987 research outputs found

    Mechanical Engineering: Prospectus for Day and Evening Classes 1951-52

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    Courses and timetables for the College of Technology, Bolton Street, Dublin 1

    Mechanical Engineering: Prospectus for Day and Evening Classes 1950-51

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    Courses and timetables for the College of Technology, Bolton Street, Dublin 1

    Thermal management system architecture for hydrogen-powered propulsion technologies: practices, thematic clusters, system architectures, future challenges, and opportunities

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    The thermal management system architectures proposed for hydrogen-powered propulsion technologies are critically reviewed and assessed. The objectives of this paper are to determine the system-level shortcomings and to recognise the remaining challenges and research questions that need to be sorted out in order to enable this disruptive technology to be utilised by propulsion system manufacturers. Initially, a scientometrics based co-word analysis is conducted to identify the milestones for the literature review as well as to illustrate the connections between relevant ideas by considering the patterns of co-occurrence of words. Then, a historical review of the proposed embodiments and concepts dating back to 1995 is followed. Next, feasible thermal management system architectures are classified into three distinct classes and its components are discussed. These architectures are further extended and adapted for the application of hydrogen-powered fuel cells in aviation. This climaxes with the assessment of the available evidence to verify the reasons why no hydrogen-powered propulsion thermal management system architecture has yet been approved for commercial production. Finally, the remaining research challenges are identified through a systematic examination of the critical areas in thermal management systems for application to hydrogen-powered air vehicles’ engine cooling. The proposed solutions are discussed from weight, cost, complexity, and impact points of view by a system-level assessment of the critical areas in the field

    Utilization of diesel engine in harbour marine crafts

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    Investigations of the Tribological Effects of Engine Oil Dilution by Vegetable and Animal Fat Feedstock Biodiesel on Selected Surfaces

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    Biodiesels have become attractive alternative fuel to replace traditional fossil fuels. Biodiesels can be used in diesel engines with no major modification, but its use leads to some degree of engine oil dilution because of biodiesel leaking and scrapping to engine oil pan. Biodiesels can be made from vegetable and animal fat feedstocks. Therefore, the fatty acid methyl ester components of biodiesel may vary upon these sources of feedstock. In this thesis work, engine oil is diluted with vegetable (canola oil, peanut oil and soybean oil biodiesel) and animal (chicken fat) feedstock biodiesels at known percentages and these mixtures are tested in a pinon-disk tribometer. In-process friction force and temperature changes are observed and specific wear on the tested surface and dilution effects on viscosity are measured. The oxidative stability of diluted engine oils is also assessed by observation. Experimental results suggest that a higher fraction of palmitic and a lower fraction of linoleic acid contents of the biodiesel play a role for providing good lubricity when mixed with the engine oil in the tested condition and animal feedstock biodiesel perform better than that of vegetable feedstock biodiesel

    Index to 1984 NASA Tech Briefs, volume 9, numbers 1-4

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    Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1984 Tech B Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

    Aeronautical Engineering. A continuing bibliography, supplement 112

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    This bibliography lists 424 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1979

    NASA patent abstracts bibliography: A continuing bibliography. Section 1: Abstracts (supplement 18)

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    Abstracts are cited for 120 patents and patent applications for patents introduced into the NASA scientific system during the period of July 1980 through December 1980. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or application for patent

    Comparison of Four Numerical Methods of EHL Modeling

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    Near term hybrid passenger vehicle development program, phase 1

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    Missions for hybrid vehicles that promise to yield high petroleum impact were identified and a preliminary design, was developed that satisfies the mission requirements and performance specifications. Technologies that are critical to successful vehicle design, development and fabrication were determined. Trade-off studies to maximize fuel savings were used to develop initial design specifications of the near term hybrid vehicle. Various designs were "driven" through detailed computer simulations which calculate the petroleum consumption in standard driving cycles, the petroleum and electricity consumptions over the specified missions, and the vehicle's life cycle costs over a 10 year vehicle lifetime. Particular attention was given to the selection of the electric motor, heat engine, drivetrain, battery pack and control system. The preliminary design reflects a modified current compact car powered by a currently available turbocharged diesel engine and a 24 kW (peak) compound dc electric motor
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