1,720,990 research outputs found
Determining the strength of 3D printed concrete with the modified slant shear test
Full text linkThis study deals with the assessment of the load-bearing capacity of layered 3D printed concrete (3DPC) using a modified slant shear test (MSST) to define a Mohr's envelope. To this aim, the established modified Coulomb yield condition of the concrete is complemented by a Coulomb failure criterion of the layer joints (cold or dry joints). Due to the anisotropy inherent to 3DPC elements, caused by the interlayer of printed concrete, the test setups commonly used for conventional concrete are inadequate to assess the load-bearing capacity of 3DPC. A total of 45 3DPC specimens with different inclinations of the concrete printed layers, including a cold joint with 30 min time gap were tested using the MSST. The results showed a high strength of the interfaces with two different failure modes, depending on the inclination of the layers: (i) concrete matrix failure and (ii) layer interface failure, where the latter governed for layer inclina- tions of 60 and 75 with respect to the horizontal plane. The test campaign con- firms that the proposed MSST is a highly practical test method that enables determining the parameters governing a Mohr's envelope of layered 3DPC and can thus be used to reliably characterize its load-bearing capacity
Analytical and numerical modelling of existing RC frames with smooth rebars
No full textThe work refers to the seismic behaviour of existing reinforced concrete (RC) frame buildings reinforced with plain rebar. A focus on the modelling of their flexural response is proposed, to explicitly consider the effect of smooth reinforcement slip on the structural performance. Analytical stress-slip relationships for different plain rebar anchorage shape are presented, their implementation in a structural model is then suggested. The element non-linear behaviour is lumped at the element end, based on its expected rocking-like behaviour; nevertheless, the model is able to account for the deformation contribution spread along the rebar embedded length, both in the element and in the joint or foundation side. The cyclic behaviour of an anchored plain rebar is also analytically treated; however, to facilitate the representation in a numerical environment, simplified rules are proposed to simulate the effects of reversal and repeated loading. The effectiveness of the model in predicting the response of such type of buildings is proved by simulating tests on columns, beam-column joints, and an entire frame, taken from literature. The structural elastic response is well captured, as well as the energy dissipation during cycling loading. The assessed secant stiffness at yielding is found to be significantly lower with respect to the prediction obtained without the consideration of smooth bar slip; in other words, with respect to the stiffness assessed for an element with deformed reinforcement. The results are particularly significant for range of drift demand within 1.50% and help a comprehensive design and assessment of seismic retrofit of existing buildings, since the modelling approach allow a reliable prediction of the triggering of brittle mechanisms
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
CH.15 Testing of bond for corroded reinforced concrete specimens
No full textThe aim of this study is the proposal of guidelines for bond tests on corroded specimens.
A database of tests collected from the literature is reported. The different types of tests are
described. The effects of accelerated corrosion tests are discussed, in relation to the different
rates imposed experimentally, with the residual bond strength and the development of
pressure with corrosion product expansion. A limit on the maximum rate that can be used
in tests proposed in studies in the literature is highlighted. The more appropriate types of
tests are discussed, with the necessary measurements and techniques
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