1,721,060 research outputs found
Covalent Rigid-Rod Organometallic Polymers with Alternating Transition Metal Clusters and Conjugated Spacers in the Main Chain
No full textThe first rigid-rod cluster-containing σ-alkynyl polymers E-[({Pt6}-CC-Ar-CC)]x-{Pt6}-E [(3), {Pt6} ) Pt6(μ-PBut2)4(CO)4, E ) end group; Mn ) 22 000-38 000] have been prepared by step-growth polycondensation of {Pt6}Cl2 and 1,4-didodecyl-2,5-diethynylbenzene (HCC-Ar-CCH) under Sono- gashira-type conditions. The monodisperse oligomers HCC-Ar-CC-({Pt6}CC-Ar-CC)x-{Pt6}-CC- Ar-CCH [(4) x ) 0; (11) x ) 2; (15) x ) 4] were also prepared by stepwise procedures, still based on Cu(I)-catalyzed dehydrohalogenation reactions. A red-shift of the UV-vis absorption centered at ca. 470 nm, on increasing chain length, suggests some degree of electron delocalization along the backbone
Roughness Based Passive Control Of Transition To Galloping Of A Circular Cylinder Undergoing Vortex Induced Vibrations
No full textFlow induced motion (FIM) is a naturally occurring fluid-structure interaction phenomenon, typically considered harmful to a wide variety of engineering structures. As a result, the majority of research in the field has been geared towards mitigating the occurrence of FIM. In 2005, Michael Bernitsas at the University of Michigan identified the energy harvesting potential of FIM\u27s, triggering a new line of research that instead focuses on augmenting it. Previous work by our group had tested the effectiveness of strips attached to the surface of a circular cylinder in augmenting FIM modes such as vortex induced vibrations (VIV) and galloping. The objective of the experimental results presented in this thesis is to develop a better understanding of the effect of strip surface on the incitation of galloping oscillations. Strip roughness ratios (ratio of the size of embedded roughness to the total strip thickness) ranging from 0% (smooth surface) to 100% (rough surface with zero thickness) were tested in addition to strip thickness ratios (ratio of strip thickness to cylinder diameter) ranging from 0.8% to 8.2%. At the higher roughness ratios, rough strips led to suppression of VIV and galloping amplitudes when compared to their smooth counterparts. However, with decreasing roughness ratio and increasing thickness, the effect of surface roughness became negligible in comparison to the smooth surface. We conclude that beyond a threshold values of strip thickness, the mechanistic impact of the strip (thickness) is the dominant parameter affecting the cylinder\u27s FIM response with no additional passive flow control possible by varying the surface roughness. At the lower threshold of thickness, neither the smooth nor the rough strips experienced galloping
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
- …
