1,721,085 research outputs found
Analysis and Design of the Additive Manufacturing Process for Artificial Cornea
No full text角膜是位於眼球最外圍一種無血管且高度透明之組織，但角膜因受傷，感染，或病變而造成白化或是透光度下降問題，全球有超過上千萬人因角膜問題而失明。鑒於由全球捐贈者提供的角膜數量不足，以及接受角膜移植手術後病患可能產生的排斥現象，人工角膜成為目前具有極高潛力的取代方案。積層製造可配合客製化生產組織結構，提供了可替代天然組織的成品。本研究藉此提出以積層製造之技術，透過列印的技術製造人工角膜。利用積層製造的優點，可製作出客製化形狀的人工角膜。本研究針對利用積層製造方式製造角膜的製程進行設計及評估，使用了COMSOL軟體模擬製程中角膜的形變；以及利用3D列印時，配合精確的溫度及壓力控制，成功製造角膜結構及對可交聯之具有丙烯酸官能基的高分子泊洛沙姆水膠 (P407DA) 進行光固化。透過改變環境溫度於15°C與添加支撐氣壓，以此積層製造方法所製造出的人工眼角膜，具有光滑清澈的表面，且於可見光波段具有82%以上的透光度。The cornea is the outermost part of the eye and a highly transparent organization without vessels. However, due to injury, infection or disease, the cornea can cause bleaching or transmittance decline. In the worldwide, more than millions people are blind due to corneal problems. The global need for artificial cornea is driven by both the population that cannot tolerate donor corneas and the severe shortage of donor corneas. Additive manufacturing provides the opportunity to produce substitutes of the native tissues, and, in turn, to produce customized tissue constructs. This study aims to analyze and design various additive manufacturing processes for artificial cornea. COMSOL simulation presents the deformation of the corneal structure during fabrication. Moreover, 3D printing enables accurate temperature and pressure control in construction on corneal structure during dispensing and photo-curing of diacrylate-terminated Poloxamer 407 (P407DA) hydrogel. With the precise control at ambient temperature (15°C) and additional air pressure support (45 Pa), fabricated corneas can be formed with a smooth surface and light transmission all over 82% in the range of visible light by additive manufacturing process
Heat transfer from the pipe wall to flowing gas-solid plugs for non-invasive mass flow measurement based on a thermal method
No full textThermal flowmeters based on a heat transfer principle can, in principle, provide direct mass flow measurement of gas-solids two-phase flow. The development of a thermal mass flowmeter for gas-solid two-phase flow will inevitably involve a study of how to describe, analyze and assess the dynamic characteristics of the gas-solids two-phase flow with heat transfer. A non-invasive thermal system has been proposed. The key issues have been highlighted and the results from initial simulations and measurements have indicated that the technique is worthy of further and more detailed investigation. However, such investigation is complex as many variables exist which directly affect the response of a solids' flow instrument. There are several key issues that have to be accounted for, including: (i) direct and non-invasive temperature measurement; (ii) heat transfer from the hot pipe wall to the flowing gas-solid plug; (iii) short measuring time. Many researchers have reported experiments and simulations of heat transfer of gas-solids two-phase flows in a conveying pipeline, but so far little has been presented on the heat transfer from the hot pipe wall to the flowing gas-solid plug, which is the subject of the present study. This paper concentrates on: (i) the heat transfer from the hot wall to the gas-particles dense flow at different solids loading ratio; (ii) average heat transfer coefficient.</p
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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