200 research outputs found

    Metallized coatings for corrosion control of Naval ship structures and components

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    In attempting to improve corrosion control, the U.S. Navy has undertaken a program of coating corrosion-susceptible shipboard components with thermally sprayed aluminum. In this report the program is reviewed in depth, including examination of processes, process controls, the nature and properties of the coatings, nondestructive examination, and possible hazards to personnel. The performance of alternative metallic coating materials is also discussed. It is concluded that thermally sprayed aluminum can provide effective long-term protection against corrosion, thereby obviating the need for chipping of rust and repainting by ship personnel. Such coatings are providing excellent protection to below-deck components such as steam valves, but improvements are needed to realize the full potential of coatings for above-deck service. Several recommendations are made regarding processes, materials, and research and development aimed at upgrading further the performance of these coatings

    Solidification behavior of high nitrogen stainless steels and establishment of a one-dimensional heat transfer framework

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    Duplex stainless steel (DSS) has excellent corrosion resistance and mechanical properties due to its dual-phase structure. The solidification process is the key to determining the structure of materials, and an in-depth investigation of solidification can help us better understand the properties of materials. The melting and solidification processes of S32101 DSS were investigated using high temperature confocal microscopy (HTCM)

    Aeronautical Engineering: A special bibliography with indexes, supplement 54

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    This bibliography lists 316 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1975

    Digitally fabricated low cost housing: material, joint and prototype

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    Motivated by the global housing deficit and limited natural resources, this study aims to utilize digital fabrication technologies coupled with local sustainable materials in the quest for alternative, adequate low-cost housing solutions for the less fortunate population, mainly in developing countries. The thesis is structured into two main parts: a theoretical and an empirical study. The theoretical part identifies the research problem and lays the foundation of knowledge, as well as defines the motivating questions, aim, objectives, scope, methodology and tools used throughout the thesis. An overview of fundamental concepts of mechanisation, standardisation, prefabrication, mass housing, and mass customisation is provided. Different types of prefabricated housing are presented followed by a discussion of select architect-led and industry-led early precedents in prefabrication. The theoretical part also includes an analysis of state-of-the-art built projects or prototypes of digitally fabricated houses. Through this analysis, how these prototypes respond to housing problems is addressed and an observation is made of how these built projects can be categorised into main streams or different trends. After defining the potentials and limitations of these precedents, a number of design criteria or design guidelines are proposed forming the basis for the proposition of a housing system that addresses these drawbacks under the name “Housing System 01”. The second part of the thesis is a Design-Build-Evaluate empirical study in which the proposed housing system combining concepts of complete off-site prefabrication with modular parametric localised digital fabrication is outlined. Given the necessity of cost reductions, an integral joining system (snap-fit) using an agricultural residue panel material is tested as the principal method for the construction of wall assemblies. The study proves that by using integral joints, it is possible to involve the end-user of the housing unit in the construction activities promoting the concept of “Self-Build”, as the simplicity of the system allows for the participation of end-users with no previous construction expertise thereby decreasing cost. A set of mechanical tests are performed to characterise wheat straw panels and then snap-fit joints are dimensioned within the elastic limits of this specific material. Three partial wall assembly prototypes are built. One axial compression test is performed on one of the prototypes. The tests show that the material and the joint system promise to provide a viable construction system as an alternative low-cost housing solution. Further optimisation and more physical structural testing are needed to address more complex forces and loading scenarios

    Engineering Principles

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    Over the last decade, there has been substantial development of welding technologies for joining advanced alloys and composites demanded by the evolving global manufacturing sector. The evolution of these welding technologies has been substantial and finds numerous applications in engineering industries. It is driven by our desire to reverse the impact of climate change and fuel consumption in several vital sectors. This book reviews the most recent developments in welding. It is organized into three sections: “Principles of Welding and Joining Technology,” “Microstructural Evolution and Residual Stress,” and “Applications of Welding and Joining.” Chapters address such topics as stresses in welding, tribology, thin-film metallurgical manufacturing processes, and mechanical manufacturing processes, as well as recent advances in welding and novel applications of these technologies for joining different materials such as titanium, aluminum, and magnesium alloys, ceramics, and plastics

    Aeronautical Engineering: A special bibliography with indexes, supplement 55

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    This bibliography lists 260 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1975

    Proceedings of a Workshop on Applications of Tethers in Space, Volume 2

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    The panel conclusions for each of the following panels (science applications; electrodynamic interactions; transportation applications; artificial gravity; constellations; and technology and test) are given

    Quality assurance program for the Carolina Crossroads Program : final

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    The South Carolina Department of Transportation (SCDOT) has developed this Quality Assurance Program (QAP) for the Carolina Crossroads (CCR) Program. This QAP utilizes contractor-performed inspection and testing in the acceptance program

    Quiet engine definition program Final report

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    Noise reduction in turbojet engines of civilian aircraf
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