1,720,957 research outputs found
Fattori di rischio dell’abuso di alcolici in adolescenza e il loro effetto sommativo
No full textLa letteratura ha identificato alcuni fattori associati all’abuso di alcolici durante la fase adolescenziale che possono essere raggruppati nelle seguenti categorie: 1) le relazioni genitori-figli, 2) la frequentazione di pari devianti, 3) il funzionamento psicologico (condotta antisociale) e 4) gli eventi di vita negativi. Lo scopo di questo studio è quello di verificare l’importanza complessiva di questi fattori rispetto all’abuso di alcolici su un campione di adolescenti italiani. E’ stato somministrato, a scuola, un questionario a 405 adolescenti (152 maschi, pari al 37.4%; 253 femmine, pari al 62.6%) di età compresa tra i 16 e 20 anni (M = 18.2, D.S. = .69). I risultati hanno confermato come l’abuso di alcolici in adolescenza sia la conseguenza di un’accumulazione di fattori di rischio tra loro legati. In particolare, viene confermato il ruolo determinante e preponderante della frequentazione di pari devianti (OR = 2.48). Sono inoltre discusse le possibili implicazioni pratiche rispetto all’utilizzo dei risultati
A methodology for mould conformal cooling channels optimization exploiting 3D printing
Full text linkWith the advent of 3D printing, it is now possible to produce any part or system with an approach than makes design much deeply interlaced with production. In this scenario, CAE has gained power thanks to the possibility of thinking and then manufacture ideas that go well beyond what was possible in the past. This design approach is perfectly suitable to push forward mould conformal cooling performance. In this work, a coupling of CAD, CFD and 3D printing supported by experimental tests was applied to define a design procedure for conformal cooling channels. In particular, cooling channels for a mould were engineered via CAD, then tested via CFD and, after an initial optimization procedure, the chosen design was 3D printed in specimens suitable to be mounted on a heat exchanger (HX) experimental test rig that was especially adapted for the scope. Fluids temperature, volume flow rates and heat transfer performance were measured. A feedback loop was considered to link measurements and channels redesign. Results together with design and testing procedures are reported and commented
Thermo-fluid dynamics modelling of conformal cooling channels produced with material jetting technology
No full textMaterial Jetting is an additive manufacturing technology that uses photopolymerisation reaction to produce parts with high accuracy and low roughness. Moreover, because the support material is easily removed by thermal treatment, it results as an additive process able to guarantee very high level of shape complexity. Nowadays, thanks to new commercial polymers able to withstand higher temperatures, this technology starts to find applications in the production of insert mould for injection moulding process. The authors present a study about the thermo-fluid dynamics behaviour of samples of inserts mould having conformal cooling channels. The mould heat transfer performances were tested via experimental and numerical techniques. Results suggest that for the prediction of the transient thermal behaviour of these new polymers, it is quite important the accurate evaluation of material thermal properties. For the design based on numerical approaches, challenges could arise from the wide range of variations found on thermal properties
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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