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Il S.I.N. “Brescia-Caffaro” come espressione degli equilibri tra valori: Lavoro, Salute e Rete in evoluzione nel tempo e nello spazio
No full textEffect of an organoclay on the photochemical transformations of a PBAT/PLA blend and morpho-chemical features of crosslinked networks
Full text linkIn this work, we report the effect of an organoclay on the photochemical weathering of nanocomposites based on a poly(butylene adipate-co-terephthalate) (PBAT)/poly(lactic acid) (PLA) blend. The evolution of physicochemical properties was monitored by integrating spectroscopic, mechanical, and morphological analyses. A robust relationship was found between the molecular transformations of the polymer macromolecules and the morpho-mechanical properties of irradiated films. Moreover, the analysis of insoluble fractions extracted from nanocomposites pointed out that free-standing, porous structures, displaying an unprecedented thickness as great as 100 μm, were formed, thus unambiguously demonstrating that the organoclay increased the propagation depth of photochemical crosslinking reactions by 10 times with respect to previously reported results on PBAT. The pore architecture and chemical structure of such crosslinked networks proved to change depending on organoclay content of films
Hybrid biocomposites based on polylactic acid and natural fillers from Chamaerops humilis dwarf palm and Posidonia oceanica leaves
Full text linkPlatelet-like and fibrous lignocellulosic fillers were achieved from the leaves of Chamaerops humilis (CHL) and Posidonia oceanica (POL) and used as a hybrid reinforcement for a polylactic acid (PLA) matrix at three different loading levels (from 5 to 20%). The materials were fully characterized from a morphological, physicochemical, mechanical, and dynamic-thermomechanical point of view. When compared to their counterpart containing either CHL or POL only, the resulting hybrid biocomposites showed the highest mechanical properties, with strengthening and stiffening effects respectively up to 120% and 50% higher than those expected from the linear combination of the two, and higher dynamic-mechanical performance, with storage moduli in the rubbery region 10 times higher than those of composites containing solely CHL or POL. Such synergistic efficiency is likely due to the formation of a strong and extensive interphase region, promoted by the balanced effect of morphological features of the hybrid network and physicochemical characteristics of the components. These green materials could find applications as panels for furniture or in the automotive industry
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
Photochemical degradation of PLA-based green composites containing waste biomass from Posidonia oceanica, Chamaerops humilis and Ailanthus altissima: A comparative study
Full text linkThe photochemical degradability of PLA-based composites containing three different natural fillers, namely Posidonia oceanica (PO), Chamaerops humilis (CH), and Ailanthus altissima (AA), was evaluated to understand how the morphological and physicochemical features of these composite systems affect their durability. Composites containing 10% or 20% of filler were prepared by melt-processing and subjected to accelerated weathering involving UV irradiation and condensation cycles. The materials were thoroughly characterized, and the evolution of morphological, physicochemical, and mechanical properties was monitored upon aging time. The results demonstrate the significant impact of filler type on the photochemical stability of PLA-based composites. PO and CH fillers, with high porosity, resulted in less compact composites that underwent rapid hydrolytic degradation, experiencing surface and bulk erosion. AA composites exhibited the highest durability, with their dense morphology effectively delaying degradation. Overall, composites with 10% PO and 20% CH had the lowest stability (less than 6 h), the other PO- and CH-series materials retained durability for 24-30 h, similar to neat PLA, while AA-series composites proved to retain their mechanical properties for up to 36 h
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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