1,721,012 research outputs found
Undulatory theory of phonons on the nanofluid thermal conduction
No full textThe present paper proposes a theoretical model for the prediction of the specific heat capacity and conductivity of nanofluids. The main control parameters of the model are sound velocity and thermal expansion coefficient of liquid and solid phases. The model also includes the thickness of the liquid wrapping the particles, in which it is relevant the thermal diffusion. Theoretical predictions were tested against the experimental data about the heat transfer in a nanofluid made by aluminum oxide nanoparticles, stably suspended in tap water. Thermal conductivity and heat capacity linearly change as function of the nanoparticle concentration. The molecular boundary layer develops towards the nanoparticle with the thermal expansion coefficient that changes linearly from zero at the particle surface up to the bulk value. The specific heat capacity does not have relevant effects due to the temperature variations. The temperature increasing induces a slight enhancement of the thermal conductivity because of the base fluid contribution
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
- …
