1,720,986 research outputs found
Characterization of the gas–magmatic outflow at a volcanic vent through integral–equation based inverse acoustics
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Instituzione pratica dell' architettura civile per la decorazione de' pubblici, e privati edifici : preceduta da un articolo di Geometria in pratica ad uso delli disegnatori, et artefici
No full textdi Paolo Federico Bianch
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
Electromagnetic characterization of saline/acid ice mixture for shallow radar exploration
No full textThe aim of this work is the estimation of the electromagnetic parameters of the icy geomaterials present in Jovian satellite crusts. The first recognition of the Jupiter system, performed by the Voyager spacecraft, suggested the possibility of an ocean of liquid water beneath the ice shell of the two Jupiter's moons, Ganymede and Europa. In addition, the Galileo mission detected in the icy shell the presence of impurities like magnesium and sodium sulfates, and sulfuric and chloridric acids. JUICE - JUpiter ICy moons Explorer will investigate the potentially habitable zones in the Ganymede, Europa and Callisto moons. In particular a radar sounder (RIME) operating at 9 MHz, optimized for the penetration of the icy shell, will provide the subsurface survey up to a depth of about 9 km. The performance of RIME depends on the electromagnetic properties of the icy shells, which in turn are related to the impurity contents and temperature. In this scenario, we have performed measurements of dielectric properties of ice doped with MgSO4 , Na2SO4 , H2SO4 and HCl. The tests were performed as a function of frequency from 20 Hz to 30 MHz and temperature down to 100 K. In particular, the dielectric properties of the ice samples were measured using a capacitive cell and LCR meters. The values of real and imaginary parts of dielectric permittivity allow us to estimate velocity and attenuation of radar signals versus salts and acids content, to optimize the JUICE mission data analysis
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
Dielectric characterization of ice/MgSO4.11H2O mixtures as Jovian icy moon crust analogues
No full textOne of the main objectives of proposed missions to the icy Jovian moons is to prove the existence of the postulated subsurface ocean on Europa using radar sounders. The success of these missions will rely on the ability of the radar signals to penetrate ten kilometers of icy material that could potentially contain various types of impurities. In this work we quantify the impact of magnesium sulfate hydrates on the electrical properties of water ice by performing a series of dielectric measurements on different ice/MgSO4.11H2O mixtures as a function of frequency and at temperatures comparable with those expected on the icy satellite surfaces. Our results indicate that the salt only affects the real part of permittivity of the mixtures, whereas the imaginary part, hence the attenuation, does not significantly differ from that of pure ice. This means that in some regions signal penetration may be better than previously thought
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