1,721,092 research outputs found
Assessment and management of new and emerging risks for Europe's dietary supplement companies operating with botanicals
No full textThis study identifies new and emerging risks in the botanicals sector with the aim of fostering the success of nutraceutical and dietary supplement companies based on quality, product safety, and consumer trust. Focusing on the Italian nutraceutical market, an analysis was conducted based on interviews with experts. The outcomes of the analysis and the resulting guidelines on how to manage safety and quality by preventing risk at firms commercializing botanical-based nutraceuticals and dietary supplements are of direct relevance to industry practitioners and to bioeconomy and biotechnology scholars. © 2020 Society of Industrial Chemistry and John Wiley & Sons Ltd
Fluorinated Silica Gels Doped with TPAP as Effective Aerobic Oxidation Catalysts in Dense Phase Carbon Dioxide
No full textAbstract: Hybrid organic-inorganic fluorinated silica glasses doped with the ruthenium species TPAP (tetra-n-propylammonium perruthenate) are effective catalysts for the aerial oxidation of benzyl alcohol to benzaldehyde in dense phase CO2. Moderate silica fluorination (10%) by short-chain fluoroalkyl-containing monomers in the sol-gel polycondensation with TMOS affords highly active catalysts which at 75 oC and 220 bar selectively dehydrogenate the alcohol with oxygen as primary oxidant. Both the activity and the stability of the fluorinated materials vary with the degree of fluorination and the nature of the fluoroalkyl residue attached to the silica polymeric network. An explanation of the behaviour of doped sol-gel oxides in supercritical carbon dioxide is proposed which is thought to be of general validity for future practical applications to heterogeneously catalysed aerobic oxidations eliminating the current need for both organic solvents and stoichiometric oxidants
FluoRuGel: a versatile catalyst for aerobic alcohol oxidation in supercritical carbon dioxide
No full textA comparative analysis between metal-based aerobic catalysts shows that FluoRuGel, an hybrid fluorinated silica solgel
glass doped with the ruthenium species TPAP (tetra-n-propylammonium perruthenate), is a competitive catalyst for
the aerial oxidation of alcohols. In particular, the FluoRuGel/O2 system is well suited for carrying out convenient
oxidative dehydrogenations in dense phase CO2 smoothly affording high yields of a variety of structurally different
aldehydes and ketones of high purity. The potential rewards of this new technology are numerous and go beyond simple
elimination of both organic solvents and stoichiometric oxidants employed in traditional alcohol oxidations
Omeg@Silica: Entrapment and Stabilization of Sustainably Sourced Fish Oil
Full text linkFish oil rich in long-chain polyunsaturated fatty acids, vitamin D-3 and carotenoid pigments have been sustainably extracted from anchovy fillet leftovers using biobased limonene. The oil is conveniently stabilized by adsorption on periodic mesoporous silicas. The simplicity of the process, the high load of fish oil, and the biocompatible nature of mesoporous silica support numerous forthcoming applications of this new class of "Omeg@Silica" materials
Ru-based Oxidation Catalysis
No full textRanging from the oxidative conversion of water to O2 to the elegant hydroxylation of olefins and to oxidative
dehydrogenation of alcohols Ru-mediated oxidations are finding increasing application due to the unique properties of
this extremely versatile transition metal, whose oxidation state can vary from –II to +VIII. Covering recent
developments in both homogeneously and heterogeneously catalysed oxidations (in liquid-phase as well as in novel
reaction media), this tutorial review aims to provide investigators with a general picture of the chemical and structural
origins of the excellent performance of many ruthenium catalysts and to promote further advancements that, it is
envisaged, will soon benefit society at large
The Effects of Material Properties on the Activity of Sol-gel Entrapped Perruthenate under Supercritical Conditions
No full textSilica gels organically modified and doped with the ruthenium species tetra-n-propylammonium perruthenate (TPAP) are leach-proof, selective catalysts for the aerobic oxidation of alcohols to carbonyl compounds with dioxygen at low pressure in compressed carbon dioxide. The catalytic sol-gels are recyclable and the correlation between the reactivity of the materials and their surface polarity and textural properties suggests valuable information on the chemical behaviour of sol-gel entrapped silica catalysts in oxidation catalysis which is of relevant interest considering the importance of heterogeneous oxidative dehydrogenation of alcohols in fine chemistry. An explanation of the structure-activity relationship is proposed to provide guidelines for the further development of efficient solid oxidation catalysts for conversions in supercritical carbon dioxide
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
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
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