1,721,000 research outputs found
COMPARATIVE ANALYSIS OF TWO-PHASE THERMOSYPHONS SOLAR COLLECTORS
No full textThis paper deals with two-phase thermosyphons used in glazed flat plate solar collectors. It analyses the performance of thermosyphons solar collectors by means of a steady-state mathematical model based on the lumped capacitance method. The model simulates the thermal behaviour of a single tube and of the whole collector at various operating conditions.
The present mathematical model has been validated experimentally using data taken on a copper thermosyphon. A test section has been set up, which is made of a single ended copper thermosyphon, where the input power at the evaporator is supplied by an electrical heater.
The validated model is finally applied to an analysis of two-phase thermosyphons solar collectors with variable configuration
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
Chromosome mapping of the sweet potato little leaf phytoplasma reveals genome heterogeneity within the phytoplasmas
No full textVaporization heat transfer in a closed two-phase thermosyphon
No full textThis paper deals with heat transfer in a closed two-phase thermosyphon with a long evaporator and a short condenser, filled with water as operating fluid. The ratio of length to inside diameter of the evaporator is equal to 166. A similar geometry is commonly used in vacuumed tube solar collectors. In the present investigation the input power to the evaporator is provided by means of an electrical resistance wire wrapped around the external wall of the tube, while a water jacket is built at the condenser to reject the heat. An adiabatic section, placed between evaporator and condenser, is used to measure the saturation temperature. The thermosyphon is fully instrumented with thermocouples to measure the wall temperature in the different sections of the tube. The overall performance of the thermosyphon is described by using the wall temperature and overall thermal resistance for different operating conditions: input power at the evaporator, cooling water temperature at the condenser and inclination of the thermosyphon (30°, 60° and 90° tilt angle to the horizontal plane). The experimental study is focused on the evaporator: data of heat transfer coefficient are reported, covering a range of heat flux between 1700 and 8000 W/m2 and saturation temperature between 29 °C and 72 °C. The measured vaporization heat transfer coefficients are compared with some correlations for closed two-phase thermosyphons. A new correlation is presented, which accurately predicts the present experimental heat transfer coefficients and other data by independent labs taken in closed two-phase thermosyphons, with different geometries and operating fluids (water and R134a)
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
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