1,722,696 research outputs found
CCD Scan 8032: NiFe_8032
No full textCalibration data set measured at Beamline 4.0.2 of the Advanced Light Source (Berkeley, CA) using the resonant soft x-ray scattering endstation.
Scan ID: 8032
Calibration standard with 200-nm X 200-nm pitc
The WC10 central stars CPD-56 degrees 8032 and He 2-113 .1. Distances and nebular parameters
Full text linkWe present the results of an analysis of the WC10 central stars CPD −56°8032 and He 2-113 and of their surrounding planetary nebulae (PNe). UCL Echelle Spectrograph spectra with a resolving power of R = 50 000, covering the wavelength range 3600–9500 Å, were obtained for both objects.
Expansion and radial velocities are derived from the nebular Balmer lines. Reddenings were derived from the observed Hα/Hβ decrements, as well as from the ratio of the radio free-free and Hβ fluxes. We find that E(B—V) = 0.68 for CPD−56°8032 and 1.00 for He 2-113. The bolometric luminosity is found to be 2820 D2 (kpc) L⊙ for CPD — 56°8032 and 2290 D2 (kpc) L⊙ for He 2-113. We have used a calibration based on Magellanic Cloud Wolf-Rayet central stars to estimate a distance of 1.35 kpc to CPD — 56°8032 and 1.50 kpc to He 2-113. A comparison of the radial velocities of interstellar Na I D-line absorption components with Galactic rotation curve predictions for each line of sight yields distances which agree within the uncertainties with these values.
We also present deconvolved pre-COSTAR HST Hβ images, from which we derive nebular angular sizes of 1.6 × 2.1 arcsec2 for CPD—56°8032 and 1.4 × 1.1 arcsec2 for He 2-113. From our spectra, nebular electron temperatures of 8800 and 8400 K are derived for CPD. 56°8032 and He 2-113 respectively, while an electron density of 6 × 104 cm−3 is determined for both nebulae. Sulphur is found to have a near-solar abundance in both nebulae, and the nebular nitrogen abundances are also close to solar. The nebular C/O abundance ratios (determined with the help of low-resolution IUE spectra) are found to be equal to 13 for CPD. 56°8032 and 10 for He 2-113, respectively, significantly higher than the values normally found for Galactic PNe. We find no detectable amounts of hydrogen in either stellar wind
[Chicago & North Western Rwy., Engine Drawing Card, Sketch No. 8032]
No full textThis engine drawing card was created for Chicago and North Western Railway Company, Class 16-48 2/4 E. Section N-16 2/4 E. Sketch 8032. Copy Spec. Co's spec. Class H. Loco Nov 3-1929 Based on Sk. 8014
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Discovery of an Edge-on Dust Disk around the [WC10] Central Star CPD –56°8032
Full text linkWe present Hubble Space Telescope ultraviolet and optical Space Telescope Imaging Spectrograph spectroscopy of the [WCL] planetary nebula central star CPD -56°8032, obtained during its latest light-curve minimum. The UV spectrum shows the central star's continuum light distribution to be split into two bright peaks separated by 0farcs10. We interpret this finding as due to an edge-on disk or torus structure that obscures direct light from the star, which is seen primarily via its light scattered from the disk's rims or lobes. CPD -56°8032 is an archetype of dual dust chemistry [WCL] planetary nebulae, which exhibit strong infrared emission features from both carbon-rich and oxygen-rich materials, and for which the presence of a disk harboring the O-rich grains had been suggested. Our direct observation of an edge-on occulting dust structure around CPD -56°8032 provides strong support for such a model and for binary interactions being responsible for the correlation between the dual dust chemistry phenomenon in planetary nebulae and the presence of a hydrogen-deficient [WCL] Wolf-Rayet central star
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
