1,722,013 research outputs found
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
Iron-Catalyzed Amidation of Aldehydes with N-Chloroamines
No full textA new direct conversion of aldehydes to amides has been realized, in the presence of iron(III) chloride as a catalyst and using tert-butyl hydroperoxide (TBHP) as an oxidant. Both aliphatic and aromatic aldehydes were successfully reacted with variously mono- and di-substituted N-chloroamines. The methodology has a wide substrate scope, uses cheap and easily available reagents and is characterized by short reaction times
Numerical and experimental frequency response of plasma synthetic jet actuators
No full textPlasma synthetic jet (PSJ), or Sparkjet, actuators seem to be a promising technology to improve the aircraft performances due to their short response time, high jet velocities and absence of moving parts. This paper aims at presenting a combined numerical and experimental investigation, to obtain information about the frequency response of the device. From the numerical point of view, an innovative lumped-element model (LEM), able to predict the temporal evolution of the main fluid-dynamic variables of the device, is presented. It is fully based on the gasdynamics equations, it includes viscous losses as well as radiative and convective heat transfer mechanisms at walls, and it considers the air as a real gas. OpenFOAM numerical computations have been carried out to perform a first calibration of the lumped model through the determination of key fitting parameters. Results for both single pulse mode and repetitive working regimes are reported, providing insights on the major actuation characteristics. To validate the model, a home-designed actuator has been manufactured, together with the control electric circuit. Experimental measurements of the jet velocity complete the actuator characterization and the model validation
Critical Surveys Covering The Year 2012: Introduction and Trasformation of Functional Groups: H-Borrowing and H-Transfer Reactions
No full text
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
- …
