1,721,045 research outputs found
Computer Simulations Techniques for Modelling Biomaterials
No full textComputational simulation of biomaterials constitutes a fundamental and fascinating research area, constantly growing thanks tothe increasing availability of computational resources. The combined approach of classical and ab-initio methods has allowedthe modelling of bioceramics (both bioactive glasses as the 45S5 Bioglass® and hydroxyapatite) and their complex interactionswith the biological environment
Vibrational features of phosphor-silicate glasses: Periodic B3LYP Simulations.
No full textB3LYP periodic calculations with double-f polarised basis set using CRYSTAL06 code have been run on a bioactivephospho-silicate glass similar in composition to Bioglass 45S5 (46.1 SiO2, 24.4 Na2O, 26.9 CaO and2.6 P2O5 mol%) and a phosphorous-free soda-lime glass (49.5 SiO2, 24.2 Na2O and 26.4 CaO mol%). Initialstructures have been obtained through a melt-quench process by classical molecular dynamics techniquesand the effect of phosphorous on the glass network structure and dynamics have been assessedby B3LYP vibrational spectra
Le imposte sul reddito
No full textIl lavoro si propone l’obiettivo di analizzare il trattamento contabile delle imposte sul reddito, secondo i principi contabili internazionali, muovendo, secondo la struttura dello standard vigente in materia, da un breve inquadramento generale per poi procedere all’investigazione delle regole che governano, in particolare, la ricognizione delle imposte differite nei prospetti di sintesi contabile
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
B3LYP Simulation of the Full Vibrational Spectrum of 45S5 Bioactive Silicate Glass compared to v-Silica
No full textThe IR spectrum of the Bioglass 45S5 (of composition 46.1 SiO2, 24.4 Na2O, 26.9 CaO, and 2.6 P2O5mol %) has been simulated by means of periodic ab initio B3LYP calculations. The initial glass structureunit cell envisaging 78 atoms was generated through a melt quench process by means of classical moleculardynamics simulations. The molecular mechanics optimized unit cell has then been fully reoptimized(both unit-cell parameters and internal coordinates) at B3LYP level in a periodic approach using Gaussianbasis sets of double- quality by means of the CRYSTAL06 code. Although long-range structural propertiescannot be modeled by using this ab initio approach because of the intrinsic amorphous nature of theglass, the quantum mechanical simulation proved to be extremely effective in predicting and analyzingthe vibrational features of this biomaterial. The effect of modifiers Na and Ca cations on the networkdynamics has been assessed by comparing the 45S5 vibrational spectrum with that of amorphous V-SiO2,both simulated at the B3LYP level. A detailed assignment of each spectral peak to the correspondingvibrational mode of the two glasses has been addressed and the role of cation modifiers on the vibrationalfeatures has been analyzed in greater details. This may be useful to support further IR and Ramaninvestigations of the bulk structure of these materials
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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