1,720,995 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
Crystal and molecular structure of (-)-1,2-O-isopropylidene-3-O-methyl-7,8-dideoxy-beta-L-glycero-D-gluco-non-7-enofuranurono-9,6-lactone, C13H18O7.
No full textTrifluoromethyl-substituted Bis(Pyrazolyl)Methanes as Ligands for Copper and Silver: Synthesis and Spectroscopic and Structural Characterization
No full textNew fluorinated bis(pyrazolyl)methanes with the general formula RCH(PzF)2 [R ) H,
PzF ) 3-(trifluoromethyl)pyrazolyl, 3,5-bis(trifluoromethyl)pyrazolyl; R ) Ph, PzF ) 3,5-bis(trifluoromethyl)
pyrazolyl] have been prepared, and their reactivity with copper and silver salts has been
studied. Copper derivatives Cu[RCH(PzF)2](L)(OTf) [R ) H, PzF ) 3-(trifluoromethyl)pyrazolyl,
3,5-bis(trifluoromethyl)pyrazolyl; R ) Ph, PzF ) 3,5-bis(trifluoromethyl)pyrazolyl, L ) CO, cyclooctene
(coe); R ) Ph, PzF ) 3,5-bis(trifluoromethyl)pyrazolyl, L ) coe, 4-vinylanisole (van), and triethylvinylsilane
(tevs)] have been isolated by reacting Cu(OTf)(toluene)0.5 with the bis(pyrazolyl)methane
ligand in the presence of olefin or CO. Some of them have been structurally characterized (R ) H, PzF
) 3-(trifluoromethyl)pyrazolyl, 3,5-bis(trifluoromethyl)pyrazolyl, L ) CO). These compounds
are monomeric and show strong interactions between copper and one oxygen atom of the triflate
moiety. [Bis[3,5-bis(trifluoromethyl)pyrazolyl]methyl]silver complexes have been prepared from
AgBF4 and the ligand. The coe derivative [Ag{CH2(3,5-(CF3)2Pz)2}(coe)]BF4 has been obtained in good
yields
Trifluoromethyl-Substituted Bis(pyrazolyl)methanes as Ligands for Copper and Silver: Synthesis and Spectroscopic and Structural Characterization
No full textEvaluation of corrosion conditions of reinforced concrete structures exposed to chloride-bearing environment
No full textTo plan the maintenance of reinforced concrete structures, damaged by chloride-induced corro-sion, their corrosion conditions need to be properly assessed and this can be carried out only if there is a deep knowledge of the degradation mechanism. This paper deals with the mechanism of chloride-induced corrosion of steel in concrete, analysing the factors affecting the time to corro-sion initiation and corrosion propagation. Attention will be then focused on studies carried out in recent years at the mCD Concrete Durability lab of Politecnico di Milano, which were aimed at investigating the corrosion rate of carbon steel rebar embedded in concrete exposed to chloride penetration
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
Structural modelling of the response of deteriorated rc and psc members: Levels of approximation for model code 2020
No full textThe assessment of reinforced concrete structures affected by deterioration such as reinforcement corrosion involves the use of different models, according to different scientific and technical purposes. The paper presents a framework for structural modelling approaches previously developed by the authors to fit in the concept of Levels of Approximation for Model Code 2020. The concept is here extended to include different accuracy levels in deterioration modelling. The paper moves from simple strut and tie models to analytical models and finite element numerical studies. The possibility of an extension of the framework to modelling the freeze-thaw deterioration is highlighted. The conclusions highlight the available techniques and the needs for research developments
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