1,720,960 research outputs found
Impacto de la variabilidad climática y el cambio climático sobre el potencial eólico en América del Sur.
No full textTesis presentada para optar al grado de Doctor/a en Energías.La energía eólica terrestre es una de las fuentes renovables con mayor participación en la matriz energética global. Sin embargo, las redes eléctricas están cada vez más expuestas a su variabilidad intrínseca. Este trabajo evalúa la influencia de diferentes patrones atmosféricos de gran escala sobre la variabilidad de la velocidad viento a 100m (WS100) y la densidad del potencial eólico (WPD) en América del Sur, y su impacto sobre la producción anual de energía (AEP) en el futuro. Se utilizaron datos de 14 modelos climáticos globales de CMIP6 y de reanálisis del ERA5 para el período histórico 1980 - 2014 y los períodos futuros 2030 – 2069 y 2070 – 2099 bajo el escenario SSP2-4.5. Se aplicó un análisis de funciones ortogonales empíricas (EOF) sobre WS100 en regiones seleccionadas y se calcularon las correlaciones con los principales patrones atmosféricos que influyen sobre el clima de la región. Se calcularon las variaciones de WPD con respecto al período histórico y se estimaron las diferencias futuras de AEP en las regiones más impactadas.
Según nuestros resultados los principales cambios en WPD y AEP se concentran en dos regiones fundamentales: el nordeste de Brasil y la Patagonia. Encontramos que el Anticiclón del Atlántico Sur (SAA) es el principal modulador de WS100 sobre el nordeste de Brasil dado por una correlación positiva, por lo que el aumento en la intensidad del SAA provoca un aumento de WS100 en dicha región. Por otra parte, descubrimos un patrón al que denominamos Patrón Patagonia - Antártica (PAT), y que constituye el principal modulador de WS100 sobre la Patagonia, dado por una correlación negativa, por lo que la fase positiva del PAT provoca una disminución de WS100.
Se prevé un aumento significativo de WPD de más del 30% para 2099 en el nordeste de Brasil, asociado principalmente a una tendencia positiva del SAA, mientras que se proyecta una disminución de hasta un -20% en la Patagonia asociada a una tendencia positiva en el PAT. Estos cambios equivalen a un aumento de AEP de hasta un 18% para 2069 y un 37,6% para 2099 en el nordeste de Brasil, mientras que en la Patagonia se proyecta una disminución de hasta un -33,6% para 2069 y un -33,8% para 2099. La principal contribución de este trabajo es que permite comprender los mecanismos atmosféricos que influyen en las variaciones a largo plazo de WPD y AEP. Esto es de gran relevancia para la industria eólica en la planificación del sistema y la evaluación de riesgos en proyectos eólicos actuales y futuros en América del Sur.On-shore wind energy is one of the renewable sources with the largest share in the global energy mix. However, electricity grids are increasingly exposed to their intrinsic variability. This work evaluates the influence of different large-scale atmospheric patterns on the variability of 100m wind speed (WS100) and wind power density (WPD) in South America, and their impact on future annual energy production (AEP). Data from 14 CMIP6 global climate models and ERA5 reanalysis were used for the historical period 1980–2014 and the future periods 2030–2069 and 2070–2099 under the SSP2-4.5 scenario. An empirical orthogonal function (EOF) analysis was applied to WS100 in selected regions, and correlations with the main atmospheric patterns influencing the region climate were calculated. WPD variations relating to the historical period were calculated, and future AEP differences were estimated in the most impacted regions.
According to our results, the main changes in WPD and AEP are concentrated in two key regions: northeast Brazil and Patagonia. We found that the South Atlantic Anticyclone (SAA) is the main modulator of WS100 over northeast Brazil, with a direct relationship, such that an increase in SAA intensity causes an increase in WS100 and vice versa. We discovered a pattern centered in the Drake Passage, which we named the Patagonia-Antarctica (PAT) pattern, which constitutes the main modulator of WS100 over Patagonia. The positive phase of the PAT causes a decrease in WS100 and vice versa.
A significant increase in WPD of more than 30% is projected by 2099 in northeast Brazil, mainly associated with a positive SAA trend, while a decrease of up to -20% is projected in Patagonia associated with a positive PAT trend. These changes are equivalent to an AEP increase up to 18% by 2069 and 37.6% by 2099 in Northeast Brazil, while in Patagonia a decrease up to -33.6% by 2069 and -33.8% by 2099 is projected. The main contribution of this work is that it allows an understanding of the atmospheric mechanisms influencing long-term variations in WPD and AEP. This is of great relevance to the wind industry in system planning and risk assessment for current and future wind projects in South America.ANID, Beca de Doctorado Nacional 2021 N°21210309Facultad de IngenieríaDepartamento de GeofísicaConcepció
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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