1,720,953 research outputs found
EVALUATION OF INFILTRATION SWALE MEDIA USING SMALL- AND INTERMEDIATE-SCALE TESTING TECHNIQUES
Get PDFWhen impervious surfaces such as paved roadways are constructed, the volume of water infiltrating into native soil decreases, leading to an increase in surface water runoff. This phenomenon results in higher peak flows, elevated erosion rates, and the transport of total suspended solids and pollutants. Hydrocarbons and other pollutants from paved surfaces find their way into receiving water bodies, posing environmental challenges. Regulations mandate water runoff control to minimize erosion and prevent sediment deposition. Low impact development (LID) practices aim to maintain the pre-development hydrological cycle through processes including evapotranspiration, infiltration, water reuse, and filtration. The Alabama Department of Transportation (ALDOT) relies on implementing infiltration swales, a type of LID practice, alongside roadways to manage water runoff quantity. These practices function by promoting surface water runoff to enter through an engineered media within roadside channels. By having a high permeability rate, the media serves to promote groundwater infiltration. Currently, ALDOT infiltration swale media is made up of a matrix consisting of topsoil, sand, and No. 57 stone wrapped with geotextile. Infiltration swales have been used throughout the state by ALDOT, however, their performance has not been evaluated and thus research is needed to understand how this standard media performs and to optimize its performance.
The purpose of this research was to design a methodology for evaluating and optimizing the performance of infiltration swale media. Testing methodologies and apparatuses were developed to assess their capacity to infiltrate water on a small and intermediate scale. Three types of apparatuses were built for this research: a permeameters structure, consisting of 18 permeameters with a diameter of 6 in. (15.2 cm) and a length of 3.0 ft (0.9 m), a clear infiltrometers structure, consisting of six infiltrometers with a diameter of 6 in. (15.2 cm) and a length of 3.0 ft (0.9 m), and an infiltration swale chamber, monitored by a moisture content system, with internal dimensions measuring 8.0 ft (2.4 m) in length, 2.5 ft (0.8 m) in width, and 4.0 ft (1.2 m) in height. Constant head permeability tests conducted on the permeameters revealed that the current ALDOT infiltration swale media design yields a very low permeability ranging from 0.0017 in./min (0.0043 cm/min) to 0.019 in./min (0.0495 cm/min). This is attributed to the low permeability of the topsoil, which yielded 0.002 in./min (0.004 cm/min).
As a result, designs containing topsoil as the top layer could not achieve the minimum infiltration rate of 1.0 ft/day (0.38 m/day) required by the Alabama LID Manual. To improve the infiltration rate through the topsoil layer, alternatives with amended materials were investigated. Several mixtures of amended topsoil, consisting of topsoil and pine bark fines at different proportions, underwent falling head infiltration rate tests. The amended topsoil mixture containing 80% topsoil and 20% pine bark was selected as the top layer for future alternative designs because it yielded an average infiltration rate under falling head conditions of 5.6 ft/day (1.6 m/day), 8.8 times higher than topsoil alone, which yielded 0.63 ft/day (0.19 m/day).
Throughout the process, the testing methodology to evaluate the performance of infiltration swale media design in the infiltrometers was refined to establish a consistent testing regimen comprising three constant head infiltration tests lasting six hours each, followed by three falling head infiltration tests. Constant head infiltration tests simulated the prolonged use of infiltration swale media, providing insights into their long-term performance. Falling head infiltration tests allowed for understanding the time required by the designs to infiltrate the ponding water, enabling comparisons of their performances with the minimum required infiltration rate of 1 ft/day (0.38 m/day). Initially, five infiltration swale media designs were proposed and subjected to this testing regimen. In an iterative cycle of evaluation and improvement, the results of previous tests were analyzed to identify causes of low performance and potential enhancement options. During this testing and optimization process, it was evident that designs including a geotextile layer wrapped up around the No. 57 stone exhibited a continuous decrease in their infiltration rate due to the gradual clogging of geotextile pores by sand particles. This cycle of evaluation and improvement was iteratively repeated until finally achieving the F3 design, composed of 6 in. (15.2 cm) height of amended topsoil (80% topsoil and 20% pine bark fines by weight), 10 in. (25.4 cm) height of field sand, 6 in. (15.2 cm) height of pea gravel, and 9 in. (22.9 cm) height of #57 stone. The F3 design exhibited a performance of 13.73 ft/day (4.18 m/day) in constant head infiltration tests, 15.1 times higher than the 0.91 ft/day (0.28 m/day) obtained by the ALDOT standard matrix, and 11.66 ft/day (3.55 m/day) in falling head infiltration tests, 37.61 times higher than the 0.31 ft/day (0.09 m/day) obtained by the ALDOT standard matrix.
Finally, the ALDOT and the F3 design were tested in the infiltration swale chamber under constant and falling head conditions. The F3 design yielded 87.06 ft/day (26.54 m/day) in constant head conditions, 13.37 times higher than the 6.51 ft/day (1.98 m/day) yielded by the ALDOT design, and 75.79 ft/day (23.20 m/day) in falling head conditions, 15.28 times higher than the 4.96 ft/day (1.51 m/day) yielded by the ALDOT standard matrix. The tests conducted in the infiltration swale chamber were monitored by a moisture content system, showing that the F3 design has a drying rate 111 times higher than the ALDOT design. The results of this research showed that with the F3 design, infiltration swales will achieve higher infiltration rates in the short and long term, as well as superior drying rates, leading to a larger available storage volume after each rainfall event. The F3 design and the ALDOT design will be evaluated on a field-scale by the Auburn Stormwater team, and the results will be compared with those obtained in this research
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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