1,720,963 research outputs found
Studi Eksperimental Pengaruh Pre-Crack Pada Kapasitas Geser Balok Engineered Cementitious Composite Yang Terkorosi
No full textKorosi yang terjadi pada tulangan memiliki pengaruh pada kapasitas lentur maupun geser pada beton bertulang karena adanya kehilangan diameter tulangan. Salah satu penyebab terjadinya korosi adalah munculnya keretakan pada beton. Oleh karena itu dilakukan upaya untuk meminimalkan keretakan yang terjadi yaitu dengan penambahan serat pada beton. Jenis serat yang dibutuhkan adalah serat yang memiliki kuat tarik yang tinggi serta tahan terhadap korosi. Polyvynil alcohol (PVA) merupakan jenis serat memiliki sifat tersebut dan sering digunakan bahan campuran beton. ECC (engineered cementitious composite) berbahan PVA telah terbukti memiliki kapasitas regangan tarik lebih dari 3% dan lebar retakan kurang dari 100 µm, menghasilkan daktilitas tinggi, material yang ramah lingkungan, memiliki koefisien permeabilitas yang rendah, tahan terhadap cuaca panas dan memiliki ketahanan tinggi terhadap korosi. Penelitian ini bertujuan untuk menentukan kapasitas geser pada balok tinggi (deep beam) antara lain: balok normal, balok supplementary (balok dengan penambahan fly ash sebagai bahan pengganti semen) dan balok ECC tanpa pre-crack dengan sengkang, tanpa pre-crack tanpa sengkang serta dengan sengkang dengan pre-crack; jumlah kehilangan massa pada tulangan sengkang maupun tulangan lentur pada balok normal, balok supplementary dan balok ECC setelah korosi; serta besar laju, level dan waktu korosi menggunakan metode galvanostatik. Berdasarkan pengujian geser yang dilakukan maka diketahui balok ECC dengan sengkang memiliki kapasitas beban maksimum 2,32% yang lebih besar dibandingkan balok supplementary dengan sengkang serta 13,10% lebih besar dibandingkan balok normal dengan sengkang. Sedangkan balok ECC tanpa sengkang memiliki kapasitas beban maksimum 1,95% lebih besar dibandingkan balok supplementary tanpa sengkang serta beban maksimum 11,38% lebih besar dibandingkan balok normal tanpa sengkang. Balok ECC setelah terjadi korosi mengalami penurunan kapasitas sebesar 23,72%; balok supplementary 24,59% dan balok normal 25,45%. Jumlah kehilangan massa tulangan geser ϕ8 paling sedikit terdapat pada balok ECC yaitu kurang lebih 2,5 kali lebih sedikit dari balok supplementary dan 5 kali lebih sedikit dari balok normal sedangkan jumlah kehilangan massa tulangan lentur D10 paling sedikit terdapat pada balok ECC yaitu kurang lebih 2,5 kali lebih sedikit dari balok supplementary dan 6 kali lebih sedikit dari balok normal. Selain itu, pada tulangan D10 memiliki laju dan level korosi yang lebih kecil dibandingkan tulangan geser sengkang ϕ8 disertai dengan urutan yang sama yakni balok normal yang terbesar diikuti balok supplementary dan balok ECC. Sedangkan waktu yang dibutuhkan untuk terjadi korosi adalah tulangan lentur D10 lebih lama dibandingkan tulangan geser sengkang ϕ8. Hal ini terjadi karena tebal selimut beton pada tulangan lentur lebih besar yaitu 30 mm dibandingkan dengan tebal selimut beton tulangan sengkang 15 mm.
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The reinforcement corrosion has an influence on flexure and shear capacity due to weight loss of reinforcement diameter. One causes of the corrosion is the appearance of concrete cracks. Therefore an attempt is made to minimize concrete cracks by adding fiber. The type of fiber should has high tensile strength and corrosion resistance. Polyvynil alcohol (PVA) is a type of fiber that has these properties and used as a mixture of concrete. PVA-based ECC (engineered cementitious composite) has been proven that has tensile strain capacity more than 3% and crack widths less than 100 µm, produces high ductility, low permeability coefficient, hot weather resistance and high corrosion resistance. This research aims to determine the shear capacity of deep beam with various type of concrete such as the normal beams, the supplementary beams (the beams with fly ash as cementitious material) and the ECC beams. The shear capacity of the beam was investigated with several configuration such as without pre-crack with stirrups, without pre-crack without stirrup and with pre-crack with stirrups; the mass loss of shear and flexure reinforcements was also investigated. The rate, level and time of corrosion was conducted by galvanostatic method. The shear test result shows that the ECC beam with stirrups has maximum shear capacity 2,23% higher than the supplementary beam with stirrups and 13,10% higher than the normal beam with stirrups. Meanwhile, the ECC beam without stirrup has maximum shear capacity 1,95% higher than the supplementary beam without stirrup and 11,38% higher than the normal beam without stirrup. The ECC beam after corrosion has decreased capacity 23,72%; the supplementary beam 24,59% and the normal beam 25,45%. The least mass loss of shear reinforcement ϕ8 is produced by the ECC beam which is 2,5 times less than the supplementary beam and 5 times less than the normal beam. Meanwhile, the least mass loss of flexure reinforcement D10 is produced by the the ECC beam which is 2,5 times less than the supplementary beam and 6 times less than the normal beam. Furthermore, the flexure reinforcement D10 has the rate and level of corrosion lesser than the shear reinforcement with the same sequence i.e. the most on the normal beam followed by the supplementary beam and the ECC beam. The time of corrosion on flexure reinforcement D10 is longer than shear reinforcement ϕ8 due to concrete cover on flexure reinforcement D10 is 15 cm thicker than shear reinforcement ϕ8
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
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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