1,720,978 research outputs found
The Fourier-finite element method for the Poisson problem on a non-convex polyhedral cylinder
No full textWe study the Poisson problem with zero boundary datum in a (finite) polyhedral cylinder with a non-convex edge. Applying the Fourier sine series to the equation along the edge and by a corner singularity expansion for the Poisson problem with parameter, we define the edge flux coefficient and the regular part of the solution on the polyhedral cylinder. We present a numerical method for approximating the edge flux coefficient and the regular part and show the stability. We derive an error estimate and give some numerical experiments. (C) 2009 Elsevier B.V. All rights reserved.X1133sciescopu
An error analysis for the corner singularity expansion of a compressible Stokes system on a non-convex polygon
No full textIt is known that the velocity vector for compressible Navier-Stokes flows with non-zero boundary conditions can be decomposed into a singular part and its regular one near each non-convex vertex of bounded polygonal domains. The singular part is a multiplication of the corner singularity (of the Laplace type) and the stress intensity factor. In this paper we consider a finite element scheme approximating the regular part and the stress intensity factor, show its unique existence of the discrete solution and derive an (nearly) optimal error estimate. Some numerical examples confirming these results are given. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved.X11sciescopu
Multiplexed proteolytic enzyme assay based on energy transfer between quantum dots and gold nanoparticles
No full textEnhanced densification of liquid-phase-sintered WC-Co by use of coarse WC powder: Experimental support for the pore-filling theory
No full textDensification during liquid-phase sintering of WC-Co with various WC powder sizes has been measured in order to identify the densification mechanism. During heating of powder compacts in the solid state, densification was enhanced with a reduction of WC powder size. However, the behavior was reversed when the densification occurred in the presence of a liquid: enhanced densification with increasing WC powder size. This result is in contradiction to a prediction of the conventional theory of liquid-phase sintering, the contact flattening theory, but in good agreement with a prediction of the pore-filting theory. Microstructural analysis further confirmed that the densification at the liquid-phase sintering temperature occurred by pore filling. The calculated densification kinetics based on the pore-filling theory also fitted well with the measured data. The observed densification behavior thus demonstrates experimentally the prediction of the pore-filling theory that the densification is enhanced with increasing average grain size for the same pore size distribution
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
The electronic energy loss of 100 keV heavy ions in medium energy ion scattering analysis of a Ta2O5 ultrathin film
No full textTo optimize the depth resolution of Medium Energy Ion Scattering Spectroscopy (MEIS), a 10 nm Ta2O5 thin film on a Si(100) substrate was analyzed by MEIS using H+ and heavy ions such as Li+, N+ and Ne+ ions. The use of heavy ions such as Li+ and N+ increased the electronic stopping powers 2-3 times but it also increased the electronic straggling compared to H+ ions, For Nef ions, the ion neutralization problem was so severe that the scattering ion intensity from the subsurface layer was attenuated very rapidly and a strong doubly ionized Ne++ peak was observed. For 100 keV N+ and Ne+ ions, multiple scattering peaks were observed.The work is supported financially from the center for molecular science, south korea
A medium energy ion scattering analysis of the Si-SiO2 interface formed by ion beam oxidation of silicon
No full textThe Si-SiO2 interface formed by 3 keV O-2(+) ion bombardment on silicon at room temperature and 600 degrees C was studied by in situ medium energy ion scattering spectroscopy (MEIS). The amorphization process at the initial stage of the oxygen ion bombardment and the subsequent formation of the suboxide layer and the disordered silicon layer at the Si-SiO2 interface were studied as a function of the ion dose from 2.5 X 10(15) atoms/cm(2) to 5 X 10(17) atoms/cm(2) at room temperature and 600 degrees C. After reaching the steady state, below a similar to 6 nm SiO2 layer, a similar to 2 nm suboxide layer and a similar to 3 nm disordered Si layer were observed at the Si-SiO2 interface. The annealing effect at 600 degrees C decreased the number of disordered silicon atoms and the suboxide silicon atoms, which make the Si-SiO2 interface more abrupt, was more clearly observed at the initial stage of the bombardment.Financial supports from the Center for Molecular
Science, Korea, and the Ministry of Science and
Technology, Korea, are appreciated
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