1,720,986 research outputs found

    Low-velocity impact behaviour of fibreglass-aluminium laminates

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    Low-velocity impact tests were performed on fibreglass–aluminium composites made of 2024 T3 sheets and S2-glass/epoxy prepreg layers, using an instrumented falling weight machine. For comparison purposes, similar tests were carried out on monolithic 2024 T3 sheets of equivalent thickness. In the tests, the impact speed, mass, and energy were varied, to ascertain the influence of these parameters on the material response. From the results obtained, the overall force–displacement curve only depends on the impact energy, rather than on the mass and speed separately. Further, the energy required for penetration is higher for monolithic aluminium than for the fibreglass– aluminium. However, the latter material seems to offer better performance than carbon fibre- and glass fibre-reinforced laminates in terms of penetration energy, damage resistance, and inspectability. The main failure modes of fibreglass – aluminium were assessed by both ultrasonic C-scan and chemical grinding of aluminium sheets. It was found that the energy required for first failure is very low, whereas the energy level resulting in first fibre failure is similar to that inducing first cracking in the 2024 T3 sheets. From the experimental data, simple empirical relationships were found for the calculation of maximum contact force, energy, and residual displacement as a function of the maximum displacement

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

    Drawing the Materials Balance for an MBT cycle from Routine Process Measures in a Plant located in Venice

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    An observation term was carried on in an MBT plant owned and run by a public Company to treat MSW left by separate collection. All observations and measurements were made without interfering with the ordinary operation rules, in order to assess the efficiency of one process cycle for a given batch of waste. Analytical data came from both a) process instruments and b) physical analysis of a batch of waste entering / exiting from a selected bio-cell. From the process mass losses (about 37% – including moisture evaporation – in that single process cycle) the theoretical amounts of water and carbon dioxide produced by biodegradation were calculated. A verification of the results was tried through a thermal balance, comparing the energy released by degradation with the energy losses from the bio-cell. The results showed a fair agreement, within 80%; what appeared critical is the knowledge of the chemical composition of fermentable waste (taken as cellulose as first attempt) and the actual amount of heat developed by biological oxidation

    The immunomodulatory effect of probiotics beyond atopy: an update

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    Background: In the past decades, the theory of "allergen avoidance" was considered the standard treatment for preventing the onset of allergic diseases. Recently, the concept of "immune tolerance" has replaced this old theory, and induction of tolerance by exposure is actually considered the appropriate method for preventing atopic diseases and other immunomediated pathologies. On the other hand, it is obvious that for public health reasons, abandoning current medical and hygienic practices is not desirable; therefore, safe alternatives, such as probiotics, have been suggested for providing necessary microbial stimulation. Objective: The purpose of our review is to describe the immunomodulatory and anti-inflammatory properties of probiotics, reporting literature data on their effect when used for the treatment of immunomediated diseases. Materials and methods: Articles reporting the evidence on the use of probiotics in immunomediated diseases, such as atopy, cow's milk allergy and rheumatoid arthritis (RA), and in inflammatory diseases, such as inflammatory bowel diseases (IBDs), with or without statistical meta-analysis, were selected in three different search engines: (1) MEDLINE via PubMed interface, (2) Scopus and (3) Google Scholar for all articles published from inception to July 2013. Titles and abstracts of identified papers were screened by two independent reviewers to determine whether they met the eligibility criteria of interest to develop our review. Subsequently, full texts of the remaining articles were independently retrieved for eligibility by the two reviewers. Results and discussion: The recent literature is focusing its interest towards the immunologic properties of relatively harmless organisms, including lactobacilli and bifidobacteria, helminths and saprophytic mycobacteria that may skew immune responses towards immunoregulation by inducing Treg cells, rather than eliciting a pro-inflammatory immune response. For this reason, recent researches have been addressed on the use of probiotics to promote immunoregulation in atopic diseases, such as atopic/eczema dermatitis syndrome and food allergy, as well as in inflammatory-based diseases such as IBDs, RA and bronchial asthma
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