6,164 research outputs found

    Mark 3 real-time fringe detection system

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    A RAM memory built into the Mark 3 decoder module allows the capture of 1 Megabit of data. Data may be collected either in real time or from a pre-recorded tape. Once collected, the data may be retrieved using a standard EIA serial data link. The data may be transmitted to a remote computer for cross correlation processing with similar data from other stations to verify fringes in real time. The data may also be analyzed by a local computer to verify phase calibration, bandpass, format, etc., during a Mark 3 observing session

    Analytical and Experimental Study of Flow Through an Axial Turbine Stage with a Nonuniform Inlet Radial Temperature Profile

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    Results are presented for a typical nonuniform inlet radial temperature profile through an advanced single-stage axial turbine and compared with the results obtained for a uniform profile. Gas temperature rises of 40 K to 95 K are predicted at the hub and tip corners at the trailing edges of the pressure surfaces in both the stator and rotor due to convection of hot fluid from the mean by the secondary flow. The inlet temperature profile is shown to be mixed out at the rotor exit survey plane (2.3 axial chords downstream of the rotor trailing edge) in both the analysis and the experiment. The experimental rotor exit angle profile for the nonuniform inlet temperature profile indicates underturning at the tip caused by increased clearance. Severe underturning also occurs at the mean, both with and without the nonuniform inlet temperature profile. The inviscid rotational flow code used in the analysis fails to predict the underturning at the mean, which may be caused by viscous effects

    Description of the warm core turbine facility recently installed at NASA Lewis Research Center

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    The two net facilities were installed and operated at their design, or rated conditions. The important feature of both of these facilities is that the ratio of turbine inlet temperature to coolant temperature encountered in high temperature engines can be duplicated at moderate turbine inlet temperature. The limits of the facilities with regard to maximum temperature, maximum pressure, maximum mass flow rate, turbine size, and dynamometer torque-speed characteristics are discussed

    Performance of a high-work low aspect ration turbine tested with a realistic inlet radial temperature profile

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    Experimental results are presented for a 0.767 scale model of the first stage of a two-stage turbine designed for a high by-pass ratio engine. The turbine was tested with both uniform inlet conditions and with an inlet radial temperature profile simulating engine conditions. The inlet temperature profile was essentially mixed-out in the rotor. There was also substantial underturning of the exit flow at the mean diameter. Both of these effects were attributed to strong secondary flows in the rotor blading. There were no significant differences in the stage performance with either inlet condition when differences in tip clearance were considered. Performance was very close to design intent in both cases

    A Massive Protostar Embedded in the Scuba Core JCMT 18354-0649S

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    We report the discovery of an extremely red object embedded in the massive SCUBA core JCMT 18354-0649S. This object is not associated with any known radio or far-IR source, though it appears in Spitzer IRAC data obtained as part of the GLIMPSE survey. At shorter wavelengths, this embedded source exhibits an extreme color, K – L' = 6.7. At an assumed distance of 5.7 kpc, this source has a near-IR luminosity of ~1000 L_☉. Its spectral energy distribution (SED) rises sharply from 2.1 μm to 8 μm, similar to that of a Class 0 young stellar object. Theoretical modeling of the SED indicates that the central star has a mass of 6-12 M_☉, with an optical extinction of more than 30. As both inflow and outflow motions are present in JCMT 18354-0649S, we suggest that this deeply embedded source is (1) a massive protostar in the early stages of accretion, and (2) the driving source of a massive molecular outflow evident in HCN J = 3-2 profiles observed toward this region

    Applied regional monitoring of the vernal advancement and retrogradation (Green wave effect) of natural vegetation in the Great Plains corridor

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    The author has identified the following significant results. LANDSAT 2 has shown that digital data products can be effectively employed on a regional basis to monitor changes in vegetation conditions. The TV16 was successfully applied to an extended test site and the Great Plains Corridor in tests of the ability to assess green forage biomass on rangelands as an index to vegetation condition. A strategy for using TV16 on a regional basis was developed and tested. These studies have shown that: (1) for rangelands with good vegetative cover, such as most of the Great Plains, and which are not heavily infested with brush or undesirable weed species, the LANDSAT digital data can provide a good estimate (within 250 kg/ha) of the quantity of green forage biomass, and (2) at least five levels of pasture and range feed conditions can be adequately mapped for extended regions

    Student Development During the Occupy SLU Movement Through the Lens of Perry

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    Perry’s theory of intellectual and ethical development serves as a seminal theory on student development. The civil unrest in Ferguson, Missouri during the 2014-2015 school year resulted in demonstrations on college campuses throughout the country, including the Occupy SLU movement at Saint Louis University. In this mixed-methods phenomenological study, 19 students were interviewed about their experiences during the movement. The research questions underlying this study include: How were SLU students impacted by the events in Ferguson, Missouri during the 2014-2015 school year? How can Perry’s theory be applied to student development during this historic time? How can these findings be utilized to better understand and support student development during periods of civil unrest? The participants’ stories are analyzed through the lens of Perry’s theory using the constant comparative method. Evidence of Perry’s four stages of development emerged from the data, including dualism, multiplicity, relativism, and commitment to relativism, as well as evidence of his three deflections from growth, including temporizing, escape, and retreat. The findings of this research serve to capture the student experiences on campus during Occupy SLU, inform higher education professionals on the impact of this social movement, and provide further validation for Perry’s theory

    Recovery of immune competence after tumour resection in mice: correlation with loss of suppressor elements.

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    Changes in the immune competence and levels of suppressore elements were assessed by mitogen stimulation and in vitro antibody production, after resection of a transplantable sarcoma. Spleen cells from tumour-resected animals were found to have depressed responses to conA as well as to the antigens SRBC and DNP-LPS. This inability to respond was gradually overcome and, by Day 21 after resection, spleen cell competence had returned to normal levels. Suppressor cells isolated from the spleens of tumour-resected animals were capable of suppressing the conA response and PFC response of normal syngeneic spleen cells in vitro. The ability to suppress the conA response of normal cells disappeared by Day 1 after resection, while the ability to suppress the anti-SRBC and anti-DNP PFC response of normal cells disappeared by Day 8 and Day 14 respectively. Serum from tumour-resected mice was also found to be suppressive to the conA response of normal spleen cells. The inhibitory material responsible for suppression eluted with the Ig-containing fraction on Sephadex G-150. This inhibitory material gradually disappeared from the serum of tumour-resected mice and was no longer apparent by Day 14. Therefore, it appeared that the return of normal lymphocyte function after tumour-resection was concomitant with the disappearance of splenic suppressor cells and suppressive serum factor
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