group exhibited heavy cadmium migration and poor performance

    Silicon Derived from Glass Bottles as Anode Materials for Lithium Ion Full Cell Batteries.

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    Every year many tons of waste glass end up in landfills without proper recycling, which aggravates the burden of waste disposal in landfill. The conversion from un-recycled glass to favorable materials is of great significance for sustainable strategies. Recently, silicon has been an exceptional anode material towards large-scale energy storage applications, due to its extraordinary lithiation capacity of 3579 mAh g-1 at ambient temperature. Compared with other quartz sources obtained from pre-leaching processes which apply toxic acids and high energy-consuming annealing, an interconnected silicon network is directly derived from glass bottles via magnesiothermic reduction. Carbon-coated glass derived-silicon (gSi@C) electrodes demonstrate excellent electrochemical performance with a capacity of ~1420 mAh g-1 at C/2 after 400 cycles. Full cells consisting of gSi@C anodes and LiCoO2 cathodes are assembled and achieve good initial cycling stability with high energy density

    Performance of high strength structural bolts in tension: effects of tolerance classes

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    Structural bolts have been manufactured for building construction for hundreds of years. In practice, failure of high strength structural bolts might be caused by their tolerance classes or coating procedures, which may weaken their internal or external threads. However, this research work is dedicated to understanding a bit more on bolt performance in tension, accounting for effects of tolerance classes in the applied numerical simulation for assessment of performance of structural bolts subjected to tensile loading. In addition, different constitutive relationships has also been taken into account in the numerical analysis in use of both implicit and explicit methods. The observed simulation results demonstrated two failure mechanisms for structural bolts, threads stripping and bolt shank failure, which has proved to be associated with their tolerance classes and coating procedures applied. As a result of this, carefully selecting bolts and nuts is a deliberate solution in preventing the premature failure (threads stripping) in bolted connections for performance-based steel construction
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