736 research outputs found

    A digital optical torquemeter for high rotational speed applications

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    A digital optical torquemeter system designed for applications at high rotational speeds was fabricated and tested for zero stability at speeds up to 20,000 rpm. Data obtained in a spin rig and with simulated inputs demonstrate that the system is capable of measuring torque bar twist to within 0.03 degrees at speeds of 30,000 rpm. The optical system uses fiber optic bundles to transmit light to the torque bar and to silicon avalanche detectors. The system is microcomputer based and provides measurements of average torque and torque as a function of angular shaft position. The torquemeter requires no bearings or other contact between the rotating torque bar and the nonrotating optics, and tolerates movement of the torque bar as large as 1 mm relative to the optics

    Optimization of fringe-type laser anemometers for turbine engine component testing

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    The fringe type laser anemometer is analyzed using the Cramer-Rao bound for the variance of the estimate of the Doppler frequency as a figure of merit. Mie scattering theory is used to calculate the Doppler signal wherein both the amplitude and phase of the scattered light are taken into account. The noise from wall scatter is calculated using the wall bidirectional reflectivity and the irradiance of the incident beams. A procedure is described to determine the optimum aperture mask for the probe volume located a given distance from a wall. The expected performance of counter type processors is also discussed in relation to the Cramer-Rao bound. Numerical examples are presented for a coaxial backscatter anemometer

    Laser anemometry for hot section applications

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    Laser anemometers (LA's) for use in the study of the hot section components of turbomachinery are being developed. Specifically, laser anemometers are being developed for use in the 50.8-cm (20-in.) diameter warm turbine and high-pressure turbine (HPT) facilities at Lewis. A brief review of the status of the program along with some preliminary data taken in an open-jet burner are presented

    Using conceptual structures in enterprise architecture to develop a new way of thinking and working for organisations

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    Enterprise Architecture (EA) is a discipline that provides generic patterns that any organisation can reuse throughout its own business, informatics and technical components. However, EA’s current way of thinking and working to achieve this aim is not standardised. EA thus continues to “reinvent the wheel” that causes mistakes or wastes resources on rediscovering what should already be known. We, therefore, represent the specific business, information and technology meta-models as patterns that can be fully reintegrated in one repeatable meta-model for the whole organisation. The outcome is a new agile way of thinking and working, highlighted by how EA works better in enterprise layers, sub-layers and levels of abstraction. To test the meta-models, two forms of Conceptual Structures known as Conceptual Graphs (CGs) and Formal Concept Analysis (FCA) are brought together through the CGtoFCA algorithm. The algorithm identifies how the layered meta-models can share meaning and truth and without having to recombine them into one large, unwieldy meta-model as the repeatable structure

    Refrigeration Lubricants - Current Practice and Future Development

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    Laser anemometers of hot-section applications

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    Laser anemometers are being developed for use in the turbine facilities at Lewis that are involved in the Turbine Engine Hot Section Technology Program. The status of the program is given along with some results accomplished since 1983

    Child and Infant Mortality; Risk Factors Related to SUID in Marion County

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    poster abstractBetween 2003- 2012, Indiana had 434 child deaths, including 53 Sudden Unexpected Infant Death (SUID) cases. Marion County has a high rate of SUID at 14%. The purpose of our research is to identify the risk factors for suffocation and to determine if SUID can be better prevented. In a pilot exploratory study, we analyzed five de-identified Marion County SUID cases to identify the asphyxia variables. The Fetal Infant Mortality Review (FIMR) cases allowed for thematic analysis. We used a meta-aggregation program NOTARI (Narrative, opinion, text assessment, and review instrument) to focus on categorical variables. Results identified asphyxia variables such as swaddling, blanket suffocation, wedging, parents bedding, soft bedding with pillows. Common maternal variables were obesity, hypertension, and STDs. Infant variables included breathing problems and cardio-respiratory pathologies. We found four cases with documented safe sleep education. The education that parents receive on safe sleep is not a guarantee that they will practice safe sleep with their infants. The education might not be effective enough to help them comprehend its importance; therefore nurses and other healthcare professionals need to consider changing the way they educate and advocate for parents. We suggest the introduction of more primary educational programs that will help the community understand safe sleep and SUID. This intervention would help decrease the incidence of sudden unexpected infant death

    Evaluating the impacts of rice-based protection dykes on floodwater dynamics in the vietnamese mekong delta using geographical impact factor (Gif)

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    This study aims at evaluating the geographical influences of rice-based protection dykes on floodwater regimes along the main rivers, namely the Mekong and the Bassac, in the Vietnamese Mekong Delta (VMD). Specifically, numerous low dykes and high dykes have been constructed particularly in the upper delta’s floodplains to protect the double and triple rice cropping against the annual flooding. For the whole deltaic domain, a 1D-quasi-2D hydrodynamic model setup was used to simulate seventy-two (72) scenarios of dyke construction development in the context of low, medium, and high floods that occurred in the VMD to examine the effects of different flood magnitudes on a certain dyke construction area. Based on the model simulation results, we established an evaluation indicator, the so-called Geographical Impact Factor (GIF), to evaluate the impacts of zone-based dyke compartments on the floodwater regimes along the main rivers for different kinds of floods. Our findings revealed different rates of influences on the floodwater levels along the Mekong and Bassac Rivers under different scenarios of zone-based high-dyke developments. GIF is a useful index for scientists and decision-makers in land use planning, especially in rice intensification, in conjunction with flood management for the VMD and for similar deltas worldwide
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