1,720,988 research outputs found
Lasing condition for trapped modes in subwavelength-wired PT-symmetric resonators
Full text linkThe ability to control the laser modes within a subwavelength resonator is of key relevance in modern optoelectronics. This work deals with the theoretical research on optical properties of a PT-symmetric nano-scaled dimer formed by two dielectric wires, one is with loss and the other with gain, wrapped with graphene sheets. We show the existence of two non-radiating trapped modes which transform into radiating modes by increasing the gain-loss parameter. Moreover, these modes reach the lasing condition for suitable values of this parameter, a fact that makes these modes achieve an ultra high quality factor that is manifested on the response of the structure when it is excited by a plane wave. Unlike other mechanisms that transform trapped modes into radiating modes, we show that the variation of gain-loss parameter in the balanced loss-gain structure here studied leads to a variation in the phase difference between induced dipole moments on each wires, without appreciable variation in the modulus of these dipole moments. We provide an approximated method that reproduces the main results provided by the rigorous calculation. Our theoretical findings reveal the possibility to develop unconventional optical devices and structures with enhanced functionality.Fil: Cuevas, Mauro. Universidad Austral. Facultad de Ingeniería. Departamento de Ciencias Básicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Habil, Mojtaba Karimi. University Of Tabriz; IránFil: Zapata Rodríguez, Carlos Javier. Universidad de Valencia; Españ
Effect of two plant growth retardants on steviol glycosides content and antioxidant capacity in Stevia (Stevia rebaudiana Bertoni)
No full textOpposing Effects of External Gibberellin and Daminozide on Stevia Growth and Metabolites
No full textSteviol glycosides (SVglys) and gibberellins are originated from the shared biosynthesis pathway in Stevia (Stevia rebaudiana Bertoni). In this research, two experiments were conducted to study the opposing effects of external gibberellin (GA3) and Daminozide (a gibberellin inhibitor) on Stevia growth and metabolites. Results showed that GA3 significantly increased the stem length and stem dry weight in Stevia. Total soluble sugar content increased while the SVglys biosynthesis was decreased by external GA3 applying in Stevia leaves. In another experiment, the stem length was reduced by Daminozide spraying on Stevia shoots. The Daminozide did not affect the total SVglys content, while in 30 ppm concentration, significantly increased the soluble sugar production in Stevia leaves. Although the gibberellins biosynthesis pathway has previously invigorated in Stevia leaf, the Stevia response to external gibberellins implying on high precision regulation of gibberellins biosynthesis in Stevia and announces that Stevia is able to kept endogenous gibberellins in a low quantity away from SVglys production. Moreover, the assumption that the internal gibberellins were destroyed by Daminozide, lack of Daminozide effects on SVglys production suggests that gibberellins biosynthesis could not act as a competitive factor for SVglys production in Stevia leaves
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
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
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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