1,720,989 research outputs found
Addressing agricultural pressures on water resources: a DEA environmental assessment in the case of european transboundary basins
Get PDFTurbulence convective heat transfer for cooling the photovoltaic cells
Get PDFSolar PV (photovoltaic) is a rapidly advancing renewable energy technology which converts sunlight directly into electricity. One of the outstanding challenges of the current PV technology is the reduction in its conversion efficiency with increasing PV panel temperature, which is closely associated with the increase in solar intensity and the ambient temperature surrounding the PV panels. To more effectively capture the available energy when the sun is most intense, significant efforts have been invested in active and passive cooling research over the last few years. While integrated cooling systems can lead to the highest total efficiencies, they are usually neither the most feasible nor the most cost effective solutions. This work examines some simple passive means of manipulating the prevailing wind turbulence to enhance convective heat transfer over a heated plate in a wind tunnel
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
Vortex Induced Convective Heat Transfer Augmentation
Get PDFDelta winglet is an effective means to passively augment heat convection from a hot surface such as a solar panel. The effects of an inclination angle on the flow downstream of the winglet were studied. A delta winglet with an aspect ratio (c/h) of 2 and an attack angle of 30 degrees was mounted on a flat plate to scrutinize the role of its inclination angle (90° and 120°) on the flow downstream. The inclined winglet was placed in a wind tunnel, and the flow was measured by the hotwire. The experiment shows the 120-degree-inclination-angle delta winglet can generate an inflow velocity larger than 90 degrees. The heat transfer enhancement caused by the delta winglet was then investigated. Three different inclination angles (60°, 90° and 120°) of the delta winglet were studied, and a thermal camera was used to maintain the heat transfer enhancement of the heated panel. The result shows that the delta winglet with the inclination angle of 120 degrees can generate the best thermal performance
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
A study of the turbulence generated behind a perforated plate in a wind tunnel.
No full textConventionally, grids composed of bars or stripes have been used to a great extent in the experimental studies of isotropic turbulence. Perforated plates are utilized instead of grids in the present study. A perforated plate was placed at the entrance of the test section of a wind tunnel. The turbulent flow downstream of the plate was measured using a constant temperature hot-wire anemometer in conjunction with a single normal and a single inclined hot-wire. Measurements were conducted for nine different operating conditions which consisted of planes at three downstream distances and three flow rates. Each plane contained eighty-one measuring locations. At each location, three measurements were taken, one with the single normal hot-wire probe, the other two with the single inclined hot-wire probe. Nine different plates were tested. The total number of measurements was 19,683. The signal from single normal hot-wire probe was processed to obtain the turbulence root mean square (rms) velocity in the streamwise direction, u '. The turbulence integral length scale based on the Taylor's frozen turbulence hypothesis was obtained from the signal of single normal probe. The turbulence rms velocity in the lateral direction, v ', was obtained by combining u' with the processed result from the single inclined probe. (Abstract shortened by UMI.)Dept. of Mechanical, Automotive, and Materials Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2002 .L57. Source: Masters Abstracts International, Volume: 41-04, page: 1181. Advisers: David S-K. Ting; Gary W. Rankin. Thesis (M.A.Sc.)--University of Windsor (Canada), 2002
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