12,086 research outputs found
Behavior of nozzles and acoustic liners in three-dimensional acoustic fields Quarterly report, 1 Dec. 1969 - 28 Feb. 1970
Frequency responses of supercritical nozzles and acoustic liner
Behavior of nozzles and acoustic liners in three-dimensional acoustic fields Quarterly report, 1 Sep. - 31 Dec. 1969
Theoretical studies and test facility installation for investigating behavior of rocket nozzles and acoustic liners in three dimensional acoustic field
Behavior of nozzles and acoustic liners in three-dimensional acoustic fields Quarterly report, 1 Jun. - 31 Aug. 1970
Updating computer program for determining nozzle admittances to eliminate double-root solution and to fit resultant admittance data curves by statistical mean
Behavior of nozzles and acoustic liners in three-dimensional acoustic fields Quarterly report, 1 Sep. - 31 Nov. 1970
Behavior of nozzles and acoustic liners in three dimensional acoustic field
Behavior of nozzles and acoustic liners in three-dimensional acoustic fields Quarterly report, 1 Mar. - 31 May 1969
Behavior of convergent-divergent nozzles and acoustic liners in three dimensional acoustic field
Working memory enhances target detection in the blind hemifield
Visual perception can be influenced by the content of working memory. Previous studies have shown this influence can be enough to improve unconscious visual discrimination in healthy participants and conscious visual discrimination in neuropsychological patients with extinction. Here, these findings are extended by examining the effects of holding an object in working memory on unconscious visual perception in a person with hemianopia. The results revealed significantly enhanced detection accuracy when there was an exact match between the colour and orientation of the discrimination target and the item in working memory. However, the facilitatory effect was greatly reduced when only colour or orientation was matched with the item being held in memory. A control experiment confirmed these effects were not due to visual priming. These results are consistent with the proposal that working memory guided perceptual facilitation is driven by signal enhancement. More broadly, the data are interpreted in terms of a biased competition account of visual perception
Behavior of nozzles and acoustic liners in three dimensional acoustic fields
Theoretical values of the admittances of various nozzles were computed and compared with the corresponding experimental values. The existing data reduction scheme was corrected and all available experimental data has been rechecked and corrected whenever necessary; the updated experimental admittance values are presented. An analysis associated with the frequency sensitivity of experimental admittance values was initiated and the analog-to-digital Data Reduction Program which has become operational is discussed. Fourteen nozzle tests were conducted during this report period
Optical Spectroscopy and Nebular Oxygen Abundances of the Spitzer/SINGS Galaxies
We present intermediate-resolution optical spectrophotometry of 65 galaxies
obtained in support of the Spitzer Infrared Nearby Galaxies Survey (SINGS). For
each galaxy we obtain a nuclear, circumnuclear, and semi-integrated optical
spectrum designed to coincide spatially with mid- and far-infrared spectroscopy
from the Spitzer Space Telescope. We make the reduced, spectrophotometrically
calibrated one-dimensional spectra, as well as measurements of the fluxes and
equivalent widths of the strong nebular emission lines, publically available.
We use optical emission-line ratios measured on all three spatial scales to
classify the sample into star-forming, active galactic nuclei (AGN), and
galaxies with a mixture of star formation and nuclear activity. We find that
the relative fraction of the sample classified as star-forming versus AGN is a
strong function of the integrated light enclosed by the spectroscopic aperture.
We supplement our observations with a large database of nebular emission-line
measurements of individual HII regions in the SINGS galaxies culled from the
literature. We use these ancillary data to conduct a detailed analysis of the
radial abundance gradients and average HII-region abundances of a large
fraction of the sample. We combine these results with our new integrated
spectra to estimate the central and characteristic (globally-averaged)
gas-phase oxygen abundances of all 75 SINGS galaxies. We conclude with an
in-depth discussion of the absolute uncertainty in the nebular oxygen abundance
scale.Comment: ApJS, in press; 52 emulateapj pages, 12 figures, and two appendices;
v2: final abundances revised due to minor error; conclusions unchange
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