1,720,954 research outputs found
An investigation into the keying behaviour and the capacity of plate anchors in sand
No full textThis thesis considers the potential of plate anchors as an anchoring option for offshore renewable energy devices such as wave energy converters and floating offshore wind turbines. In this study the performance of a plate anchor vertically installed in sand and subjected to vertical loading has been investigated experimentally. Particular focus was placed on the unrecoverable loss of embedment during the keying process, where the orientation of the plate evolves from vertical to perpendicular to the direction of loading. This is particularly significant for offshore plate anchors as an unrecoverable loss in anchor embedment corresponds with a loss in potential anchor capacity. The loss in embedment during keying was examined for six anchors, all with the same plate geometry, but with anchor padeyes (or load attachment points) that were at differing eccentricities from the plate.\ud
The experiments were conducted at model scale using the geotechnical centrifuge at the Institute of Technology Sligo. To facilitate observation of the anchor orientation and quantification of the loss in embedment during the test, anchor tests were conducted adjacent to a Perspex panel on the centrifuge strongbox. Vertical loading was achieved by pulling a mooring line attached to the anchor padeye at a constant velocity. The location and orientation of the anchor during each anchor test was captured using a high resolution digital camera mounted directly in front of the Perspex panel.\ud
The experimental data show that the loss in embedment of the plate anchor during keying is inversely proportional to the padeye eccentricity, with a padeye eccentricity equal to at least the breadth of the anchor plate giving minimal loss in embedment and hence highest potential anchor capacity. The magnitude of the loss in embedment is very similar to previous findings for clay.\ud
The peak anchor capacity was observed before the end of keying, at a plate orientation between 50 and 80 degrees to the horizontal. Particle image velocimetry was employed to reveal the failure mechanisms during the keying process. These analyses showed that the peak load corresponds with a sudden transition from a deep localised failure mechanism to a shallow mechanism that extends to the soil surface.\ud
The anchor capacity, expressed in terms of a dimensionless capacity factor, was shown to be in good agreement with previously reported experimental data on pipelines and strip anchors, but only after the peak anchor capacity is exceeded and the anchor behaves like a horizontally oriented anchor subjected to vertical loading. The particle image velocimetry analyses show that the inclination of the slip planes in the shallow failure mechanism are at an angle that is much lower than would be reasonable for a mobilised friction angle. This clearly shows that the normality condition, in which the dilation angle and the friction angle are equal, was not met in these tests and explains why the experimental data are in good agreement with predictions from a limit equilibrium method based on similar principles
An investigation into the keying behaviour and the capacity of plate anchors in sand
No full textThis thesis considers the potential of plate anchors as an anchoring option for offshore renewable energy devices such as wave energy converters and floating offshore wind turbines. In this study the performance of a plate anchor vertically installed in sand and subjected to vertical loading has been investigated experimentally. Particular focus was placed on the unrecoverable loss of embedment during the keying process, where the orientation of the plate evolves from vertical to perpendicular to the direction of loading. This is particularly significant for offshore plate anchors as an unrecoverable loss in anchor embedment corresponds with a loss in potential anchor capacity. The loss in embedment during keying was examined for six anchors, all with the same plate geometry, but with anchor padeyes (or load attachment points) that were at differing eccentricities from the plate.
The experiments were conducted at model scale using the geotechnical centrifuge at the Institute of Technology Sligo. To facilitate observation of the anchor orientation and quantification of the loss in embedment during the test, anchor tests were conducted adjacent to a Perspex panel on the centrifuge strongbox. Vertical loading was achieved by pulling a mooring line attached to the anchor padeye at a constant velocity. The location and orientation of the anchor during each anchor test was captured using a high resolution digital camera mounted directly in front of the Perspex panel.
The experimental data show that the loss in embedment of the plate anchor during keying is inversely proportional to the padeye eccentricity, with a padeye eccentricity equal to at least the breadth of the anchor plate giving minimal loss in embedment and hence highest potential anchor capacity. The magnitude of the loss in embedment is very similar to previous findings for clay.
The peak anchor capacity was observed before the end of keying, at a plate orientation between 50 and 80 degrees to the horizontal. Particle image velocimetry was employed to reveal the failure mechanisms during the keying process. These analyses showed that the peak load corresponds with a sudden transition from a deep localised failure mechanism to a shallow mechanism that extends to the soil surface.
The anchor capacity, expressed in terms of a dimensionless capacity factor, was shown to be in good agreement with previously reported experimental data on pipelines and strip anchors, but only after the peak anchor capacity is exceeded and the anchor behaves like a horizontally oriented anchor subjected to vertical loading. The particle image velocimetry analyses show that the inclination of the slip planes in the shallow failure mechanism are at an angle that is much lower than would be reasonable for a mobilised friction angle. This clearly shows that the normality condition, in which the dilation angle and the friction angle are equal, was not met in these tests and explains why the experimental data are in good agreement with predictions from a limit equilibrium method based on similar principles
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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
No full textWe 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
No full textWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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