1,720,958 research outputs found
MASS-TRANSPORT STUDY OF NAFION(R) COATINGS SATURATED WITH [OS(BPY)(3)](2+) BY AN ELECTROCHEMICAL QUARTZ-CRYSTAL MICROBALANCE
No full textIon transport out of and into the Nafion(R) coating on an electrode during the electrochemical processes was studied using an electrochemical quartz crystal microbalance (EQCM). After saturated loading of [Os(bpy)(3)](2+), the first cyclic voltammogram (CV) initiated from the lower limit showed an anodic peak around 0.85 V vs. Ag\AgCl which, according to a previous study by Anson's group, corresponds to ejection of the [Os(bpy)(3)](3+) complex from the Nafion(R) coating. However, the frequency change-potential (Delta f-E) curve obtained by EQCM showed an increase in the mass on the first positive scan. These contradictory results can be explained by the movement of water molecules in a direction opposite to that of [Os(bpy)(3)](3+) complexes. After a number of successive cycles, a steady state voltammogram was obtained. In this case the mass change was attributed mainly to the movement of the hydrated electroinactive counter-cations of the supporting electrolyte. The hydration numbers for two of the supporting electrolyte cations are in good agreement with the published results.We would like to acknowledge enlightening discussions with Professor Fred C. Anson and Dr. Minglian Shi. We thank Dr. Chanseung Park for the help with the impedance measurements. This work was supported by the Non-Directed Research Fund, Korea Research Foundation, 1993
SCANNING TUNNELING MICROSCOPE WITH NOVEL COARSE SAMPLE POSITIONING TECHNIQUE
No full textWe have constructed a scanning tunneling microscope with coarse positioning device which enables adjustment of the sample to tip distance into operating range of z-piezo element without stretching for each step of sample approach. This new convenient technique is achieved by monitoring sample current during coarse sample approach. The sample to tip distance of several thousand angstroms could be detected directly on oscilloscope. It is considered that sample current is generated by field emission mode of tip operation or field ionization of air molecules due to a potential induced by sawtooth voltage used for driving inertial piezotranslator. In addition, the topographic images of clusters and ultrathin films of carbon on cleaved graphite will be presented.This work was supported in part by the Basic science research institute program of ministry of education, and in part by KOSEF
Monolayer assembly and striped architecture of Co nanoparticles on organic functionalized Si surfaces
No full textWe present a new strategy to fabricate a monolayer assembly of Br-terminated Co nanoparticles on functionalized Si surfaces by using chemical covalent bonding and microcontact printing method. Self-assembled monolayers (SAMs) of the Co nanoparticles formed on the hydroxyl-terminated Si surface exhibit two-dimensional island networks with locally ordered arrays via covalent linkage between nanoparticles and surface. On the other hand, SAMs of the nanoparticles on the aminopropyl-terminated Si surface show an individual and random distribution over an entire surface. Furthermore, we have fabricated striped architectures of Co nanoparticles using a combination of microcontact printing and covalent linkage. Microcontact printing of octadecyltrichlorosilane and selective covalent linkage between nanoparticles and functionalized Si surfaces lead to a hybrid nanostructure with selectively assembled nanoparticles stripes on the patterned functionalized Si surfaces.KOSEF through the Center for Nanotubes and
Nanostructured Composites, the Brain Korea 21 Project, the Advanced Backbone IT Technology Development Project, the National R&D Project for Nano Science and Technolog
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
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