1,720,955 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Cementation processes of Roman pozzolanic binders from Caesarea Maritima (Israel)
No full textA multi-analytical characterization study was performed on the pozzolanic binding composites used for the construction of Sebastos harbor in Caesarea Maritima, comparing underwater concretes to on-land mortars. Historically dated to the 1st Century BCE, the structure was erected by King Herod the Great as the largest ancient artificial harbor in the open sea. The combined interpretation of the results obtained through petrographic, mineralogical, spectroscopic, and microstructural/microchemical analyses indicated the use of different binder recipes, related to Roman and Phoenician-Punic technological practices, employing both natural volcanic pozzolans and artificial pozzolanic additives derived from the combustion of organics. Furthermore, the study unraveled the complex cementation processes of the binding composites, influenced by diversified chemical-physical-biological conditions of the precipitating environment such as water salinity and bacterial activity, leading to the formation of unconventional carbonates, as well as peculiar hydrated calcium aluminosilicate (C–A–S–H) and magnesium aluminosilicate (M–A–S–H) phases. The results constitute a relevant contribution to the understanding of the reactive pathways of ancient and modern pozzolanic systems
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Prescreening Hydraulic Lime-Binders for Disordered Calcite in Caesarea Maritima: Characterizing the Chemical Environment Using FTIR
No full textHydraulic lime binders are considered a technological marvel which revolutionized construction techniques in antiquity. The core material is made of a binder that is a mixture of calcite and hydraulic phases, which are amorphous silicate compounds that nanostructurally polymerize into insoluble phases that harden even underwater, formed during the reaction between lime and reactive silicates such as volcanic ash. This is also what makes hydraulic lime so hard to radiocarbon (14C) date. These insoluble phases contain carbonates that may set centuries following their application, resulting in younger ages, which may contaminate the calcite fraction that is favorable for 14C dating. This calcite fraction forms upon the incorporation of atmospheric carbon dioxide during the setting of the hydrated lime. Therefore, different characterization methods are being constantly developed for identifying and characterizing the components of hydraulic lime-binders. In this work, we present a rapid characterization technique based on Fourier transform infrared spectroscopy (FTIR) that characterizes the atomic disorder and chemical environment of the carbonates and silicates fractions in the binder. The atomic disorder of the calcite crystallites was determined by the ν2 and ν4 vibrational modes, and the silicates were characterized by the main peak asymmetry and full width at half maximum (FWHM). Different hydraulic binders from Caesarea Maritima were examined, including Herodian mortars from the underwater breakwater and on-land plasters and mortars from the ports warehouse and vaults. Hydraulic binders, in which the calcite fraction in the binder shows atomic disorder that is comparable to modern plaster binders, was associated with silicates that have asymmetry and FWHM of clays and quartz. These materials are considered to be in good preservation state for 14C dating since their carbonates crystallites are disordered and did not interact with the environment chemically to form stable and ordered crystals. Interestingly, the atomic disorder of binders that underwent chemical alterations and recrystallization processes, are associated with reactive silicates aggregates such as volcanic ash (pozzolana). These results suggest a new way to prescreen materials for radiocarbon dating based on the composition of lime-binders and preservation state of the carbonate fraction and hydraulic products
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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