1,720,999 research outputs found
Análisis y evaluación del uso de turbinas para la recuperación de energía en redes hidráulicas a presión
Get PDFEsta tesis tiene como objetivo evaluar la posibilidad de utilizar la energía hidráulica no
aprovechada en sistemas urbanos de distribución de agua. Para ello, se ha estudiado y
evaluado la viabilidad y las posibles alternativas de instalar turbinas convencionales y/o
bombas que funcionen como turbinas (Pumps as Turbines, PATs) en la cabecera de las
redes hidráulicas a presión en tres localidades de la provincia de Huelva. La Puebla de
Guzmán, Cañaveral de León y Aracena (Andalucía, suroeste de España). Se han
realizado análisis de sensibilidad para la selección de las mejores alternativas
considerando las siguientes etapas: (a) Estudio de la viabilidad y eficiencia de la
instalación de turbinas y/o PATs en las redes hidráulicas; (b) Determinación de la
capacidad hidráulica requerida de las turbinas y/o PATs; (c) Caracterización y
evaluación de los puntos óptimos para la instalación en las redes hidráulicas en estudio;
y (d) Valoración hidráulica y económica de la posible generación de energía eléctrica.
La evaluación de la cantidad recuperable de energía hidráulica en los sistemas de
distribución de agua requiere de la aplicación de la ecuación de conservación de
energía, considerando la ecuación de Darcy-Weisbach para el cálculo de las pérdidas de
carga. Un diagrama de altura de energía-caudal con diferentes rangos de trabajo de
turbinas y PATs comerciales se ha elaborado para la selección de la máquina hidráulica
adecuada. Los resultados obtenidos en la red hidráulica de Aracena muestran que la
mejor solución sería la instalación de una turbina BANKI de 2 kW, que podría generar
una energía anual aproximada de 17,52 MWh/año. En el sistema de abastecimiento de
agua de Cañaveral de León, se propone colocar, una turbina BANKI de 0,75 kW con
una posible generación de energía de 6,57 MWh/año. En el caso de La Puebla de
Guzmán, los resultados muestran diferentes posibles ubicaciones de instalación de una
turbina Francis, que podría llegar a generar una energía de 280 MWh/año. Por otra parte, se ha diseñado y desarrollado un programa de ordenador, utilizando el
lenguaje JAVA, que integra la metodología desarrollada y permite poder calcular de
forma automática el tipo y la capacidad hidráulica de las turbinas y/o PATs que podrían
instalarse considerando los condicionantes y las restricciones hidráulicas de un sistema
de distribución de agua específico. Además, esta aplicación proporciona cuánta energía
anual se podría recuperar de la red hidráulica a presión. Para dicho cálculo el programa
tiene en cuenta las horas diarias de funcionamiento de la turbina y/o PATs que se
pretende colocar. El programa permite dos opciones de cálculo. Para la primera opción,
y más sencilla, solo es necesario introducir como variables de entrada el caudal y la
altura neta disponibles, así como las horas previstas de funcionamiento de la máquina
hidráulica. La segunda opción se debe utilizar cuando no se conoce la altura neta
disponible de energía en la red hidráulica. En este caso, el programa calcula las pérdidas
de carga para calcular, a partir de la altura bruta de energía disponible, la altura neta. En
este caso, las variables de entrada al programa son: el caudal, la altura bruta de energía y
las características de las conducciones (diámetro, longitud y material).This thesis aims to evaluate the possibility of using unused hydraulic energy in urban
water distribution systems, and reusing energy in urban water distribution systems. For
this purpose, the feasibility and possible alternatives of installing conventional turbines
and / or pumps that function as turbines (PATs = Pumps as Turbines) at the head of
pressure hydraulic networks in three locations in the province of Huelva have been
studied and evaluated. These are La Puebla de Guzmán, Cañaveral de León and
Aracena (Andalusia, southwestern Spain). Sensitivity analises have been carried out in
order to select the best alternatives taking the following stages into account: (a) Study of
the viability and efficiency of the installation of turbines and / or PATs in hydraulic
networks; (b) Determination of the required hydraulic capacity of the turbines and / or
PATs; (c) Characterization and evaluation of the optimal points for installation in the
hydraulic networks under study; and (d) Hydraulic and economic evaluation of the
possible generation of electrical energy.
The evaluation of the recoverable amount of hydraulic energy in water distribution
systems requires the application of the energy conservation equation, taking into
account the Darcy-Weisbach equation for the calculation of head losses. An energy flow head diagram with different working ranges of turbines and commercial PATs has
been prepared for the selection of the suitable hydraulic machine. The results obtained
in the Aracena hydraulic network show that the best solution would be the installation
of a 2 kW BANKI turbine that could generate an approximate annual energy of 17.52
MWh/year. In the Cañaveral de León water supply system, it is proposed to install a
0.75 kW BANKI turbine with a possible power generation of 6.57 MWh/year. In the
case of La Puebla de Guzmán, the results show different possible installation locations
for a Francis turbine, which could generate energy of 280 MWh/year.
On the other hand, a computer program has been designed and developed, using the
JAVA language, which integrates the methodology developed and allows us to
automatically calculate the type and hydraulic capacity of the turbines and/or PATs that
could be installed considering the conditions and hydraulic restrictions of a specific
water distribution system. In addition, this application provides how much annual
energy could be recovered from the hydraulic network under pressure. For this
calculation, the program takes into account the daily operating hours of the turbine
and/or PATs to be installed. The program allows two calculation options. For the first
and simpler option, it is only necessary to enter the flow rate and the net head available
as input variables, in addition to the expected hours of operation of the hydraulic
machine. The second option should be used when the net available head of energy in the
hydraulic network is not known. In this case, the program calculates the head losses to
calculate, from the gross head of available energy, the net head. In this case, the input
variables to the program are: the flow, the gross head of energy and the characteristics
of the pipes (diameter, length and material).Ciencias Agroforestale
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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