1,721,018 research outputs found
Performance and power smoothing of innovative closed-circuit oscillating water column wave energy converter
Get PDFDue to the urgency to limit global warming to 1.5◦C, it is necessity to find alternatives to fossil fuel energy to empower human activities. Among the alternative resources of energy, wave energy has a large potential as it could potentially represent 10% of the world electricity demand. Significant progress in this field is however still needed to produce affordable electrical energy. Oscillating-Water-Column (OWC) devices are among the most promising types of wave energy converters because of their relative simplicity. The present work investigates the possibility of improving the performance of this well-established concept by introducing a variation in the working principle. The resulting new Tupperwave concept is equipped with non-return valves and air pressure accumulators to create a smooth unidirectional air flow, harnessed efficiently by a unidirectional turbine. In this thesis, the Tupperwave concept is investigated physically and numerically on a floating structure. In order to assess the relevance of the Tupperwave device against the conventional OWC, wave-to-wire numerical models for both devices are developed, using different thermodynamic approaches and considering the use of the current state-of-the-art turbines for each device. The different power conversion processes of the wave-to-wire models are validated through physical experiments. The wave-to-wire models are then used to identify the benefits of pneumatic power smoothing by the Tupperwave device and assess its electrical power performance. The results demonstrate the potential of the new Tupperwave concept to outperform the conventional OWC concept in terms of electrical power production and quality
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
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
Motion and performance of BBDB OWC wave energy converters: I, hydrodynamics
Get PDFThe Backward Bent Duct Buoy (BBDB) oscillating water column (OWC) wave energy converter (WEC) has been invented following the so-far most successful OWC navigation buoys in wave energy utilisation, with aims to build large and efficient OWC wave energy converters for massive wave energy production. The BBDB device could use its multiple motion modes to enhance wave energy conversion, however, the mechanism of the motion coupling and their contributions to wave energy conversion have not been well understood in a systematic manner. In particular, the numerical modelling has been very limited in exploring how these motions are coupled and how the wave energy conversion capacity can be improved. As in this part of the research of a systematic study using numerical modelling, focus is on the understanding of the hydrodynamic performance for the BBDB OWC wave energy converter. In the study, the boundary element method based on potential flow theory has been applied to calculate the basic hydrodynamic parameters for the floating BBDB OWC structure and the water body in the water column in the BBDB OWC device. With the calculated hydrodynamic parameters and the decoupled and coupled models for the BBDB OWC dynamics, it is possible to examine these hydrodynamic parameters in details and to understand how they interact each other and how they contribute to the relative internal water surface motion, a most important response in terms of wave energy conversion of the OWC devices. All these will provide a solid base for further studying the power performance of the BBDB devices for converting energy from waves as shown in the second part of the research
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
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
CFD simulations in support of wind tunnel testing
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