1,721,407 research outputs found
La responsabilità dell'ente. I criteri di imputazione. Il gruppo di imprese, in Manuale della responsabilità degli enti
No full textCenni sull'amministrazione e il controllo giudiziari nella normativa antimafia, in Manuale della responsabilità degli enti
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I reati-presupposto della responsabilità dell'ente, in Manuale della responsabilità degli enti
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Le deroghe alla disciplina processuale per banche, intermediari finanziari e assicurazioni, in Manuale della responsabilità degli enti
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Application of synchrotron radiation micro-CT to local morphological and numerical characterization of short fibre reinforced polymer composites
No full textThe behavior of materials with a complex structure strongly depends on the
spatial arrangement of their components. In mechanical parts of short glass
fibre reinforced polymer (SFRP) obtained by injection moulding, processing
conditions produce complex orientation patterns that in°uence the mechanical
properties of the component. For example, different fatigue (i.e. failure caused
by cyclically repeated loads) behaviors can be observed when short fibre rein-
forced polyamide notched specimens of same geometry are injection moulded
through gates whose position is varied. This effect appears to be due to
the different fibre orientation patterns obtained and it can be interpreted
in terms of different local material properties related to fibre orientation and
distribution. Traditional, destructive, approaches to fibre pattern identification
are affected by severe limitations. Recently, a novel technique based on micro-
tomography 3D reconstruction of the fibre structure has been introduced for
quantification of fibre pattern
Microwave-assisted Palladium-catalyzed cyclization of allenyl indoles
No full textAs a part of our study directed to the development of intramolecular palladium-catalyzed procedure in obtaining polyheterocyclic systems, and to study the reactivity of indole derivatives, the present work is regarding the reactivity of N-allenyl 2-indolecarboxamides. Heteroannulation processes involving an allenyl functional group have been extensively studied in the past years, in particular allenamides represent a versatile and effective class of building blocks for generating nitrogen-containing heterocycles. The interest of our substrates is due to the presence of the allenyl group tethered to the indole nucleus which nitrogen atom should be suitable nucleophile to give intramolecular cyclization. The pathway proceeds with the involvement of a -allylpalladium intermediate, generated by carbopalladation of the allene moiety. The complex plays a fundamental role in terms of regio- and stereoselectivity. The subsequent step occurs following divergent outcome but in both cases the carbon in the position of the 1,2-diene is involved. The reaction is totally regioselective giving only the exo-cyclized product.
The key step, in the presence of an aryl iodide, consists of a carboamination process, to give imidazo[1,5-a]indole derivatives. The second strategy, without the intervention of the aryl iodide, consists of a new hydroamination reaction that proceeds exclusively under microwave irradiation.
The alternative hypothetical product arising from the involvement of indole C-3 nucleophile to the -allyl complex is never observed
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