1,721,010 research outputs found
Sperimentazione di ricerca per una formazione situata in un Master di didattica delle scienze: il caso del tempo
No full textThe efficient identification of horizontal meandering in raw ultrasonic anemometer data
No full textThis paper shows a new experimental method for the detection and identification of sub-mesoscale low-frequency components, in particular horizontal meandering, in raw data from three-axial ultrasonic anemometers and other high resolution, high sampling-rate three-dimensional wind sensors. The proposed method is a combination of autocorrelation-based detection and FFT-based filtering, well known in literature. The results of the application of the described method to a sample of hourly raw data files are shown as well. The method can be used as a building block for eddy covariance and other data processing procedures as well as in all the situations where very short time scales (about 10s) are relevant, such as in odour or toxic chemical dispersion
The Positive Ion Injector for ALPI
No full textIn the framework of the ALPI upgrading, a new positive ion injector is foreseen in order to be able to accelerate ions with masses of the order of 200 and with high charge states from the velocity of β = 0.009 up to β = 0.055. The structures chosen for that velocity range are superconducting radio frequency quadrupoles operating at a frequency of 80 MHz, which is the operating frequency of the ALPI low β cavities. The paper describes the current status of the project including beam dynamics, cavity design, beam transfer lines and vacuum, control and cryogenic systems
Characterization of vacuum brazed joints for superconducting cavities
No full textBrazing is a process to join metallic and non-metallic materials, without any melting or plastic state of the base metals. The poor wettability of ceramic may be improved by the use of alloys containing an element capable of changing the chemistry of the ceramic surface (active braze). In this paper we propose the substitution of the Electron Beam welding with Vacuum Brazing in order to join the resonator components, Nb, Cu OFHC, and Al2O3, with stainless steel flanges, in superconducting resonant cavities. Several combinations of brazed joints have been tested. The characterization of the joints has been performed with SEM-EDS and MICROPIXE. All the joints fulfil the requirements
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
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