1,720,963 research outputs found
"Vis grata puellis". Fortuna di un pregiudizio: il "caso" Lucrezia
No full textIl contributo si propone di rintracciare, attraverso un breve excursus nella cultura umanistica, la permanenza in società contrassegnate da profondi mutamenti culturali, di modelli e stereotipi sulla violenza sessuale che affondano le loro radici lontanissime nella cultura classica e che si fondano sull’atavica diffidenza nei confronti della presunta vittima della violenza e sul presupposto del quasi inevitabile consenso/assenso della donna
La radicalità e la persistenza di questo modello culturale trova conferma nella sua applicazione a Lucrezia, la matrona romana celebrata dalla tradizione come exemplum pudicitiae . In un manoscritto miscellaneo di età umanistica in cui vengono tramandati tre excerpta di carattere retorico, la virtuosa sposa di Collatino si ritrova ad essere protagonista in un vero e proprio processo orientato a stabilirne ruoli e responsabilità nello stuprum perpetrato da Sesto Tarquinio.This paper is a reflection on a deeply rooted and lasting cultural model: the distrust of an alleged victim of sexual violence. The proof of its reception can be found out in the rediscovery of Lucrezia’s “case” during Humanism: the suspicion of guilt also affects the idea of Roman matron, traditionally celebrated as an exemplum pudicitiae
Solid-state C-13 nuclear magnetic resonance spectra of four crystalline forms of isotactic poly(4-methyl-1-pentene)
No full textFour crystalline forms of isotactic poly(4-methyl-1-pentene) (i-P4MP) (forms I, II, II, and IV) have been studied through solid-state C-13 NMR CP-MAS spectroscopy. The assignment of the resonances observed in the C-13 NMR CP-MAS spectra was made by dipolar dephasing experiments. The presence in all spectra of two distinct resonances, separated by approximate to 3 ppm, of the methyl carbons indicates that the two methyls belonging to the monomeric unit are nonequivalent. This has been explained on the basis of the gamma-gauche shielding interaction and of the conformations of polymer chains and lateral groups. The resonances observed in the spectrum of form III are markedly deshielded compared to those of other forms, whereas the resonances of form I are deshielded compared to those of form IV. This deshielding has been consistently interpreted on the hypothesis that the amount of the gamma-gauche shielding effect depends on the value of the torsion angles of the main chain. Indeed, the torsion angles of the main chain for the 7/2 helical conformation of form I deviate, on average, by 12-15 degrees from the exact staggered values of 60 degrees and 180 degrees (the average values of the torsion angles are theta(1) = 72 degrees and theta(2) = 195 degrees) they deviate by 22-26 degrees for the 4/1 helical conformation of form III (theta(1) = 82 degrees and theta(2) = 206 degrees). The gamma-gauche shielding parameter, normally -5 ppm when the gauche angle is nearly 60 degrees, decreases to a value between -2 and -2.5 ppm when the torsion angle deviates by nearly 20 degrees from 60 degrees. In the form IV, the upfield shift of the resonances, compared to forms I and III indicates that the carbon atoms experience a full gamma-gauche shielding interaction and, hence, the main chain torsion angles theta(1) and theta(2) are near 60 and 180 degrees, respectively, typical of a helical 3/1 conformation. This analysis allows us to suggest that the form IV of i-P4MP is characterized by chains in 3/1 helical conformation. The resonances of the methyl carbons of the four forms of i-P4MP show narrow splittings (1-2 ppm) which should be traced back to packing effects. This has provided a chance of testing the packing model of form I and form III proposed in the literature. In the spectrum of form I, the resonance of backbone methine carbons is also split in a doublet. This splitting is due to conformational effects, rather than packing effects and confirms that, according to the refinement of the crystal structure of form I, the chains assume a helical conformation slightly distorted from the uniform 7/2 helix. The succession of torsion angles along the main chain is ...TGT'G " T " G "..., instead of (TG)(n). Therefore, backbone methine carbons of different monomeric units are conformationally nonequivalent because they experience different amounts of gamma-gauche shielding effects owing to different values of the gauche torsion angle theta(1) of different monomeric units
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
Properties of poly(urea-formaldheyde) microcapsules containing an epoxy resin
No full textPhysical properties of urea-formaldehyde microcapsules containing an epoxy resin are presented and discussed. Microcapsules were prepared by in situ polymerization of monomers in an oil-in-water emulsion. Differential scanning calorimetry, thermogravimetric analysis, and scanning electronic microscopy were applied to investigate thermal and morphological microcapsule properties. Microencapsulation was detected by means of FTIR and Raman techniques. It was found that the amount of encapsulated epoxy resin as well as the extent of urea-formaldehyde polymerization depends on the reaction temperature and the stirring speed
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
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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