10,441 research outputs found

    Summary of XB-70 airplane cockpit environmental data

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    Thermal, acoustical, and acceleration environments of XB-70 airplane crew compartment in airworthiness test

    A numerical approach to controller design for the ACES facility

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    In recent years the employment of active control techniques for improving the performance of systems involving highly flexible structures has become a topic of considerable research interest. Most of these systems are quite complicated, using multiple actuators and sensors, and possessing high order models. The majority of analytical controller synthesis procedures capable of handling multivariable systems in a systematic way require considerable insight into the underlying mathematical theory to achieve a successful design. This insight is needed in selecting the proper weighting matrices or weighting functions to cast what is naturally a multiple constraint satisfaction problem into an unconstrained optimization problem. Although designers possessing considerable experience with these techniques have a feel for the proper choice of weights, others may spend a significant amount of time attempting to find an acceptable solution. Another disadvantage of such procedures is that the resulting controller has an order greater than or equal to that of the model used for the design. Of course, the order of these controllers can often be reduced, but again this requires a good understanding of the theory involved

    Review and critical analysis: Rolling-element bearings for system life and reliability

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    A ball and cylindrical roller bearing technical specification which incorporates the latest state-of-the-art advancements was prepared for the purpose of improving bearing reliability in U.S. Army aircraft. The current U.S. Army aviation bearing designs and applications, including life analyses, were analyzed. A bearing restoration and refurbishment specification was prepared to improve bearing availability

    Coal in Alaska requirements to enhance environmentally sound use in both domestic and Pacific Rim markets

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    This document originates from three meetings held in 1989 with the leaders of the Alaskan Coal Industry and coal technologists from the U.S. Department of Energy (DOE)~ Mineral Industry Research Laboratory (MIRL) and Geophysical Institute - University of Alaska Fairbanks, the Alaska Department of Natural Resources, the Alaska Science and Technology Commission, several of the Alaska Native Corporations, and a number of coal experts from private industries. The information included is intended to illustrate the vast resource base and quality of Alaskan coals, show the projected size of the Pacific Rim steam coal market, discuss policy changes necessary to facilitate the development of an expanded coal industry, and describe the technology development needs for Alaskan coals to compete in the world market. It is aimed at increasing the general knowledge about the potential of coal in Alaska and providing data for use in marketing the resource.Prepared for the Governor and Legislators - State of Alaska under the Direction of Dr. Henry Cole, Science and Technology Advisor. Technical Editor - Dr. Warrack G. Willson, Energy and Environmental Research Center, University of North Dakota; and Mineral Industry Research Laboratory, University of Alaska Fairbanks. Co-authors - W. (Bill) Irwin, Consultant, Calgary, Alberta; Dr. John Sims, Usibelli Coal Mine Inc.; Dr. p.o. Rao, Mineral Industry Research Laboratory; and Bill Noll, Suneel Alaska Corp
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