1,720,993 research outputs found
Pengaruh Variasi Fraksi Massa Komposit Hibrid Serat Goni/E-Glass Terhadap Kekuatan Tarik Dan Kekuatan Bending
Full text linkMaterial komposit menjadi pilihan utama dalam berbagai sektor industri karena keunggulannya yang ringan, tahan korosi, dan memiliki kekuatan mekanik tinggi dibanding logam konvensional. Salah satu pengembangan komposit adalah pemanfaatan serat alami dan serat sintetis dalam pembuatan komposit hibrid. Penelitian ini bertujuan untuk mengetahui pengaruh variasi fraksi massa komposit hibrid serat goni/e-glass terhadap kekuatan tarik dan kekuatan bending. Spesimen dibuat menggunakan metode hand lay up dengan variasi fraksi massa serat goni/e-glass yaitu A (19%:11%), B (12%:18%), C (15%:15%), dan D (23%:7%). Uji tarik dan bending dilakukan masing-masing sesuai standar ASTM D638 dan D790. Hasil pengujian tarik menunjukkan bahwa spesimen B memiliki nilai tegangan tarik dan modulus elastisitas tertinggi sebesar 117,199 MPa dan 3881,312 MPa, namun memiliki regangan tarik yang lebih rendah yang menandakan sifat material tersebut lebih getas. Sementara itu, hasil uji bending menunjukkan bahwa spesimen A menghasilkan tegangan bending dan modulus elastisitas bending tertinggi sebesar 41,106 MPa dan 689,987 MPa. Analisis makro mengungkapkan adanya kegagalan delaminasi, fiber breaking, void, dan deformasi pada patahan spesimen. Semua spesimen telah memenuhi standar minimal kekuatan tarik untuk bahan outer helm SNI. Secara keseluruhan, komposisi fraksi massa serat dan penempatan susunan serat berpengaruh signifikan terhadap sifat mekanik komposit hibrid ini
Is There a Role for Probiotics in Helicobacter pylori Therapy?
No full textThe role of probiotics in Helicobacter pylori therapy remains unclear. Lactobacilli can be shown to inhibit H pylori in vitro. Some strains of Lactobacilli may exert specific antimicrobial effects. There is no strong evidence of a benefit on eradication rate when probiotics are added to a regimen. Despite promising results obtained using compounds of L reuteri and S boulardii, high-quality trials are needed to define the role of probiotics as adjuvant therapy. Variables that remain to be studied with L reuteri, currently the most promising strain, include dosage, frequency of administration, administration in relation to meals, and duration of therapy
Helicobacter pylori and Nonmalignant Diseases
No full textPeptic ulcer bleeding and recurrence rate are strongly linked to Helicobacter pylori infection even if nonsteroidal anti-inflammatory drugs (NSAIDs) play a relevant role in this setting. Further studies confirm that H. pylori eradication lowers the risk of recurrent peptic ulcer bleeding. Therefore, a test-and-treat strategy appears to be mandatory for patients with a history of ulcer bleeding and NSAIDs and/or aspirin use. Concerning gastroesophageal reflux disease (GERD), evidence clearly shows that H. pylori status has no effect on symptoms and treatment. Therefore, H. pylori treatment is not contraindicated in patients with GERD. The exact role of H. pylori in functional dyspepsia (FD) remains controversial. Novel possible mechanisms by which H. pylori may elicit dyspeptic symptoms include alterations of gastric motility, as well as endocrine and acid-secretory abnormalities. Hunger sensations, acid secretion, and gastrointestinal motility are regulated by ghrelin, particularly produced by the gastric enteroendocrine cell compartment. The improvement of symptoms correlates with enhanced plasma ghrelin levels. Apart from the need for more trials on this topic, these findings may give insight into the underlying pathophysiology of FD symptoms. Recent reports suggest that the presence of bacterial DNA in the oral cavity may be relevant to its transmission. A potential protective role of H. pylori on inflammatory bowel diseases needs to be better elucidated. © 2014 John Wiley & Sons Ltd
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
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