1,720,981 research outputs found
Fiber Optic Sensing with Lossy Mode Resonances: Applications and Perspectives
Get PDFThis review focuses on the recent advances in lossy more resonance (LMR) fiber optic sensors. LMR sensors present many interesting features also in comparison with surface plasmon resonance (SPR), the most widespread resonance-based sensing platform. Two key parameters determine the performance of LMR sensors: geometrical configuration and material supporting the LMR. After reviewing those aspects and some fundamentals of the theory, the review focuses on the sensing mechanisms, mainly based on refractometry, and their possible applications. Many examples from the literature are reported ranging from electric field to pressure sensors and from gas detection to biosensors. Such vibrant activity on LMR sensors confirms the potentiality of this technology making it a very promising platform for sensor development
Flow cell for strain- and temperature-compensated refractive index measurements by means of cascaded optical fibre long period and Bragg gratings
No full textAn optical fibre sensing system based on a hybrid cascaded long period grating (LPG) and fibre Bragg grating configuration and a thermo-stabilized flow cell for refractometric measurements is proposed. The system makes it possible to measure, and thus to cancel, the LPG cross-sensitivities to strain, temperature and fibre bending. The experimental results show that the proposed system provides satisfactory performances as far as the refractive index sensitivity and resolution are concerned. The maximum sensor sensitivity and resolution are 3120 nm/RIU and 2 × 10 -5 RIU, respectively. The whole system with its flow cell and the gratings fabrication are extensively described, together with the acquisition and data processing. The stability of the sensor for several hours was also tested. We believe that the proposed system can be successfully used for label-free chemical/biochemical sensing
A thermo-stabilized flow cell for surface plasmon resonance sensors in D-shaped plastic optical fibers
No full textThe first example of an optical sensor platform based on surface plasmon resonance (SPR) in a plastic optical fiber (POF) integrated into a thermo-stabilized flow cell for biochemical sensing applications is proposed. In this work, an IgG/anti-IgG assay was implemented as model bioassay, with the IgG biolayer deposited on the sensor gold surface and the biological target, anti-IgG, transported through a new thermo-stabilized flow cell. The experimental results show that the proposed device can be successfully used for label-free biochemical sensing. This complete optical sensor system can be used for the future reduction of the device cost and dimension, with the possibility of integrating the POF-SPR sensing platform with microfluidic and optoelectronic devices
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
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