1,720,964 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Get PDF
    The 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

    Catalytic conversion of 2-chloropropane in oxidizing conditions: A FT-IR and flow reactor study

    No full text
    The conversion of 2-chloropropane (2CP) in the presence of oxygen has been investigated over a number of oxide catalysts. Mn oxide and Mn containing oxides are deactivated as combustion catalysts by chlorine, but are active in converting 2CP into propene and HCl. VWTi SCR catalysts are also very active in converting 2CP into propene, and, if vanadium content is relatively high, they also catalyse the burning of the resulting propene into CO and CO2. Acid catalysts such as alumina, silica-alumina and ZSM5 zeolite also catalyse the dehydrochlorination of CP to propene. However, HZSM5 is rapidly deactivated by coking. On silica alumina, dehydrochlorination occurs selectively at low temperature. FT-IR data and preliminary kinetic studies allowed to propose a reaction mechanism where an irreversible and fast conversion of 2CP into 2-propoxides is a key reaction step. © 2000 Elsevier Science B.V. All rights reserved

    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
    corecore