1,721,000 research outputs found
Affrontare la tempesta, Navigazione antica e manovre in condizioni meteo-marine estreme
No full textIn una lettura comparativa col dato etnografico e con la tradizione nautica precedente alla motorizzazione, le fonti storiche consentono di riconoscere e analizzare le tecniche usate dai naviganti antichi per affrontare la navigazione con condizioni meteo-marine estreme, dunque anche con tempo tempestoso. Le soluzioni pratiche adottate nell'antichità furono impiegate anche nell'età medievale e moderna, per giungere in diversi casi fino ai nostri giorni, nell'ambito di un contesto nautico che nei suo tratti fondamentali è rimasto sostanzialmente simile, per lo meno fino al tramonto della vela. Particolarmente interessante nel contesto di indagine risulta il resoconto del viaggio di Paolo di Tarso da Cesarea di Palestina a Roma, nel corso del quale avvenne il celebre naufragio a Malta. Il racconto, contenuti negli Atti degli Apostoli 27, descrive una serie di procedure che i marinai misero in atto per fronteggiare una terribile tempesta, che portò la nave alla deriva per quattordici giorni.In a comparative reading with the ethnographic data and the nautical tradition before the development of the engine, the historical sources make it possible to recognise and analyse the techniques used by ancient mariners to cope with navigation in extreme heavy weather and sea conditions, including stormy weather. The practical solutions adopted in antiquity were also employed in the medieval and modern ages, and in several cases up to the present day, within a nautical context that has remained substantially similar in its fundamental features, at least until the demise of sailing. Particularly interesting in the context of the investigation is the account of Paul of Tarsus' voyage from Caesarea of Palestine to Rome, during which the famous shipwreck in Malta occurred. The account, contained in "Acts of the Apostles" 27, describes a series of procedures that the sailors put in place to cope with a terrible storm, which set the ship adrift for fourteen days
Enhancing the luminescence efficiency of silicon-nanocrystals by interaction with H+ions
No full textThe emission of silicon nanocrystals (Si-NCs), synthesized by pulsed laser ablation in water, was investigated on varying the pH of the solution. These samples emit μs decaying orange photoluminescence (PL) associated with radiative recombination of quantum-confined excitons. Time-resolved spectra reveal that both the PL intensity and the lifetime increase by a factor of ∼20 when the pH decreases from 10 to 1 thus indicating that the emission quantum efficiency increases by inhibiting nonradiative decay rates. Infrared (IR) absorption and electron paramagnetic resonance (EPR) experiments allow addressing the origin of defects on which the excitons nonradiatively recombine. The linear correlation between the PL and the growth of SiH groups demonstrates that H+ions passivate the nonradiative defects that are located in the interlayer between the Si-NC core and the amorphous SiO2 shell
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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