1,721,061 research outputs found
Synthesis of hydrogen peroxide from H2 and O2 in water and ethanol catalyzed by nanoclustered Pd(0) on silica: strong selectivity enhancement exerted by the addition of ionic liquids
No full textHydrogen peroxide (H2O2) synthesis directly from dioxygen and dihydrogen was carried out using
a continuous flow reactor with a Pd catalyst. The effects of ionic liquids on the selectivity to H2O2
were studied on a Pd/SiO2 catalyst. It was found that the ionic liquid [BMIM][BF4] in water or
ethanol is quite beneficial to the selectivity to H2O2. Ca. 95% selectivity after 1 h in both solvents
and a relatively high selectivity i.e. (about 50% in ethanol and 40% in water) after 5 h reaction
have been achieved. On the other hand, a plausible mechanism for the effects of ion liquids on
this reaction system was suggested on the basis of the preliminary results
Gaining insight into the kinetics of partial oxidation of light hydrocarbons on Rh, through a multiscale methodology based on advanced experimental and modeling techniques
No full textThis chapter updates previous reviews on the catalytic partial oxidation of methane
and light hydrocarbons over noble metals; specifically, it focuses on the development
of experimental and modeling tools that in recent years allowed to measure with
accuracy and formalize the kinetics of the surface process, thus setting the basis for the
engineering of short contact time CPO reformers. Such advanced tools include special
micro-reactor designs for the kinetic investigation under isothermal conditions, first-
principle microkinetic schemes, techniques for the spatially resolved measurement of
temperature and concentration profiles inside working adiabatic reactors, detailed
reactor models accounting for the role of transport phenomena in structured catalysts
as well as that of homogeneous reactions. These contributions pave a multi-scale path,
that runs from the fundamentals of surface kinetics to the reactor optimal design
Data for: Resolving CO2 Activation and Hydrogenation Pathways over Iron Carbides from DFT Investigation
No full textCO2 activation energy; CO2 adsorption and activation over Fe_FeC; CO2 and H2 adsorption energy; PDOS_Fe5C2 and Fe3
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
Chemoselective and re-usable heterogeneous catalysts for the direct synthesis of hydrogen peroxide in the liquid phase under non-explosive conditions and in the absence of chemoselectivity enhancers.
No full textCatalyst Pd/K2621 (K2621= strongly acidic macroreticular resin from Bayer) is an effective catalyst for the direct synthesis of hydrogen peroxide in methanol at temperature near 0 C, under batch reactor conditions. Reaction conditions are non-explosive in character and no addition of selectivity enhancers is required. Selectivity up to 70% at 50% conversion is achieved
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
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