1,721,026 research outputs found
Bio-materiali per il corpo umano. Museo Interattivo del corpo umano Corporea
No full textCura e Responsabilità scientifica, con Mario Malinconico dell'esposizione “Bio-materiali per il corpo umano” nell'ambito del museo interattivo del corpo umano Corporea inaugurato il 4 marzo 2017
Thermal oxidative stability and effect of water on gas transport and mechanical properties in PA6-EVOH films
No full textBlending polyhydroxybutyrate with tannic acid: a way to enlarge the processability window
No full textEffect of natural antioxidants on the stability of polypropylene films
No full textA preliminary study on the efficiency of agri-food industry wastes as stabilizers for polypropylene (PP) films is reported. Several analytical techniques were employed to evaluate the stabilization effectiveness of the additives. DSC and CL analysis performed on unaged samples confirmed the antioxidant activity of natural additives, and provided the following order of efficiency: red grape seeds > white grape seeds > tomato extracts. The films were also artificially aged at 70 °C, and FTIR spectroscopy confirmed the stabilization trend obtained from the unaged films. Kinetic analysis of TG data alongside tensile tests indicated that the tomato extract is a good thermal and processing stabilizer, but it is sensitive to oxidation. In contrast, grape seeds provide long-term stabilization to PP under conditions of oxidative degradation. Our results show that tomato and wine processing by-products have good potential to be exploited as a low-cost source of value-added phytochemicals
Blending poly(3-hydroxybutyrate) with tannic acid: Influence of a polyphenolic natural additive on the rheological and thermal behavior
No full textPoly(3-hydroxybutyrate) (PHB) is a biodegradable polymer, whose applicability is limited by its relatively poor mechanical properties and narrow processing window. In this paper, a natural polyphenolic additive, tannic acid (TA) was used as thermal and processing stabilizer for PHB. The thermal stability of both neat and TA-doped PHB samples was studied by rheology and calorimetry. The experimental results show that the neat PHB massively degrades and that the addition of tannic acid enhances the thermal stability of PHB, thus widening the processing window of the polymer. Physical and chemical interactions between the polymer and the additive were considered as key factors to interpret the
experimental data. The described results are of interest for the development of sustainable alternatives to synthetic polymer additives, by increasing the applicability of bio-based materials
Preparation and characterization of polybutylene succinate (PBS) and polybutylene adipate-terephthalate (PBAT) biodegradable blends
No full textBiodegradable polymer films based on polybutylene succinate (PBS) and polybutylene adipate terephthalate
(PBAT) blends with varying weight ratios were prepared by extrusion and chill roll calendering. The films were
characterized by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), mechanical tensile tests,
scanning electron microscopy (SEM), and rheology. In the blends with higher content of PBAT, PBS crystallization was
inhibited. As for mechanical performance, increasing the PBS content in PBAT an increase in the stiffness and a decrease
in the ductility of the blends is detected. Finally, rheological measurements evidence an increase in the viscosity of the
blends with increasing the PBAT conten
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
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
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