1,720,963 research outputs found
Effects of thermal annealing on the microstructure and mechanical properties of carbon-nitrogen films deposited by radio frequency-magnetron sputtering
No full textAmorphous carbon–nitrogen films deposited by radio frequency-magnetron sputtering were annealed in vacuum for 30 min at temperatures between 300 and 700 °C, without any kind of
sequential annealing. The annealing-induced modifications on the chemical composition of the films were followed by ion beam analysis ~IBA!. Raman scattering and infrared absorption spectroscopies were used to determine the microstructure modifications, while atomic force microscopy ~AFM! was used to investigate the surface morphology. The internal stress of the films was obtained by measuring the bending of the substrate and the nanoindentation technique was used to measure the
film hardness. Besides the nitrogen loss, determined by IBA analyses, Raman results suggested an increase in the size or in the number of the graphitic domains with the annealing temperature. AFM shows a decrease of the surface roughness as a function of the annealing temperature. The density, the hardness, and the internal stress of the films present a similar dependence on the annealing temperature, i.e., they increase with the temperature of the thermal treatment. The thermal treatment induces a structural modification on the carbon–nitrogen films changing from a soft paracyanogen-like material to a harder and more graphitic one
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Contrast enhancement using polarization-modulation scanning near-field optical microscopy (PM-SNOM)
No full textLacoste T, Huser T, Prioli R, Heinzelmann H. Contrast enhancement using polarization-modulation scanning near-field optical microscopy (PM-SNOM). Ultramicroscopy. 1998;71(1-4):333-340.Polarization contrast scanning near-field optical microscopy (SNOM) provides information on the orientation of molecules and molecular aggregates on surfaces. Other than in transmission or fluorescence SNOM, the control of polarization demands for SNOM probes having extinction ratios better than 20:1 in at least two perpendicular polarization directions. Most common SNOM probes consist of tapered and metal-coated fiber tips. While the birefringence of fibers can be compensated, the tapering often exhibits depolarizing effects that make good qualitative or even quantitative measurements difficult. In an attempt to improve the quality of the apertures, we have modified metal-coated fiber probes with a focused ion beam (FIB). As an example of investigations where a very good polarization control is needed, we present and discuss polarization-modulation SNOM (PM-SNOM) measurements on dye crystals. The modulation of the direction of linearly polarized light and the use of lock-in techniques allows the simultaneous detection of absorption together with magnitude and orientation of optical anisotropy. (C) 1998 Elsevier Science B.V. All rights reserved
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Comparative study of anneal-induced modifications of amorphous carbon films deposited by dc magnetron sputtering at different argon plasma pressures
No full textThis work investigates the evolution of the structural, mechanical and tribological properties of amorphous carbon films (a-C )
undergoing thermal annealing. Two different types of a-C film were studied: hard, stressed and dense films, henceforth called
‘diamond-like’, and soft, more relaxed and less dense films, called ‘polymer-like’. The two sets of films were deposited by dc
magnetron sputtering at 0.36 and 1.4 Pa argon plasma pressures, respectively, and both were annealed in vacuum for 1 h at temperatures between 300 and 700°C. Raman results provided indications of a remarkable increase of the sp2 hybridized domains,
that occurs mainly at temperatures higher than 400°C for the diamond-like films and in a continuous way for the polymer-like
films. The friction coefficient of both types of film approaches the same value with increasing temperature, whereas the surface
roughness is nearly constant. For diamond-like films, the hardness and compressive internal stress are nearly constant up to 500°C, and then undergo a fast decrease. In contrast, the hardness of the polymer-like film continuously decreases with temperature,
whereas the compressive stress remains constant
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