1,720,966 research outputs found
Synthesis and polymerization behavior of various substituted indenyl titanium complexes as catalysts for syndiotactic polystyrene
No full textFive substituted indenyltrichlorotitanium compounds have been synthesized and characterized by spectroscopic methods and their catalytic behavior for the polymerization of styrene was studied in the presence of methylaluminoxane (MAO) as a cocatalyst. Substituted indenyl ligands include 1,3-dimethyl, 1-methyl, 1-ethyl, 1-isopropyl and 1-(trimethylsilyl)indenyl groups. All five compounds gave extremely pure syndiotactic polystyrene, with conversion rates of at least 95%, and their catalytic properties were compared with the data obtained from the (eta(5)-indenyl)trichlorotitanium-MAO system. The catalytic activity is enhanced by less bulky and better electron-releasing substituents of the indenyl ligand.Korea Science and
Engineering Foundatio
DEVELOPMENT OF REAL-TIME CORE MONITORING-SYSTEM MODELS WITH ACCURACY-ENHANCED NEURAL NETWORKS
No full textCore monitoring models have been developed with use of neural networks for prediction of the core parameters for pressurized water reactors. The neural network model has been shown to be successful for the conservative and accurate prediction of the departure from nucleate boiling ratio (DNBR). Several variations of the neural network technique have been proposed and compared based on numerical experiments. The neural network can be augmented by use of a functional link to improve the performance of the network model. Use of two-fold weight sets or weighted system error backpropagation was very effective for improving the network model accuracy further. Uncertainty factor as a function of output DNBR is used to obtain the conservative DNBR for actual applications. The predictions by the network model need to be supported by extensive training of network and statistical treatment of the data. Studies for further improvements are suggested for the actual applications in the future
First lanthanide complexes and unusual coordination behavior of hexakis(3,5-dimethylpyrazolyl)cyclotriphosphazene
No full textReaction of hexakis(3,5-dimethylpyrazolyl)cyclotriphosphazene (L) with LnCl(3) (Ln = La, Ce, Nd, Sm) affords new mononuclear lanthanophosphazenes [L.LnCl(3)] with hendecahedral coordination polyhedron in which the ligand L employs an unprecedented kappa(5)N binding core consisting of one cyclotriphosphazene ring nitrogen atom and four pyridinic nitrogen atoms of two sets of geminal pyrazolyl groups.financial support provided by the
Korea Science and Engineering Foundation
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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