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  • Other Sources  (8)
  • 1985-1989  (7)
  • 1965-1969  (1)
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  • 1
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    Flow in out-of-plane double S-bonds (1986)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Developing flows in two out-of-plane double S-bend configurations have been measured by laser-Doppler anemometry. The first duct had a rectangular cross-section 40mmx40mm at the inlet and consisted of a uniform area 22.5 deg. - 22.5 deg. S-duct upstream with a 22.5 deg.- 22.5 deg. S- diffuser downstream. The second duct had a circular cross-section and consisted of a 45 deg. - 45 deg. uniform area S-duct upstream with a 22.5 deg. -22.5 deg. S-diffuser downstream. In both configurations the ratio of the mean radius of curvature to the inlet hydraulic diameter was 7.0, the exit-to-inlet area ratio of the diffusers was 1.5 and the ducts were connected so that the centerline of the S-duct lay in a plane normal to that of the S-diffuser. Streamwise and cross-stream velocity components were measured in laminar flow for the rectangular duct and in turbulent flow for both configurations; measurements of the turbulence levels, cross-correlations and wall static pressures were also made in the turbulent flow cases. Secondary flows of the first kind are present in the first S-duct and they are complemented or counteracted by the secondary flows generated by the area expansion and by the curvature of the S-diffusers downstream. Cross-stream velocities with magnitudes up to 0.19 and 0.11 of the bulk velocity were measured in the laminar and turbulent flows respectively in the rectangular duct and six cross-flow vortices were evident at the exit of the duct in both flow cases. The turbulent flow in the circular duct was qualitatively similar to that in the rectangular configuration, but the cross-stream velocities measured at the exit plane were smaller in the circular geometry. The results are presented in sufficient detail and accuracy for the assessment of numerical calculation methods and are listed in tabular form for this purpose.
    Keywords: FLUID MECHANICS AND HEAT TRANSFER
    Type: NASA-CR-176981 , NAS 1.26:176981 , FS/86/30
    Format: application/pdf
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  • 2
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    On the nature of Ryle and Bailey's candidate star for the pulsating radio source CP 1919. (1969)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Photoelectric monitoring broadband photometry and spectral scans of candidate star for pulsating radio source CP 1919
    Keywords: SPACE SCIENCES
    Type: ; RO(
    Format: text
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  • 3
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    Flow in out-of-plane double S-bends (1987)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: An experimental investigation of developing flows through a combination of out-of-plane S-bend ducts was conducted to gain insight into the redirection of flow in geometries similar to those encountered in practical aircraft wing-root intake ducts. The present double S-bend was fabricated by placing previously investigated S-ducts and S-diffusers in series and with perpendicular planes of symmetry. Laser-Doppler anemometry was employed to measure the three components of mean velocity, the corresponding rms quantities, and Reynolds stresses in the rectangular cross-section ducts. Due to limited optical access, only two mean and rms velocity components were resolved in the circular cross-section ducts. The velocity measurements were complemented by wall static pressure measurements. The data indicates that the flows at the exit are complex and asymmetric. Secondary flows generated by the pressure field in the first S-duct are complemented or counteracted by the secondary flows produced by the area expansion and the curvature of the S-diffuser. The results indicate the dominance of the inlet conditions and geometry upon the development of secondary flows and demonstrate that the flows are predominantly pressure-controlled. The pressure distribution caused by the duct geometry determines the direction and magnitude of the bulk flow while the turbulence dictates the mixing characteristics and profiles in the near wall region.
    Keywords: AERODYNAMICS
    Type: Symposium on Turbulent Shear Flows; Sept. 7-9, 1987; Toulouse; France
    Format: text
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  • 4
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    High-resolution CCD imaging and derived gravitational lens models of 2237+0305 (1988)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: Images of the gravitational lens 2237+0305 acquired in good seeing have resolved the system into at least five components within the central few arsec of the object: the galaxy nucleus and four point sources in a ringlike formation approximately centered on the galaxy. It is found that the four point sources are distinctly bluer than the galaxy, but that they do not have identical colors. The observed configuration is well reproduced by a simple model that assumes that the four objects are images of the quasar and that the lens is a constant mass-to-light ratio, elliptical, de Vaucouleurs bulge.
    Keywords: ASTROPHYSICS
    Type: Astronomical Journal (ISSN 0004-6256); 95; 1619-162
    Format: text
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  • 5
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    Spectroscopy of the extranuclear line-emitting regions associated with the gravitational lens system 2016 + 112 (1987)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: Moderate-resolution slit spectroscopy of the extended emission-line objects A1 and B1 located within 5 arcsec of the triple radio source 2016 + 112 shows that at least one is physically associated with the z = 3.273 quasar thought to be multiply imaged by a foreground galaxy. The data and theoretical models unanimously favor the identification of A1 and B1 with two separate clouds of ionized gas that lie within a few kiloparsecs of the primary A/B QSO and radio source. The available evidence does not support the view that they are multiple images of a single object or their classification as separate (companion) galaxies.
    Keywords: ASTROPHYSICS
    Type: Astronomical Journal (ISSN 0004-6256); 94; 12-15
    Format: text
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  • 6
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    Optical observations of SN 1987D in UGC 7370 (1987)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: This paper presents optical photometry and spectroscopy of SN 1987D, a Type Ia supernova in the nearby galaxy UGC 7370, during the period immediately subsequent to its discovery. The distance modulus of the galaxy, independently determined by the redshift and the Tully-Fisher (1977) relation, is 32.3 + or - 1.0. The maximum brightness of SN 1987D was V about 13.2 and occurred on April 18, 1987, + or - 4 days; the absolute luminosity is about 0.6 mag brighter than the average for SNe Ia. The spectrum of SN 1987D is typical of SNe Ia, but the expansion velocity (9600 km/s) is considerably lower than average.
    Keywords: ASTRONOMY
    Type: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 99; 1167-117
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  • 7
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    Spectroscopic CCD surveys for quasars at large redshift. I - A deep PFUEI survey (1986)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: A survey for faint quasars has been conducted using slitless spectroscopy with the PFUEI at the 200 inch (5 m) telescope. The survey covers a total of 0.91 sq deg in 113 fields at galactic latitudes above 30 deg. Calibrated spectra in the range 4500-7200 A were obtained for more than 9000 objects. Emission-line candidates were selected on the basis of two criteria: the equivalent width must exceed 50 A, and the signal-to-noise ratio of the detection of the line versus the sky background should be larger than 7. Among 45 candidates so selected, subsequent slit spectroscopy confirmed 27 emission-line objects. Among these, 17 are emission-line galaxies with redshifts in the range 0.04-0.31, and 10 are quasars with redshifts between 0.91 and 2.66. The well-defined selection criteria for these objects, together with the distribution of rest frame equivalent widths of the emission lines, allow derivation of the area of sky covered as a function of the continuum limiting magnitude. The observed number of quasars in the redshift range 0.7-2.7 agrees well with that predicted by the luminosity function models published by Schmidt and Green in 1983. It is concluded that quasars with an absolute magnitude of M(B) = -25 suffer a redshift cutoff near or below a redshift of 3.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 306; 411-427
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  • 8
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    X-ray observations of the bright quasar survey (1986)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: Using the Einstein Observatory, X-ray observations of about 80 percent of the quasars in the Bright Quasar Survey located outside the declination range defined by 30 and 60 deg. X-ray emission has been detected above the 3-sigma level for 57 out of 66 quasars observed. This paper describes observations and data reduction and provides a summary of the more detailed analyses and discussion contained in the two accompanying papers (Schmidt and Green 1986, Avni and Tananbaum 1986).
    Keywords: ASTRONOMY
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 305; 57-67
    Format: text
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