2,769 research outputs found

    Diesel engine catalytic combustor system

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    A low compression turbocharged diesel engine is provided in which the turbocharger can be operated independently of the engine to power auxiliary equipment. Fuel and air are burned in a catalytic combustor to drive the turbine wheel of turbine section which is initially caused to rotate by starter motor. By opening a flapper value, compressed air from the blower section is directed to catalytic combustor when it is heated and expanded, serving to drive the turbine wheel and also to heat the catalytic element. To start, engine valve is closed, combustion is terminated in catalytic combustor, and the valve is then opened to utilize air from the blower for the air driven motor. When the engine starts, the constituents in its exhaust gas react in the catalytic element and the heat generated provides additional energy for the turbine section

    Performance of gas-lubricated cruciform-mounted tilting-pad journal bearings and a damped flexibly mounted spiral-groove thrust bearing

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    A test program was conducted to determine the performance characteristics of gas-lubricated cruciform-mounted tilting-pad journal bearings and a damped spiral-groove thrust bearing designed for the Brayton cycle rotating unit (BRU). Hydrostatic, hybrid (simultaneously hydrostatic and hydrodynamic), and hydrodynamic tests were conducted in argon gas at ambient pressure and temperature ranges representative of operation to the 10.5 kWe BRU power-generating level. Performance of the gas lubricated bearings is presented including hydrostatic gas flow rates, bearing clearances, bearing temperatures, and transient performance

    VCU\u27s My Library: Librarians Love It. . . . Users? Well, Maybe

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    Virginia Commonwealth University\u27s My Library project (circa 1998-1999) has chosen ease of use as its primary design criteria. The development of this tool using Perl scripting is described, and reports derived from usage logs are analyzed here. My Library tends to appeal a great deal to a small number of users as a personal tool. Librarians have found it popular as a class teaching tool, with pages designed for specific classes in library instruction receiving the heaviest use

    The Makings of an EP: From Silence to Portable Sounds

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    The creation of an EP is a process that requires skills in multiple areas. Once, creating an EP was only available to those who garnered resources and support from a record label. However, an increasing number of aspiring musicians are writing, recording, and making their music available for download or purchase without the assistance of a record label. Doing this successfully and excellently requires application of knowledge in areas such as literature, theology (for Christian artists), music theory, music technology, and marketing. This thesis will describe one process used to turn inspiration into a tangible product that one can purchase and play. Beginning with the process of creating songs, this explanation will explore the recording and editing process utilizing music software and equipment, and will end with the distribution of the resulting audio tracks

    Industrial laser welding: An evaluation

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    Report describes 10-kW laser welding system, designed to weld large structures made from 1/4-inch and 1/2-inch aluminum (2219) and D6AC steel

    Biases in the Experimental Annotations of Protein Function and their Effect on Our Understanding of Protein Function Space

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    The ongoing functional annotation of proteins relies upon the work of curators to capture experimental findings from scientific literature and apply them to protein sequence and structure data. However, with the increasing use of high-throughput experimental assays, a small number of experimental studies dominate the functional protein annotations collected in databases. Here we investigate just how prevalent is the "few articles -- many proteins" phenomenon. We examine the experimentally validated annotation of proteins provided by several groups in the GO Consortium, and show that the distribution of proteins per published study is exponential, with 0.14% of articles providing the source of annotations for 25% of the proteins in the UniProt-GOA compilation. Since each of the dominant articles describes the use of an assay that can find only one function or a small group of functions, this leads to substantial biases in what we know about the function of many proteins. Mass-spectrometry, microscopy and RNAi experiments dominate high throughput experiments. Consequently, the functional information derived from these experiments is mostly of the subcellular location of proteins, and of the participation of proteins in embryonic developmental pathways. For some organisms, the information provided by different studies overlap by a large amount. We also show that the information provided by high throughput experiments is less specific than those provided by low throughput experiments. Given the experimental techniques available, certain biases in protein function annotation due to high-throughput experiments are unavoidable. Knowing that these biases exist and understanding their characteristics and extent is important for database curators, developers of function annotation programs, and anyone who uses protein function annotation data to plan experiments.Comment: Accepted to PLoS Computational Biology. Press embargo applies. v4: text corrected for style and supplementary material inserte

    Baseline performance and emissions data for a single-cylinder, direct-injected diesel engine

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    Comprehensive fuel consumption, mean effective cylinder pressure, and emission test results for a supercharged, single-cylinder, direct-injected, four-stroke-cycle, diesel test engine are documented. Inlet air-to-exhaust pressure ratios were varied from 1.25 to 3.35 in order to establish the potential effects of turbocharging techniques on engine performance. Inlet air temperatures and pressures were adjusted from 34 to 107 C and from 193 to 414 kPa to determine the effects on engine performance and emissions. Engine output ranged from 300 to 2100 kPa (brake mean effective pressure) in the speed range of 1000 to 3000 rpm. Gaseous and particulate emission rates were measured. Real-time values of engine friction and pumping loop losses were measured independently and compared with motored engine values
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