1,720,961 research outputs found
Experimental and numerical analysis of a backpressure Banki inline turbine for pressure regulation and energy production
Full text linkWater distribution networks have become, in recent years, a major opportunity for the harvesting of renewable energy, which is otherwise dissipated though hydrovalves installed for discharge and pressure regulation. Mini and micro hydroturbines have the capability of providing the same functionality of hydrovalves, producing at the same time a relevant amount of electric power. In this paper a 10 kW prototype of a new compact in-line turbine, named Power Recovery System (PRS), has been designed, constructed and tested in the hydraulic laboratory of the University of Palermo. The proposed device is a Banki-type micro-turbine, with positive outflow pressure and a mobile regulating flap for hydraulic control of the characteristic curve. The device is aimed to control pressure or discharge inside a water transport or distribution network, while producing energy with good efficiency values, up to 76%. Using two pressure meters located immediately before and after the turbine, it is possible to control the net head with given discharge (passive mode) or to control discharge by regulating the net head (active mode). 3D numerical analysis and laboratory measurements provide a low variation of efficiency for different positions of the mobile flap, especially for low variations in discharge
DEVIATORE DI FLUSSO PER TURBINE IDRAULICHE IN LINEA
No full textUn deviatore di flusso per una turbina idraulica a flusso incrociato presenta una
sezione di uscita atta ad essere collegata alla sezione a valle della condotta idraulica
per l’immissione di un flusso in uscita del fluido liquido in pressione con un vettore di velocità di uscita avente modulo di uscita (Vo) e direzione di uscita (do)
predeterminati, un condotto di scarico per il ripristino del vettore velocità di detto
flusso in uscita al modulo in ingresso ed a una direzione di uscita sostanzialmente
parallela o coincidente con detta direzione di ingresso (di), in cui detto deviatore
comprende, un primo settore immediatamente a valle di detta girante ed atto a variare
la direzione del flusso in uscita dalla girante da radiale a tangenziale, un secondo
settore a valle di detto primo settore ed in continuità fluidica con lo stesso ed avente
una prima ed una seconda parete laterale opposte configurate per determinare
un’accelerazione costante del flusso, un terzo settore a valle di detto secondo settore
ed in continuità fluidica con lo stesso ed avente una prima ed una seconda parete
laterale opposte curvilinee ed in continuità rispettivamente con detta prima e detta
seconda parete laterale di detto secondo settore, un quarto settore a valle di detto
terzo settore ed in continuità fluidica con lo stesso ed avente una sezione di uscita in
collegamento con il tratto a valle della condotta per lo scarico del fluido con detta
velocità di uscita, in cui dette prima e seconda pareti laterali di detto terzo settore
comprendono ognuna un primo ed un secondo tratto curvilinei e definenti archi di
cerchio di circonferenze reciprocamente concentriche ed in cui detto primo tratto di
detta prima parete laterale di detto terzo settore e detta prima parete laterale di detto
secondo settore definiscono un arco di cerchio di una stessa circonferenza avente un
primo raggio (Rp) predeterminato
Combined GPR and seismic refraction tomography to study the subsoil in the Cathedral of S. Giorgio Ragusa- Ibla (Sicily)
No full textIn this work, we show GPR surveys combined with a series of seismic refraction tomographies to study the subsoil in the Cathedral of S. Giorgio in Ragusa Ibla (Sicily). The church stands on a high structural level characterized by a carbonate formation, consisting of a calcarenite-marly succession. Built in the 18th century, where previously stood the church of San Nicola, the new building probably hosts, under the present flooring, several tombs of different ages and probable remains of the oldest previous church. The combination of the two geophysical methods here proposed allows us to highlight the potential of each technique and how they perfectly support the reconstruction of the subsoil of the church with different details on archaeological and geological/structural buried structures
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
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