1,720,953 research outputs found
Development of biodegradable Mg-1Zn-0.5Sc alloy & Surface treatment through Laser Shock Peening and Evaluation of Microstructure & Property correlation for Orthopedic Implants
No full textMagnesium (Mg) and its alloys are of much interest as promising third-generation bio-materials for bone implant applications; however, challenges remain for the alloy\u27s mechanical integrity and bio-corrosion behaviour. Therefore, appropriate alloying elements and surface-modification techniques are required to overcome these limitations. Zinc (Zn) and Scandium (Sc) elements were found to have good biocompatibility and biodegradability; hence, they were selected as suitable alloying elements for magnesium.
This research work aims to enhance the mechanical integrity and bio-corrosion resistance behaviour of a novel Mg-1wt% Zn-0.5wt% Sc cast alloy by laser shock peening surface treatment with multiple passes (LSP-2 Pass and LSP-3 Pass). Based on the characterization studies, LSP induced beneficial compressive residual stress around the surface and sub-surface region of Mg-1Zn-0.5Sc alloy due to severe plastic deformation, which led to grain refinement through the twinning mechanism of the Mg alloy.
Also, the dispersion of second-phase particles (β-ScZn) was observed while analysing the XRD profiles. Strain hardening and grain refinement have been attributed to the evolution of structure and texture, which enhanced the strength, ductility, and corrosion resistance of novel Mg-1Zn-0.5Sc alloy compared to the as-cast condition. From in vitro studies, a low rate of corrosion in simulated body fluid, uniform hydroxyapatite layer formation on the surface and less cytotoxic behaviour was observed for the LSP-3 pass Mg-1Zn-0.5Sc alloy, which is suitable for bone implant applications.
However, some limitations remain, and challenges need to be addressed. In the LSP-3 pass, Mg material had only a marginal strength and a corrosion rate of cortical bone properties for orthopaedic implant applications. To address these challenges, Mg-1Zn-0.5Sc alloy was developed through thermomechanical processing at various temperatures.
During extrusion at 250°C and 350°C, the microstructure and texture evolution of the hot extruded at 350°C alloy exhibited complete dynamic recrystallization, and texture evolved to strong basal plane orientation, influencing an increased strength of 152 MPa, reduced ductility of 10%, and improved corrosion resistance. Moreover, this hot extruded at 350°C processed Mg alloy underwent multipass laser shock peening surface treatment to synergistically enhance its strength and ductility properties via structural and textural evolution.
Hence, laser shock peening on this extruded alloy surface leads to further recrystallizations owing to the effect of developed compressive residual stress near the peened surface, resulting in large grain formation. Also, favourable texture evolution of basal and non-basal planes was observed due to this LSP-induced plastic strain, with significant improvement in strength and ductility to 230MPa and 16%, respectively.
Biocompatibility analysis shows that both extruded and LSP-treated alloys have uniform bio-friendly hydroxyapatite layer formation and exhibit good cell viability after 72h of incubation. It also shows a reduced corrosion rate compared to the as-cast alloy, which can also harmonize with tissue healing and implant degradation. The extruded Mg alloy was developed through the LSP technique and can be a candidate material for orthopaedic implant application
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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