1,720,962 research outputs found
Analysis of a Superhydrophobic Microlens Array Surface: As a Microchannel Wall for Pressure Drop Reduction
No full textDesign Strategy for a Piezoelectric Nanogenerator with a Well-Ordered Nanoshell Array
No full textThe piezoelectric nanogenerator (PNG) has been spotlighted as a promising candidate for use as a sustainable power source in wireless system applications. For the further development of PNGs, structural optimization is essential, but the structural analysis progress in this area has been scant. In the present study, we proposed a PNG with a well-ordered nanoshell array structure. The nanoshell structure has been considered as an effective core nanostructure for PNGs due to its effective stress confinement effect but has not been experimentally introduced thus far due to the challenging fabrication method required. To produce a controllable nanoshell structure, a top-down silicon nanofabrication technique which involves advanced spacer lithography is introduced. A comprehensive design strategy to enhance the piezoelectric performance is proposed in terms of the nanoshell diameter and shell-to-shell space. Both simulated and measured data confirm that an extremely high density of a structure is not always the best answer to maximize the performance. The highest amount of power can be achieved when the shell diameter and shell-to-shell space are within their proper ranges. The structural design strategy studied in this work provides a guideline for the further structural developments of PNG
A Polydimethylsiloxane (PDMS) Sponge for the Selective Absorption of Oil from Water
No full textWe present a sugar-templated polydimethylsiloxane (PDMS) sponge for the selective absorption of oil from water. The process for fabricating the PDMS sponge does not require any intricate synthesis processes or equipment and it is not environmentally hazardous, thus promoting potential in environmental applications. The proposed PDMS sponge can be elastically deformed into any shape, and it can be compressed repeatedly in air or liquids without collapsing. Therefore, absorbed oils and organic solvents can be readily removed and reused by simply squeezing the PDMS sponge, enabling excellent recyclability. Furthermore, through appropriately combining various sugar particles, the absorption capacity of the PDMS sponge is favorably optimized
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
동결건조를 이용한 커피링 효과 억제 및 균일한 코팅으로의 응용
No full text학위논문(박사) - 한국과학기술원 : 전기및전자공학부, 2018.8,[1책 :]The coffee-ring effect is the physical phenomenon explaining why the ring-like deposit is left behind along the perimeter of a colloidal drop. It has been renowned as one of the major obstacles in the processes which require homogeneous distribution of dried deposit such as printing or coating. Extensive attempts have been made to suppress this phenomenon, and the most general approach of these is to alter the flow to circulate, thereby redistributing the solutes back to the central region of the droplet. However, the evaporation of a liquid drop is a complicated non-equilibrium system, which is difficult to be controlled, thus much simpler and more effective approaches are needed. This dissertation explores the well-known drying technique, termed ‘freeze-drying’, as a powerful tool to avoid the coffee-ring effect, and describes its efficacy. The dried deposit prepared by the freeze-drying technique resulted in well-dispersed and locally homogeneous features. The method was applied to two following applications, thus confirming its potential use in the future: 1) analytes sampling by drop-deposition for surface-enhanced Raman spectroscopy, 2) nanoparticle deposition on a surface for its size measurement using electron microscopy. The findings in this dissertation have extended further options for uniform coating process by effectively eliminating the coffee-ring effect.한국과학기술원 :전기및전자공학부
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
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