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Primi secoli. Collana diretta da F. Cocchini e F. Ruggiero.
No full textLa collana pubblica studi e testi del cristianesimo antico, medievale e moderno. Dal 2006 al 2011 sono stati pubblicati volumi: F. Cocchini, Origene teologo esegeta per una identità cristiana, Bologna EDB, 2006; Gregorio Magno. Vita di san Benedetto, Commentata da Adalbert de Vogué, Bologna EDB, 2009; M. Simonetti-E.Prinzivalli, Storia della letteratura cristiana antica, Bologna EDB 201
Constrained Inversion of Rheological Data to Molecular Weight Distribution for polymer melts
No full text
Poliarilati e poliacetali: determinazione della distribuzione dei pesi molecolari da proprietà reologiche
No full textMolecular weight distribution from linear viscoelastic properties in linear flexible polymers
No full textA generalized relation between MWD and relaxation time spectrum
No full textAbstract An inversion procedure for converting linear
viscoelastic properties of polymer melts into molecular
weight distribution (MWD) described by the generalized
exponential function (GEX) has been implemented and
applied in a previous work (Cocchini F, Nobile MR. Rheol
Acta 42:232–242, 2003). It is based on the elegant relationship
between the relaxation spectrum and the MWD function
proposed by Thimm W, Friedrich C, Marth M. J Rheol
43:1663–1672 (1999). In the present paper, such a methodology
has been generalized to properly account for sharp
MWDs, in particular, nearly monodisperse or blends of nearly
monodisperse polymer samples. The generalized relationship
has been verified and calibrated using the BSW kernel
(Baumgaertel M, Schausberger A, Winter HH. Rheol Acta
29:400–408, 1990) to describe the rheological behavior of
some Polystyrene samples from the literature, in terms of the
known MWD. Then, it has been successfully applied to the
inversion problem for a wider set of samples, with both broad
and sharp distributions. The Rouse contribution at high
frequencies and the accelerating effect on the relaxation times
due to polydispersion have been also addressed.
Keywords MWD. Polydispersity . Relaxation time spectrum . Linear viscolelasticit
Approfondimenti su una metodologia per ottenere la distribuzione dei pesi molecolari dalla risposta viscoelastica lineare di polimeri lineari
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