42 research outputs found
Activation and Deactivation of a Robust Immobilized Cp*Ir-Transfer Hydrogenation Catalyst: A Multielement in Situ X-ray Absorption Spectroscopy Study
A highly robust immobilized [Cp*IrCl2]2 precatalyst on Wang resin for transfer hydrogenation, which can be recycled up to 30 times, was studied using a novel combination of X-ray absorption spectroscopy (XAS) at Ir L3-edge, Cl K-edge, and K K-edge. These culminate in in situ XAS experiments that link structural changes of the Ir complex with its catalytic activity and its deactivation. Mercury poisoning and âhot filtrationâ experiments ruled out leached Ir as the active catalyst. Spectroscopic evidence indicates the exchange of one chloride ligand with an alkoxide to generate the active precatalyst. The exchange of the second chloride ligand, however, leads to a potassium alkoxideâiridate species as the deactivated form of this immobilized catalyst. These findings could be widely applicable to the many homogeneous transfer hydrogenation catalysts with Cp*IrCl substructure
Parùmetros psicométricos: uma anålise de testes psicológicos comercializados no Brasil
Conceptual blending and musical emotion
The scholarly literature on conceptual blending and emotion is very scant. One exception is a short section in Fauconnier and Turner (2002) focused on the emotion of anger. Fauconnier and Turner refer to the cross-cultural research of Lakoff and Kövecses (1987) on the anger script. The present article takes this dialogue on anger as a starting point to develop two separate yet interlinked matters: first, to open up a perspective on emotion from the standpoint of conceptual blending; second, to apply this perspective to the analysis of musicâs structural features. The article begins by reviewing Juslin and Timmersâ (2010) model of the expressive character of acoustic features and proceeds to assess Lakoff and Kövecsesâ theory of emotion as cognitive metaphor. Reconciling the cognitive metaphor of anger with the theory of conceptual blending allows us to analyze anger in two pieces, by Vivaldi and Haydn, respectively. The analysis throws into relief issues which arise when we apply conceptual blending to aesthetic objects in general, and musical works in particular. One key concept here is Fauconnier and Turnerâs notion of time compression. Finally, the article examines Brandtâs (2006) useful ideas on blending in art as a way of further clarifying the special status of emotion in music, as distinct from utilitarian emotion in everyday life. The article concludes that a synthesis of conceptual blending and cognitive metaphor provides a useful tool for analyzing musical emotion
Criteria definition and approaches in green supplier selection â a case study for raw material and packaging of food industry
Surface structural-chemical characterization of a single-site d0 heterogeneous arene hydrogenation catalyst having 100% active sites
Dispensing quails, mincemeat, leaven: Katherine Parr's patronage of the paraphrases of Erasmus
As a prominent patron of humanist scholarship and Reformed religion, and the author of several devotional works in her own right, Katherine Parr exerted a significant influence on the English Reformation â as several scholars have begun to explore. Yet to date, it is the texts that most legibly bear her authorial signature that have attracted critical attention. Parrâs patronage, by contrast, has long been widely celebrated as historical fact and at the same time surprisingly ignored as a social, literary and mechanical process. In the Acts and Monuments (1563), for instance, John Foxe paints a triumphal Protestant portrait of the queen as the periodâs âonly patroness of the professors of the truthâ. And Parrâs recent biographer Susan James goes so far as to say that Katherine was âby conviction, by influence and by actions the first true queen of the English Reformationâ. According to James Kelsey McConicaâs 1965 portrayal of the period, Parrâs generation: "found appropriate patronage, not in a Machiavellian Secretary of State, but in a noble lady of irenic temperament and sincere attachment to humanist learning. ... It is in her circle, which revives the traditions of her royal predecessors Margaret Beaufort and Catherine of Aragon, that the Erasmian spirit finds new shelter and influential support.