1,721,186 research outputs found
Miglioramento dell’Efficienza Aerodinamica tramite Interventi di Scavo sul Fondo Vettura
No full textReport of Depart. of Aerospace Eng. of Pisa, DDIA 2006-05, July 200
Miglioramento dell’efficienza aerodinamica attraverso l’introduzione di minigonne sul fondo vettura
No full textReport of Depart. of Aerospace Eng. of Pisa, DDIA 2006-15, Oct. 2006
Is a Catalyst Always Needed? The Case of the Knoevenagel Reaction with Malononitrile
No full textThe aim of this Perspective is to start a discussion about the real usefulness of more or less sophisticated catalytic systems for the Knoevenagel reaction with malononitrile, a reaction that can take place under mild conditions without the need of a catalyst. From a sustainable viewpoint the questions are: Is it useful to increase the rate of a reaction that already occurs under mild conditions? Is it useful to spend resources and time in designing, characterizing and realizing complex catalytic systems for such reaction? Does it make sense to carry out the reaction under conditions such as to have a slower reaction rate and therefore to find a catalyst that is able to increase it
Modified nanocarbons as catalysts in organic processes
No full textThe application of nanocarbons as useful scaffolds for the production of a wide range of catalytic systems is an ever-growing field as witnessed by the huge amount of research on this topic. Both covalent and non-covalent modifications of nanocarbons represent the main routes to gain access to hybrid nanostructured catalysts. In this chapter the attention will be focused on nanocarbons, namely, fullerene, nanotubes, and graphene, employed for catalytic purposes covering both organocatalytic and metal-based (metal nanoparticles, organometallic complexes) reactions, whereas simple physical mixtures of nanocarbons and metal nanoparticles as well as examples dealing with electrocatalysis or photocatalysis are out of the scope of the present chapter. Because of the large number of publications in this field, we dealt some recent examples that represent a short overview on this topic that are not meant to be exhaustive but merely representatives of the subject
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
New concepts and applications in macromolecular chemistry of fullerenes
No full textA new classification on the different types of fullerene-containing polymers is presented according to their different properties and applications they exhibit in a variety of fields. Thus, because of their interest and novelty, water soluble and biodegradable C60-polymers are discussed firstly, followed by polyfullerene-based membranes where unprecedented supramolecular structures are presented. The following type of compounds are those involving hybrid materials formed from fullerenes and other components such as silica, DNA and Carbon Nanotubes (CNTs) where the most recent advances are shown. A most relevant topic is still that of C60-based Donor-Acceptor (D-A) polymers since their application in photovoltaics is nowadays among the most realistic applications of fullerenes in the so-called molecular electronics. The most relevant aspects in these covalently connected fullerene/polymer, as well as new concepts to improve energy conversion efficiencies are presented.
The last topics are related with those supramolecular aspects involving C60-polymer systems and self-assebling of C60-macromolecular structures which open a new scenario for organizing, by means of non-covalent interactions, new supramolecular structures at the nano- and micro-metric scale, in which the combination of the hydrofobicity of fullerenes with the versatility of the non-covalent chemistry afford new and spectacular superstructures
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