1,720,961 research outputs found
Fabrication and characterization of Angled ribbon fibers using a CO2 Laser
No full textWe have produced angle at the end face of optical fibers. Repetitive experiment result illustrates its reliable and stable production of the 8 degree angle. Comparing the beam profile of regular and angled optical fibers, we confirm the
focusing of beam attributed to curvature of the angled optical fiber. Keywords—CO2 laser, ribbon fiber, 8 degree angle, CO2 lase
Femtosecond laser-assisted fabrication of microstrip patch antenna
No full textWe demonstrate a technique for fabricating microstrip patch antennas using femtosecond laser patterning followed by ultraviolet beam and chemical treatment. Initially, we design the physical parameters of both single-slot and double-slot microstrip patch antennas and simulate them using high-frequency structure simulator for optimization. Simulation results exhibit a return loss of -26 dB at the resonant frequency of 22.9 gigahertz (GHz) for single-slot microstrip patch antenna and -18.3 dB at 24.03 GHz for double-slot microstrip patch antenna. The three-dimensional polar plot and far-field radiation pattern of the microstrip patch antennas confirm excellent directivity of the antennas. Furthermore, we investigate the return loss of the fabricated microstrip patch antennas. For single-slot microstrip patch antenna, experimental result shows a return loss of -21.25 dB at 22.7 GHz. In contrast, double-slot microstrip patch antenna shows a return loss of -27 dB at 24.1 GHz. In addition, we compare the performance of the double-slot microstrip patch antenna fabricated using femtosecond laser-assisted technique and photolithographic technique and find better performance in the femtosecond laser-fabricated microstrip antenna. The proposed femtosecond laser-based technique is simple and shows promises in precise fabrication of high-quality microstrip antennas. © 2020 Society of Photo-Optical Instrumentation Engineers (SPIE).1
Characterization of femtosecond laser filamentation in soda-lime glass
No full textThis paper demonstrates the characterization of femtosecond laser filamentation in soda-lime glass. We achieved femtosecond pulse filamentation of variable height and width by focusing the femtosecond laser beam in different layers inside the sample glass. The dielectric medium immediately before the target position increases the effective numerical aperture of the objective lens that causes the elongation of focal length of the laser beam in a tiny focal spot with high power density. As a result, high aspect ratio voids are engraved inside the glass samples. Furthermore, we investigate the characteristics of the fabricated voids and their dependence on the irradiation conditions of the laser beam and associated optical setup. The height and width of the voids are controlled by varying the laser power, numerical aperture & magnification of the objective lens, and width of the dielectric medium before laser focusing position. Using high power femtosecond laser pulse filaments, we fabricated very long voids inside the glass sample, which undergoes cleaving process with uniform mechanical pressure for smooth cutting of the glass substrate
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
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
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