1,721,028 research outputs found
Coarsening of nanoporous Au during catalytic CO oxidation
No full textThis study focuses on the effects of catalytic activity on nanoporous Au catalysts fabricated by dealloying. Nanoporous Au structures are shown to coarsen with similar kinetics over a broad temperature range. A variation in the apparent activation energy suggests that coarsening is controlled by different rate-limiting steps at high and low temperatures
Morphology influence on elastic deformation behaviour of high porous ceramics. Experimental and phenomenological model predictions
No full textPorous ceramics based on clay powders have been fabricated resulting in an open-cells structure. High porosity, measured between 46 and 96%, has been correlated with effective Young's modulus obtained by mechanical tests. However, it is worth noting that pore fraction is not the only physical feature which has to be taken into account to understand the elastic behaviour. SEM inspections show morphologies composed by ligaments and mass agglomerations which can influence mechanical response of these structures. In this sense, a statistical estimation of characteristics lengths of structural elements has been performed in order to calculate Young's modulus by using a modified tetrakaidecahedral phenomenological model. Moreover, the proposed approach is capable of taking into account shear effect owing to ligaments thickness usually ignored by beam theory. A comparison between experimental and computed data is in good agreement
Thermal conductivity of porous building materials: An exploration of new challenges in fractal modeling solutions
Full text linkThe improvement in the insulation material performance is one of the recent crucial problems. The energy consumption in the construction and buildings field has a significant impact on the society and the environment. For these reasons, researchers have focused on studying their thermal behaviour in order to improve fabrication methods and material design structures. In this sense, a great contribution has been offered by the modeling procedures. A remarkable attention has been dedicated to the application of fractal geometry which seems to be a promising method to replicate the porous structures as well as to predict the effective thermal conductivity. In this paper, a review of different modeling procedures is presented, comparing both traditional and fractal theory‐based approaches. Fractal models demonstrate high reliability in reproducing experimental data under various conditions, including dry and moist systems. This is further enhanced by the application of recursive formulas, which streamline calculations even for complex porous microstructures. The choice between one model and another depends on the specific characteristics of the materials under study. In all cases, the versatility of the analytical procedures enables one to achieve a remarkable agreement with experimental data
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
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
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
- …
