1,720,999 research outputs found
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
An analytic strategy for data processing of multimode networks
Full text linkComplex network data structures are considered to capture the richness of social phenomena and real-life data settings. Multipartite networks are an example in which various scenarios are represented by different types of relations, actors, or modes. Within this context, the present contribution aims at discussing an analytic strategy for simplifying multipartite networks in which different sets of nodes are linked. By considering the connection of multimode networks and hypergraphs as theoretical concepts, a three-step procedure is introduced to simplify, normalize, and filter network data structures. Thus, a model-based approach is introduced for derived bipartite weighted networks in order to extract statistically significant links. The usefulness of the strategy is demonstrated in handling two application fields, that is, intranational student mobility in higher education and research collaboration in European framework programs. Finally, both examples are explored using community detection algorithms to determine the presence of groups by mixing up different modes
Pure thick nickel coating obtained by electroless plating. Surface characterization and wetting properties
No full textPure nickel coatings were directly plated onto steel by using an electroless plating process. The effect of different synthesis strategies on the morphological surface was investigated and the study of growth mechanisms has provided useful information about the surface properties of coating. In this paper, several plating parameters (pH, temperature, solution composition and the ratio between the sample surface area and the volume of solution) were investigated by studying their influence on the plating rate. High thickness (30 μm) coatings were obtained after 2 h of plating at 85 °C. XRD, SEM and AFM analyses were performed to evaluate microstructure morphology and chemical composition of the deposited coatings. Surface analysis has shown the presence of a hierarchical structure with a macro-nano hierarchical structure and a nanostructured roughness; the influence of surface morphology on wetting properties was assessed. Electroless Ni plated samples exhibit wetting properties changing over time: as-coated samples show a super-hydrophilic behavior with a water contact angle 150°. This phenomenon was studied analytically by measuring the water contact angle at different exposure times and by investigating the causes of the surface properties modification. Results confirm that the variation in wettability can be attributed to the presence of airborne hydrocarbon adsorbates on the coating surface
Mechanical behaviour with temperatures of aluminum matrix composites with CNTs
Full text linkAluminum is a very useful structural metal employed in different industrial sectors, in particular it is used in
large quantities in automotive, aeronautic and nautical industries. The main reasons of its wide use are: a very
good oxidation resistance, excellent ductility, low melting temperature (660 °C) and low density (2.71 g/cm3).
However, in order to reduce the emissions and fuel consumption is necessary to reduce the overall weight of
vehicles by increasing mechanical properties of the structural material. The improvement of mechanical
properties is normally achieved through use of reinforcement in materials, used like matrix, in order to improve
some specific characteristics.
In this work composites of carbon nanotubes (CNTs) dispersed in aluminum were made. The most difficulties
in the preparation of this type of composite are represented by the low wettability between metallic matrix and
fillers and the possibility of the oxidation of metal during melting with consequent decreasing of mechanical
proprieties. The composite was obtained by three consecutive step: the first one is the functionalization of
fillers surface to improve the fillers dispersion, the second one is the dispersion of fillers in the matrix by
powder mixing and the third one is the melting and casting of the mix prepared.
In particular, fillers used are multi walled carbon nanotubes (MWCNTs) with functionalized surface by
treatment with a solfonitric solution. Melting and casting are carried out with the aid of an induction furnace
with a controlled atmosphere system and centrifugal casting. Argon is the inert gas used to prevent the
oxidation of aluminium during fusion. Young’s modulus was evaluated at different temperature and correlated
with the different CNTs percentage. The dispersion rate of fillers and the microstructure of the sample were
evaluated by FESEM micrograph
Abstract from XIV AIMAT National Congress - XI National Conference on Materials Science and Tecnology - July 12-15,2017 Ischia (NA) - "Ultralight magnesium alloy filled with micro and nano carbon structure"
No full textMagnesium is the lightest structural metal with a very low density
(1.74 g/cm3) and low melting temperature (650°C). In recent years, it has
been increasingly used in different industrial sector: automotive, aeronautic
and nautical industries. However, is interesting to improve its technological
properties. In this work, micro and nano fillers were added to magnesium
alloy with a centrifugal casting process directly in the metal. In particular,
carbon microfibers (CMFs) and carbon nanoplates (CNPs) were chosen as reinforcement.
In this work it was studied the influence of the dispersion of different
carbon fillers by measuring the mechanical properties of magnesium
micro and nano composites
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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