57,875 research outputs found

    Feasibility of Thermosyphons to Impede the Progress of Coastal Permafrost Erosion Along the Norther Coastline of Alaska

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    Presented to the Faculty of the University of Alaska Anchorage in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCEThis study seeks to investigate the feasibility of installing thermosyphons at Drew Point, Alaska to mitigate thermally-induced coastline erosion. Portions of the northern Alaska coastline have been receding at increasing rates and putting in peril infrastructure, environmental habitats, and small villages. Slowing or eliminating the erosion would prevent emotional village relocations and costly infrastructure maintenance and relocations. Climate and soil data from Drew Point and Barrow, Alaska are used as input variables in a numerical modeling software program to determine accurate soil thermal properties to be used in a thermosyphon design. Generalized cost considerations are presented and it is determined that thermosyphons may be an effective mitigation strategy to combat coastal erosion, however, future additional modeling could optimize a design and provide for refinements in the cost analysis.Abstract / Table of Contents / List of Figures / List of Tables / Acknowledgements / Introduction and Background / Objective and Methodology / Data Collection and Climate Analysis / Modeling / Heat Transfer Analysis / Thermosyphon Design / Discussion / Conclusion / Reference

    Structural validation of a realistic wing structure: the RIBES test article

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    Several experimental test cases are available in literature to study and validate fluid structure interaction methods. They, however, focus the attention mainly on replicating typical cruising aerodynamic conditions forcing the adoption of fully steel made models able to operate with the high loads generated in high speed facilities. This translates in a complete loss of similitude with typical realistic aeronautical wing structures configurations. To reverse this trend, and to better study the aerolastic mechanism from a structural point of view, an aeroelastic measurement campaign was carried within the EU RIBES project. A half wing model for wind tunnel tests was designed and manufactured replicating a typical metallic wing box structure, producing a database of loads, pressure, stress and deformation measurements. In this paper the design, manufacturing and validation activities performed within the RIBES project are described, with a focus on the structural behavior of the test article. All experimental data and numerical models are made freely available to the scientific community

    Advanced flight control system study

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    A fly by wire flight control system architecture designed for high reliability includes spare sensor and computer elements to permit safe dispatch with failed elements, thereby reducing unscheduled maintenance. A methodology capable of demonstrating that the architecture does achieve the predicted performance characteristics consists of a hierarchy of activities ranging from analytical calculations of system reliability and formal methods of software verification to iron bird testing followed by flight evaluation. Interfacing this architecture to the Lockheed S-3A aircraft for flight test is discussed. This testbed vehicle can be expanded to support flight experiments in advanced aerodynamics, electromechanical actuators, secondary power systems, flight management, new displays, and air traffic control concepts

    A Classification and Survey of Computer System Performance Evaluation Techniques

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    Classification and survey of computer system performance evaluation technique
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